Bike Maintenance Handbook

Most of this info was taken from the Park Tools Website. If I didn't copy enough of it, you can check it out yourself http://www.parktool.com/index.asp

Best of luck to you. Gotta go work on your bikes now.

Table of ContentChapter 1 Tire and Inner Tube Replacement 4

Removing Tire and Tube From Rim 4 Inspecting the Inner Tube 5 Inspecting the Tire 6 Rim Strip and Rim Cavity 6 Patching an Inner Tube Using Vulcanizing Patch Kit 6 Installing Tire and Tube on Wheel 7 Installing Wheel on Bike 8 Temporary Repair of Tire With Tire Boot 8

Chapter 2 Wheel and Rim Truing 9 Truing Procedure 9

Chapter 3 Brake Service 11 Brake Levers 12 Cable System 12 Calipers and Pads 13 Tangent Alignment 13 Vertical Face Alignment 13 Pad Toeing 13 Setting Pads 14 Pad Wear 15

Chapter 4 Chain Installation 15 Procedure For Shimano Chain 16 Shimano Chain Service Procedure 17 Chain Length Sizing 17 Installing Chain Through Derailleurs 18 Tight Link Repair 19

Chapter 5 Shift Levers 20Chapter 6 Rear Derailleur Adjustment 21

Derailleur Limit Screws (H and L) 21 B-Screw Adjustment 23 Checking the Rear Indexing Adjustment 24 Index Setting 25

Chapter 7 Front Derailleur Adjustment 26 Front Derailleur Height 26 Front Derailleur Rotational Angle 27 Front Derailleur Limit Screw Settings 28 Front Derailleur Adjusting Indexing 29 Front Derailleur Performance 30 Regular Bike Maintenance 31

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Note: "Rear Mech" and "Front Mech" refer to front and rear derailleurs

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Allen keys (aka hex wrench)Spoke wrench / box wrench

Tire levers

Sand paperChain tool

"Vulcanizing glue"

TIRE AND INNER TUBE REPLACEMENTTools needed: Tire levers, air pump, and patch kit or spare tube.

1. For rear wheels, shift derailleur to outermost gear and innermost front chain ring. 2. Release brake quick-release, if any. Typical MTB brakes and road brake quick release mechanisms

are shown below.

3. Release wheel quick-release by pulling quick release lever outward. Pull outward on end of quick release skewer lever. If necessary, loosen quick release adjusting nut to clear any tabs at end of fork.

4. Front wheels guide wheel down and out of fork. For rear wheels, pull back on rear derailleur to allow cogs to clear chain. Lower wheel, guiding the wheel down through brake pads and forward to clear chain and derailleur. Guide the wheel through the brake pads and out the fork ends.

Removing Tire and Tube from Rim Tires can be tightly fitted to the rim. Use tire levers to pry tire bead up and over rim sidewall. Do not use a screwdriver, knife, or other sharp object, which might damage tire or tube. Fully threaded valve shafts may have a locking nut next to rim. Loosen and remove locking nut before deflating.

1. Deflate tire completely. Even a small amount of air left in the tube can make it more difficult to get the tire off. For best results, press downward on wheel while depressing the valve.

2. Push one bead of tire toward rim center. The tire bead will be pressed tight against rim. Pushing it inwards loosens the bead from the rim. Repeat on other bead.

 

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3. Engage one tire lever under bead of tire. Engage second lever 1-2" (25-50mm) from first lever then pull both levers toward spokes to lift bead off rim. Disengage one lever. Move it two inches (5cm) along the rim and engage lever in the bead. Pull lever to lift next section of bead off rim.

4. Repeat engaging the lever until the bead loosens. Then slide the lever along the rim under the bead.5. Starting opposite the valve, pull inner tube from tire. Lift valve from valve hole and remove tube from

wheel. 6. Remove second bead from rim, which removes tire completely from rim. To fully inspect the tube and tire,

it is best to remove both completely.

Inspecting the Inner Tube When servicing a flat tire, always inspect tire and tube carefully to locate the cause of failure. This will help prevent future flats from the same cause.

1. Inflate inner tube if possible. Inflate until tube is twice its normal width. 2. Inspect for air leaks by holding tube close to the sensitive skin of lips or by holding tube near your ear to

hear leaks. Move the tube around its circumference. If these steps do not work, submerge tube in water and watch for bubbles at the hole.

3. If you plan to repair the inner tube, use a marking pen to mark hole. Make four marks, one to each side of hole. Do not mark close to hole, as the mark may be sanded off.

The type of cut or hole in the tube will help determine the cause of the flat. Common causes of tire and tube failures are:

Cut at valve core, commonly from misalignment of tube in rim or riding with low pressure. Be sure tube is mounted straight in rim and check pressure before rides.

Blow causing a large shredded hole. These are usually not repairable. Check tire and rim as well for damage.

Hole on inside edge of tube indicates a problem inside the rim, such as from rim strip failure, a protruding spoke or other sharp object inside the rim.

A long cut or rip may indicate a tire blow out. Typically this is not repairable. Use care when seating tire during installation.

A single puncture or small hole is commonly from a thorn, wire, or small nail. These may be repairable. Check tire as well for thorn, etc.

Double slits are commonly from a rim pinch. The tube was pinched between rim and object in road/trail. Increase air pressure or use wider tires.

V-shaped slits may be from nails or glass.

Inspecting the Tire

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It is important to always inspect the tire as well as the inner tube. The cause of the flat, such as a nail or piece of glass may still be embedded in the tire or tread. Inspect both the outside of the rubber tread and the inside of the casing.

1. Inspect outside of tread for protruding nails, pieces of glass, thorns, or other objects. Squeeze any cut to look inside for objects such as slivers of glass.

2. Visually inspect inside of tire casing for nails, glass or debris. Wipe inside of casing with a rag, and then carefully feel inside with fingers.

3. Inspect sidewall for rips, holes, or damaged rubber and casing. 4. Inspect wire or fabric tire bead for damage.

Rim Strip and Rim CavityThe wheel rim is made with holes between the rim sidewalls for spoke nipples. A rim strip covers the holes or nipples. The rim strip can be made out of different materials such as cloth, rubber, or polyurethane plastic. The strip protects the inner tube from sharp edges in the base of the rim and from spoke ends and nipples that might puncture the tube. Inspect inside the rim cavity, looking at the rim strip and for any sharp corners or protruding spokes.

The rim strip should be wide enough to cover the bottom of the rim, but not so wide it interferes with the seating of the tire bead. Inspect the rim strip whenever changing a tire or inner tube. Look for tears and rips, and make sure rim strip is centered over the nipple holes.

Patching an Inner Tube Using Vulcanizing Patch KitGlue type patches require the application of a thin layer of self-vulcanizing glue on the tube before the patch is applied.

1. Locate hole marked during inspection, as described above.

2. Using fine emery cloth or sandpaper, lightly abrade area around hole. Abrade an area larger than patch size.

3. When possible, clean area with alcohol and allow it to dry completely.

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4. Open glue tube and puncture seal. Apply thin coat of glue and spread evenly around hole area. Spread area of glue larger than patch size. Use a clean finger or back of patch to spread glue evenly in a thin layer. Do not apply too much glue. Glue layer should not appear "glopped" on.

5. Allow glue to dry. This may take several minutes. Test by touching only perimeter area of glue, not where patch will contact.

6. Peel patch from patch backing. Handle patch only by edges. 7. Center patch to hole and lay patch on tube.

8. Apply pressure to patch, especially at edges. 9. If possible, maintain pressure for several minutes. 10. Leave clear plastic cover on patch, do not peal up.

Installing Tire and Tube on Wheel1. Note directional arrows of tire manufacturer, if any. Directional arrows printed on the sidewalls indicate

rotation of wheel. Not all tires have direction orientation. 2. Inflate tube enough for tube to just hold its shape. 3. Install tube inside tire. Install with tube valve adjacent to air pressure recommendations written on tire

sidewall. 4. Lower tire and valve into rim valve hole and align valve so it is pointing straight toward hub. A crooked

valve can lead to a flat tire later. 5. Install one bead at a time. Work tire bead onto rim with hands. If tire bead will not seat using hand, use

tire lever as a last resort. Use caution when using tire levers to avoid pinching inner tube. Engage tire lever using same orientation as removing bead.

6. Work tube over rim sidewall and into rim cavity. 7. Install second bead onto rim. Use care if using a tire lever. 8. Inspect both sides of tire for bead seating and for any sign of the inner tube sticking out. Re-install if

necessary. 9. Inflate to low pressure and inspect bead again on both sides. Look for small molding line above bead. This

line should run consistently above rim.10. Inflate to full pressure and check with pressure gauge. It may be necessary to press downward above the

valve in order to engage the pump head. For fully threaded valve shafts, re-install the locking nut, if any. Do not use wrench or pliers to tighten nut. Tighten finger tight.

Installing Wheel on BikeThe wheels must be properly mounted to the bicycle frame. Misalignment can result in problems with shifting and bike handling. If the wheel is not securely mounted in the dropouts, it may come out when the bike is ridden, possibly causing injury to the rider.

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Quick release wheels use a hollow hub axle fitted with a shaft, a lever that operates a cam mechanism, and an adjusting nut. The cam puts tension on the shaft and pulls both the cam and the adjusting nut tight against the dropouts. This tension is what holds the wheel securely to the frame. The adjusting nut determines the amount of tension on the quick release lever and cam. Lubricate the cam mechanism if it appears sticky or dry.The quick release is fitted with two conical shaped springs. The small end of the spring faces the axle, and the large end faces outward. These springs make the wheel easier to install. If one or both springs become twisted or damaged they may be removed. The springs serve no purpose once the wheel is tight on the bike.

1. Check that the quick release skewer lever is in open position. Check that brake quick release mechanism is open.

2. Install front wheel between dropouts with skewer on left side (from rider's point of view). Pull wheel fully up into dropouts.

3. Rear wheels, pull back on rear derailleur to open chain. Place smallest cog between upper and lower sections of chain. Guide wheel between brake pads and engage smallest cog on chain.

4. Determine final closing position of hub quick release lever. Rotate front lever and adjusting nut so the lever will end up just in front of fork. Position the rear lever so it falls between the chain stay and seat stays. Reposition the lever as necessary if it will not fully close.

5. Adjust closing tension of quick release skewer. For most skewers, hold lever parallel to the hub axle, which is half way through its swing from fully open to fully closed. Tighten adjusting nut snug against dropout. Check results by moving lever back and forth through its swing. Lever should meet resistance to closing half way through its swing. Close lever fully.

6. Close brake quick-release mechanism. View wheel centering in fork. Wheel should be centered between fork blades. To adjust wheel centering, open skewer, move wheel either left or right until wheel appears centered, then close skewer. For non-quick release wheels, loosen axle nuts and center wheel, then tighten nuts fully.

7. Inspect brake pad alignment and centering by closing and opening pads with brake lever. If brake pads are not centered to wheel, see Chapter on Brake Systems. If wheel fails to adequately center in frame, either the frame or wheel may be miss aligned.

8. Spin wheel and double check pad alignment to rim. Be sure pads do not strike tire. 9. Orient skewer so lever will end up between the seat stay and chain stay, unless this prevents lever from

fully closing. 10. Attach MTB brake release wire. 11. View centering of wheel between chain stays and seat stays. Also sight rim centering to brake pads. Open

skewer and adjust as necessary to center wheel in frame. If brake pads are not adequately centered to wheel re-adjust brakes.

Temporary Repair of Tire with Tire Boot If the tire has been ripped and the casing damaged, it may not hold an inner tube. It is possible in some cases to make a temporary repair with a Tire Boot. A booted tire should not be considered a permanent repair. The tire should be replaced as soon as possible.

1. Locate rip in tire. Compare rip to size of tire boot. Tire boot must completely overlap rip to be effective.

Align boot so edges do not extend beyond tire bead. If necessary, cut boot so it does not extend past tire bead.

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WHEEL AND RIM TRUING

Typical Tools and Supplies Needed:

Spoke Wrench, purchased to fit nipples

This article will discuss the truing of the common spoked bicycle wheel. The wheels drive the bike forward when we pedal, allowing us to roll down the road or trail. Having wheels that spin straight and round adds to the bike's performance. Spokes allow adjustments to the tension on the rim that will affect how straight the wheels spin. The wheels also help slow the bike. Rim caliper brakes, such as linear pull, cantilever, side pull, and dual pivot brakes use the rim sidewall as the braking surface. There may be problems during the ride and when braking if the wheel wobbles side to side, or is "out-of-true". Brake pad adjustment will also be difficult with an out-of-true wheel. The typical bicycle wheel is composed of a rim suspended with tensioned spokes around a center hub. Each spoke pulls on a section of rim. Spokes coming from the right side hub flange pull the rim to the right. Spokes coming from the left side hub flange pull the rim to the left. Spokes attached at the rim are then offset in a left-right-left-right pattern to counter the pull of the other side. Having all the spokes tight with fairly even tension makes the wheel true and strong. Changes to spoke tension will pull on the rim and affect its true. This process is called "truing".Truing is occasionally needed to keep the rim running straight as it spins between the brake pads. Spoke tension is adjusted by tightening or loosening a threaded nut, called the nipple, at the end of the spoke. Spoke threads typically use right-hand threads. Although a common phrase among mechanics is to "tighten the spokes", it is the nipple that is turned, not the spokes.To adjust tension at the nipple, first select the correct wrench. Spoke nipples are typically square, and come in different sizes. The correct wrench is the smallest size that can be used, even if it seems slow putting the wrench on the nipple. Make sure the wrench is fully engaged on the nipple before turning. A wrench that is partially engaged may damage the nipple and make truing difficult.

When truing a wheel, the wrench and nipples may end up being viewed upside down. This happens if the wrench and nipple is viewed below the axle center. The wrench will appear to the mechanic as turning to the left when tightening the nipple. Do not allow this to confuse you. Keep in mind that the nipple is rotating around the fixed spoke, the spoke does not rotate. If in doubt, imagine a screwdriver at the nipple end, and turn it clockwise or counter-clockwise as needed.There are four basic aspects of wheel truing. These are lateral true, radial true, rim centering over the hub, and spoke tension. Professional mechanics are able to adjust spoke tension so each aspect is optimal. Using truing stands, centering tools, spoke tensiometers, and experience, a professional will produce a durable and strong wheel. LATERAL TRUE: this true is also called "rim run-out", and is the side-to-side wobble of the rim as the wheel spins. This aspect is the most critical to brake caliper settings.RADIAL TRUE: this is the amount of up and down wobble. If the wheel becomes out-of-round, it wobbles up and down with each revolution. In severe cases this will affect brake pad placement and can be felt by the rider as a bump every wheel revolution.RIM CENTERING or "DISH": this refers to the rim being centered in the frame. If the rim is offset in the frame to either side it may be difficult to adjust the brakes. Severe cases of poor centering can also cause handling problems, because the rear wheel will not track behind the front wheel. TENSION: this is simply the tightness of the spokes. Spokes are tensioned just like other fasteners.

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Truing ProcedureThe procedure described here emphasizes lateral true, which most affects the caliper brake. The idea is to get the wheels true enough to avoid hitting the brake pads. The other aspects of truing such as radial, centering and tension are important. For the novice mechanic, it is best to begin with lateral true in order for the brakes to work properly. The image below is a "mechanic's eye" view of the rim. The spoke nipples labeled A, C, and E are on the left side of the rim and come from the left side flange. Spoke nipples B, D, and F are on the right and come from the right side flange. Left side spokes tend to pull the rim toward the left. Their pulling is offset by the pull of spokes on the right. Each nipple effects relatively wide area of the rim. For example, spoke C will pulls mainly adjacent to its location, but will also effect the rim up to and even past A and F. Tightening nipple C increases spoke tension and moves that section of rim to the left. Tightening nipple D will tend to move the rim to the right. Loosening nipple C will also tend to move the rim to the right, because on the constant pull of D.

In order to see rim movement, a steady pointer is useful as a reference. A wheel-truing stand allows easier and more accurate work. It is also possible to use anything that can hold the wheel steady as a truing stand, such as the frame. A pointer can be created by using the brake pads. Radial truing and rim centering are typically not an issue when only minor corrections are made. It can help to remove the tire while truing.

1. Remove wheel from bike and remove tire. (NOTE: for lateral truing, the tire can remain in place.) 2. Lubricate the threads of the spokes and where the nipple exits rim.3. Bring calipers up to rim level. Generally, place caliper tips close to outer end of braking surface. Or,

pretend brake pads are calipers. 4. Spin wheel. 5. Stop wheel where rim and indicator are closest, at the point of the scrape. 6. Rotate rim back and forth past caliper and find center of rim deviation. 7. If the rim deviation is moving toward the indicator, this section of rim needs to move away from caliper.

A. If rim touches left side caliper, find closest nipple to center deviation coming from right side of hub flange.

B. If rim touches right side caliper, find closest nipple to center deviation coming from left

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side of hub flange.

8. Tighten nipple 1/2 turn. Move wheel back and forth in this area and check deviation again. 9. Spin wheel and locate another side-to-side deviation using indicator. Again slow and stop the rim where

rim approaches indicator. Locate closest nipple opposite to center of deviation tighten nipple. If nipple appears especially tight, loosen spoke on same side as rub on indicator.

10. Repeat until wheel is true. Wheel is adequately true if it wobbles less then 1/16" (1.0mm). 11. Clean rim braking surface with a solvent such as rubbing alcohol or a window cleaner.

Brake Service

MTB-type Brake Lever Cable AttachmentThe MTB-type brake cable uses a disc shaped end. The lever will have a fitting in lever for this disc. Typically, begin by lining up a slot in the adjusting barrels.

SRAM® levers feed from the inside through the lever body. For Shimano® type levers, engage cable end in lever first, the fit into adjusting barrel.

LINEAR PULL BRAKE SERVICE (V-BRAKE TYPE)

How Do I Work on My Linear Pull Brakes?

Useful Tools and Supplies: Hex wrenches (5mm and/or 6mm), light liquid lubricant

Service ProceduresProperly adjusted brake systems require attention to small details. This article will begin by discussing the brake lever, inner wire fitting at the lever, and brake housing. Caliper attachment to the frame, pad adjustment to the rim, and pad centering and clearance are then reviewed.

Brake LeversBrake levers should be positioned so they are easy and comfortable to reach. Loosen the lever mounting bolt and rotated the lever so it is in line with the rider's arm, making it comfortable to reach and use. Re-secure brake lever body. Additionally, brake levers commonly have a setscrew on the lever body that allows the lever to be set closer to the grip. Use reach-setting screw to adjust lever reach according to hand size and riding style.

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Cable SystemThe cable system connects the brake lever to the caliper at the wheel. The brake inner-wire has a fitting on one end, which sits in the lever. The brake inner wire end is held by the lever. The common system is shown below. Align the slot in the barrel adjust with the slot in the lever body. Fit the disc into the lever and pivot the wire into the adjusting barrel. Turn the barrel to hold the inner wire in place. The Shimano® levers may use a clamp on the lever. Pull this clamp upward, and fit the inner wire disc in place.The inner-wire passes through a brake housing, which allows the inner-wire to connect from the levers to housing stops on the frame. Housing also allows for bends around corners on the way to the brake caliper.

Calipers and PadsLinear pull calipers are attached to the frame or fork at the "braze-on". If you are mounting the calipers or have removed them, grease the braze-on before installing the caliper. There may be three different spring hole options, it is typically best to choose the middle hole.Brake pads are bolted to the caliper arms. When the bolt or nut is loosened, they can be adjustable in several directions. The pad should be correctly adjusted for vertical height alignment, tangent alignment, vertical face alignment and pad toe. Not every brand or model of brake caliper has every adjustment, and sometimes you must simply compromise when setting pads.Vertical height alignment: This is the setting up and down on the rim-braking surface. View caliper face-on and move the arms, watching the pads move to the rim. For most linear pull calipers, set the pad to the upper edge of the rim-braking surface.

Tangent AlignmentThis is the setting of the pad tilt. Viewed pad from the side, the front and back of the pad should be level to the rim. One side should not be higher or lower than the other side. Use care when tightening the pad fixing bolt and hold the brake pad to keep it from twisting.

Vertical face alignmentThis is the setting of the pad vertical surface relative to the rim vertical surface. The vertical face of the pad should be set parallel to the face of the braking surface.

Pad ToeingThis is the setting of pad angle as it touches the rim. Toeing refers to setting the pad so the pad's front edge strikes first, which tends to reduce squeal during braking. Caliper arms tend to have play in the pivots and the

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arms flex when the brake is applied. This may cause squealing in the brake pads. It is simplest to first ride the bike and see if the brakes squeal.

Front of pad strikes rim first for "toe". Most models of linear pull calipers use a "threaded stud brake pad." Some models use a smooth stud pad with fixing bolt. For the threaded stud types, a threaded bolt is fixed into the pad. The bolt is sandwiched to the caliper arm by a series of convex and concave washers, creating a ball and socket system. The bolt and pad move in the caliper arm for toe and vertical face alignment.

Threaded-stud pads use curved washers to align pad face to rim.

Setting PadsBefore setting pads, begin by double checking that wheel is adequately centered in frame. If wheel is moved from current position, pad alignment will be effected.

1. Loosen pad nut/bolt and lubricate curved washers and thread. Adjust one pad to the rim at a time. 2. Push caliper arm to rim and view pad alignment. Align pad correctly in four positions.

o Set pad vertical height on rim braking surface. o Set pad vertical face to be parallel to rim face o Set front and back edge of pad should be level to rim, so it is tangent to rim. o If toeing with shim, set so front edge and back edge with rubber band should be touching rim at

same time. 3. Tighten pad nut. Inspect pad alignment again. 4. Repeat alignment of other pad.

Attach inner-wire to brake caliper. Secure wire fixing bolt. Squeeze lever hard several times and set pad clearance at lever for rider preference. If brake feels tight, turn barrel adjuster into lever clockwise to loosen inner-wire tension. If brake feels too lose, turn barrel adjuster counter-clockwise to tighten inner-wire tension. If barrel adjuster is all the way engaged at lever and brake lever still too tight, loosen inner-wire pinch bolt and allow slack to feed through pinch plate. Tighten pinch bolt and test again, doing final adjusting at brake lever barrel adjuster.

Use barrel adjuster to set tightness of pads to rim.

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Inspect pad centering to rim. Use set screw on sides of caliper to center pads to rim. Tighten setscrew on arm with pad that is closest to rim. Inspect that pads are not rubbing tire. Re-adjust if necessary. Clean the rim surface and test ride bike.

Use centering screws to move arms and center pads to rim.

Pad WearPads will wear out with use and require replacement. Pads will also harden and become ineffective with age. Pads may also become embedded with aluminum or other contaminants. Inspect and remove as necessary. Pads that are aligned too low on a rim will tend to develop a lip on the low edge. This lip makes correct alignment impossible.

NOTE ON REAR SUSPENSION: If the bike has a rear suspension linkage, it is usually necessary to account for the movement of the rear hub from the bottom bracket. If the rear hub moves away from the bottom bracket, set chain length is the longest position. Consult the bike manufacturer for correct chain length if in doubt.DERAILLEUR CAPACITY: The derailleur capacity refers to the derailleurs ability to take up chain slack as the derailleur shifts between different gear combinations. Some bicycles may have sprocket combinations that do not allow the derailleur to take up the chain slack. In this case, the gearing on the bike exceeds the capacity of the derailleur. If the derailleur capacity does not match the gear sizes on the bike, the chain may appear to fail either the “too long” test or the “too short” test. A chain length cannot be found that will pass both tests. In this case it is better to size a chain for too long rather than too short. Both the EXISTING CHAIN and EQUATION methods below will safely size a chain when a bike is violating the derailleur capacity. It may be necessary to avoid gear combinations that cause problems in pedaling or shifting on these bikes.

CHAIN INSTALLATION

Typical Tools and Supplies Chain Tool Chain Lube Rags

This article will discuss the removal and installation of chain on derailleur bicycles.

Chains are made up of a repeating series of inner plates, a roller, a chain rivet (also call a "pin"), and outer plates. The chain rivet presses into both outer plates,but the rivet slides freely through the inner plates and the roller. Chains have a small amount of play at each link, even when brand new. As a chain is ridden, it wears the rivets, and the play at each link increases. This is sometimes called "stretch", although the plates do not literally become longer. A worn chain will not engage the cogs correctly, and will eventually slip over the cog teeth when pressure is applied. New chains can be fitted to the bicycle, although new chains are longer than required and must be shorted to the correct length.

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To install or remove a chain, a chain tool is required. Chain tools are made up of a driving pin and a cradle to hold the chain-roller. Some models have two cradles. The primary cradlesupports the chain plate for pressing the chain rivet in and out. The tight link cradle is only for fixing a tightlink. The service procedure will vary between brands of chains. Always check theinstallation instructions on a new chain.

When installing a chain, keep in mind that most chain failure is due to one of the pins being improperly installed. Modern chains are very narrow, and even a small amount of misalignment in rivet as it sits in the side plates could cause the chain to break under load. Check even new bikes by viewing each and every pin for protrusion at the side plates.

Procedure for Shimano® ChainSome chains, including Shimano®, use chain rivets which are peened. This creates a "mushroom" effect at the ends of the rivets, which adds to the strength of the chain side plates. When a rivet is pressed even partially out, this peening is sheered off on the side pressed by the chain tool. If this rivet were reused, it would create a weak link at that rivet. Shimano® chains use a special replacement rivet when the chain is installed new or when one is removed and re-installed. This replacement rivet has special flaring that is guided in by a long tapered pilot. The pilot is then broken off before riding. Only Shimano® brand chains should use the Shimano® replacement rivet. The 7 and 8 speed chains use a black rivet. The narrower 9 speed chain uses a silver-colored rivet.

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Shimano® Chain Service Procedurea. Select a chain rivet that has peening marks. These may be either double peening marks (two parallel marks at rivet ends), or a peening completely around the rivet. Avoid selecting the special replacement rivet, and avoid any rivet that looks different from the others.

Some Shimano® chains use a rivet around the entire head.b. Place the roller of the chain fully in the primary cradle of the chain tool.c. Turn the chain tool pin until it contacts chain rivet and stop. Note position on handle.d. For most non Park Tool brand chain tools, turn handle 5complete turns. Use care not to drive outchain rivet. e. Back out chain tool pin and lift chain out of cradle.f. Grab chain on either side of protruding rivet. Flex chain toward the protruding chain rivet then pull on chain to separate.

g. Pull on non-rivent end to remove chain from bicycle.To reinstall the special replacement rivet:a. Reinstall chain on bike with protruding chain rivet facing away from you.b. Open outer plates slightly and insert inner plates. Align protruding rivet with hole in inner plate.c. Install special Shimano® replacement rivet into chain rivet hole, with tapered end first. Replacementrivet will protrude outward toward you.d. Back chain tool pin into tool body to make room for replacement chain rivet.e. Place roller into primary cradle of chain tool.

f. Drive replacement rivet into chain. Replacement rivet will drive out original rivet. Continue to drive until chain tool pin is almost adjacent to outer side plate.

g. Remove the chain from tool and inspect rivet. Non-tapered end of replacement rivet should protrude same as any neighboring rivet. Press further if necessary. Image below shows a protuding chain pin. Repair as necessary.h. Break off pilot of replacement rivet. i. The replacement chain rivet should not be used again to separate the chain. Re-using same rivet hole wears plate holes and may weaken chain. Use other original rivets for future chain cutting.j. Inspect for tight links and repair as necessary. Shift to a gear that will relax derailleur cage. Pedal backwards and note any hoping or jumping of chain as it passes through pulleys. See also Tight Link Repair.

CHAIN LENGTH SIZING

Typical Tools and Supplies Chain Tool

Chains for derailleur bicycle should be an adequate length. A chain that is too long or too short can cause shifting

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and riding problems. However, the rear derailleur cage should be long enough to take up slack as the chain is moved between the different gear combinations.

Chain Sizing - Largest Cog and Largest Chainring MethodAn alternative method for determining chain length for new chains is to use the largest size sprockets on the bike. It is easiest to size the chain without threading it through the derailler.

1. Remove the old chain. 2. Shift the front derailleur over the largest chainring, and the rear derailleur on the smallest cog. 3. Thread the new chain through the front derailleur. It is not necessary to thread the chain through the rear

derailleur at this point. Simply wrap the chain around the largest front chainring and around the largest rear cog.

4. Pull the chain tight, and note the closest rivet where the two could be joined. Keep in mind a chain can only be joined by mating inner and outer plates.

5. From the closet rivet, lengthen the chain by counting over an additional two rivets (two links), which is a distance of one-inch. Cut the chain at this point.

Remove the chain from the bike and thread it through both derailleurs and join the ends.

Installing Chain Through DerailleursThe chain is routed through the rear and front derailleurs before being joined. It is best to first determine chain length before instaling chain.

a. Shift front and rear derailleur under smallest rear cogs.b. Pull back on rear derailleur and feed short section of chain over the tension pulley and straight to the guide pulley.

c. Pull chain behind rear cogs and then foward toward front rings.

d. Hold a short section of chain and feed chain through front derailleur cage. Turn cranks slowly as you feed chain onto smallest ring.

e. Joint chain at lower section between front and rear cogs. Use correct procedure according to brand of chain. See process above.

f. After installing the chain, check for any tight links. Before riding the bike, check the derailleur

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adjustment.

TIGHT LINK REPAIR

Typical Tools and Supplies Chain Tool with loosening shelf option Chain Lubricant Rags

This article will discuss loosening a tight link on a derailleur chain.

Tight links are typically the result of the two outer chain plates pushing tightly against the inner two chain plates. If pressure on the inner plates can be removed, the tight link can be fixed.Some chain tools have a tight link repair system built into the tool. The following procedure demonstrates how to use the tight link repair system.

1. Locate the tight link. Put chain in smallest rear sprocket in back and on the middle ring of a triple crankset, or the smallest ring of a double crankset. This relieves tension on chain and makes problem links show up easier.

2. Back pedal slowly and watch chain as it passes through the two jockey wheels of the rear derailleur. Look for a popping or jumping of chain, or movement in derailleur arm. Keep backpedaling slowly. Tight link should show up as it passes by the tight bend of the lower jockey wheel.

3. Isolate tight link and move it to lower section of chain between chainring and rear cogs. 4. Engage tight rivet in tight link cradle. 5. Run chain tool pin up to tight pin and note position of handle. 6. Turn handle only one-eighth to one-quarter turn clockwise. This presses on rivet to spread chain. 7. Remove chain tool and feel tight link. 8. Repeat as necessary, pushing rivet from other side of chain. 9. Inspect chain rivet. Rivet must be centered in chain plates.

Tight Link Repair without Chain ToolIt is also possible to repair tight links without the tight link cradle system. This method requires physically stressing and flexing the chain laterally. Use care not to bend and deform the plates by using too much force. To avoid damaging your chain, practice on a section of scrap chain. Your hands are likely to get dirty from grabbing the chain. If this is a problem use a rag over the chain.

1. Locate the tight link as described above. 2. Grab either side of chain with your hands, and place both thumbs at the tight rivet. 3. Pull outward with your hands, while pressing inward with your thumbs to flex the tight link. 4. Reverse pressure to flex chain the opposite direction. Pressing inward with your hands and pressing

outward with the index fingers centered on tight rivet.

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5. Pivot link back and forth to see if it is free and repeat if necessary.

SHIFT LEVERS

Useful Tools and Supplies Hex wrenches

This article will discuss the cable (inner wire) installation in brake and shift levers.

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SRAM® Shift LeversSRAM® shift levers are commonly called Grip-Shift. The levers mount to the handlebar between the brake levers and the grips. The lever may be rotated on the bar so the cable housing exits without interference.There have been different generations of the Grip-Shift levers, and cable installation of the derailleur wire can vary. The modern lever has an access hole with a plastic or rubber cover. Shift the lever to the most relaxed cable position. Remove the cover. Pull the old cable from the shifter by pushing the cable toward the lever.

Some models may have a small set screw over the cable end. Use a hex wrench to remove this screw.

On some SRAM® models the cable end may be held in the lever by a small clip. Usea small screwdriver to pry back this clip, and then push the cable end out.

Pry clip back to access cable end.

Feed the cable in and out through access hole.

Rear Derailleur AdjustmentTypical Tools and Supplies Needed:

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Remove cover to expose cable end Remove set screw.

Screwdriver, Phillips #2 or straight blade Hex Wrenches Light lubricant Cable cutter, if trimming cable CN-10 Rags

Derailleur bicycles have several sprockets on the rear hub. By using different combinations, the rider will find low gears for going up hill and high gears for going down hill. The gear system needs maintenance and adjustment to perform well. The cable system may also need replacement as it wears. The derailleur limit screws and index setting will need periodic checking. This article will first discuss limit screw setting, and then index adjustments.

Derailleur Limit Screws (H-Screw and L-Screw)Rear derailleurs "derail" or shove the chain off of one sprocket and move it to another. The upper derailleur pulley (called the "guide pulley") pushes the chain to the next sprocket. A proper gear adjustment aligns the guide pulley under the sprocket.Changes to the inner wire tension cause movement in the derailleur. The derailleur body is fitted with a spring that is pulled tight, or relaxed, by the inner wire. Pulling the inner wire moves the derailleur cage and guide pulley in one direction and tightens the spring. Relaxing inner wire tension allows the spring to move the body and pulley in the opposite direction.It is normal for a chain to make some noise during a shift. The shift may appear subjectively "noisy," "loud," or "rough". Factors like the type of chain or sprocket, the wear on each, and the amount and type of lubrication will affect the noise a chain makes during shifting. The limit screws typically can do nothing to affect the noise during a shift between cogs. Noise from the chain as it rides on the sprocket is, however, a useful symptom. There is for any given bike a "base level" of noise from the chain as it passes over the sprocket teeth. When the derailleur jockey wheel is out of alignment, the chain may make excessive noise. To demonstrate the "base level" noise, shift the bike to the second sprocket by pulling the inner wire. Continue to pedal and move the inner wire slightly to hear changes in the level of noise. The quietest level of noise may be considered the base level for that bike.Derailleur pulleys are limited in both inward and outward motions by using the derailleur limit screws. Properly set, the derailleur will shift to both the extreme outward sprocket (the smallest in size) and the extreme innermost sprocket (the largest in size). The limit screws do not control the derailleur on the sprockets between the two extremes. These are set using the barrel adjuster and tension on the inner wire. The limit screws are usually marked "H" and "L". The "H" controls the outer most limit of the derailleur, and the "L" controls the inner most limit.

Using the shift lever to adjust limit screws can cause confusion and problems because it tends to focus attention on the inner wire tension (indexing) rather than limit screw settings. Instead of using the shift lever, pull the inner wire with one hand to simulate shift lever action. This will help eliminate confusion between indexing problems and limit screw problems. With the bike in a stand, practice shifting with this method before adjusting the limit screws.

Turning the limit screws adjusts the limit of travel of the pulleys. Tightening restricts the travel, while loosening allows more travel. The purpose of the following procedure is to find the tightest H-limit screw setting that will allow a good shift to the outermost cog, and the tightest L-screw setting that will allow a good shift to the innermost cog. The location of limit screws on the derailleur body may vary between manufacturers. Always look for the "H" and "L" marked adjacent to the screws.

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H-Limit Screw Shift chain to outermost (largest) chainring (Chainrings are the front gears). Shift chain to outermost rear sprocket (smallest sprocket). Check tension on rear inner wire. If inner wire appears to have any tension, it may interfere with the H-screw setting. Turn adjusting-barrel clockwise to eliminate inner wire tension. Proper cable tension (indexing) will be adjusted later. Pedal bike at a quick cadence, approximately 60 rpm or more. Pull inner wire to shift derailleur one sprocket inward. Adjust pull on inner wire until chain rides quietly on second sprocket. Release inner wire quickly to shift back to outermost sprocket and note shift. When adjusting the H-screw, be concerned with two situations:

1. The outward shift from the second sprocket to the outermost sprocket. 2. How the chain rides on the outermost sprocket. 3. Do not be concerned with how the chain rides when it is held on the second sprocket. 4. If the shift outward seems acceptable, tighten H-screw 1/4 turn clockwise and repeat shift. Even if shift

appears acceptable, continue tightening H-screw by 1/4 turn increments and checking shift until shifting is slow or hesitant. Another symptom of a too tight H-limit screw is when the chain is on the smallest cog but makes a rattle from rubbing the second sprocket inward. View this last symptom by looking under the rear sprockets where the chain meets the sprockets. The inner plate of the chain will rub against the next sprocket inward making the noise.

5. When symptoms of a too tight H-screw appear, loosen H-screw 1/4 turn and check shift again. Repeat process of shifting and correcting by 1/4 turn increments. When too tight symptoms disappear, H-screw is at tightest acceptable setting, and limit screw setting is done.

NOTE: "Rapid Rise" or "Low-Normal" derailleurs use a reverse spring application. When the inner wire tension is completely relaxed, the derailleur sits on the inner most sprocket, which is reversed from other common derailleurs. When adjusting the H-limit screw, it is necessary to pull the inner wire until the chain is in the second to outermost sprocket then pull hard to shift to the outermost sprocket. The same concept is used to adjust the Shimano® "Rapid-Rise" or "Low-Normal" derailleurs. You want the tightest limit screw setting that allows good shifting to the extreme outer and inner cogs.

L-Limit ScrewThe L-limit stops the derailleur from moving inward (toward the spokes). The limit screw does not make the derailleur move, pulling the inner wire makes the derailleur move. The L-screw allows the pulley wheels to shift the chain to the innermost sprocket and yet not shift off the sprocket into the spokes.

1. Shift bike to middle chainring (front gears) and to second-to-innermost rear sprocket. 2. Pedal bike at a quick cadence, approximately 60 rpm or more. 3. Pull inner wire by hand to shift derailleur sprocket inward. When adjusting the L-screw, be concerned with

two situations: 1. The inward shift from the second-to-innermost sprocket to the innermost sprocket. 2. How the chain rides on the innermost sprocket. 3. If shifting seems adequate, tighten L-screw 1/4 turn, and repeat shift. Continue to tighten L-screw

until symptoms of too tight appear. These symptoms are that the chain will not complete shift even with pressure on inner wire, the chain hesitates before shifting inward even with constant pressure on inner wire, or the chain rattles excessively when riding on innermost sprocket

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4. When symptoms of a too tight L-screw appear, loosen L-screw 1/4 turn and check shift again. Repeat process of shifting and correcting by 1/4 turns. When too tight symptoms disappear, L-screw is at tightest acceptable setting, and limit screw setting is done.

B-Screw Adjustment

After setting the L-screw, check the "B-screw" for an adequate setting. The B-screw controls the derailleur body angle, hence the name, B-screw. Shift to the innermost rear cog, which is the largest cog. View the upper pulley relative to the largest cog. If the pulley is rubbing against this cog, tighten the B-screw to increase upper pivot spring tension, which pulls the pulley back and away from the cog. If there is a large gap between the upper pulley and cog, loosen the screw. To find a good setting, loosen the B-screw until the upper pulley begins to rub, then tighten the screw to get clearance.

Check for rubbing of largest sprocket and upper pulley

Change B-screw as necessary

Checking the Rear Indexing Adjustment

The rear indexing adjustment should only be done after the H-limit and L-limit screws are adjusted. The rear derailleur indexing is adjusted by changing the inner wire tension. For the common rear derailleurs,

 

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increasing inner wire tension tends to move the rear derailleur more to the left, or toward the spokes. Less inner wire tension tends to move the derailleur to the right. The inner wire tension will not stop the derailleur at its extreme limits. The H-limit screw stops the derailleur at its right most setting, and the L-limit screw stops the derailleur at its left most setting. (Shimano® or "Low-Normal" derailleur are a bit different, see procedures at the bottom.)

Modern indexing shift levers use dwell, which is a hesitation between movements in the lever. These hesitations are timed to match the movements of the derailleur and the spacing in the rear sprockets. The design of some derailleur and shift lever brands requires more of a push (or twist) of the lever to complete the shift. The amount of extra push or twist is not consistent between manufacturers and each rider must learn the particular attributes of his or her system.Changes to inner wire tension are made at the adjusting barrel. Adjusting barrels may be located either at the rear derailleur or at the shift lever. The goal of adjusting the indexing is to find the tightest inner wire tension setting that will allow good shifting to the gears normally used. This will allow the longest lasting indexing adjustment as the system wears and the cable system stretches with use. To find the tightest inner wire setting, you will purposely make the setting too tight then relax tension slightly. There are two basic symptoms for a "too tight" inner wire. These are a rattling noise from the chain rubbing against the next cog inward, and a slow or hesitant outward shift. These are symptoms for rear derailleurs that sit outward when inner wire tension is released.NOTE: If the cable inner wire is not correctly routed into the derailleur pinch bolt, a good indexing setting may not be possible. The wire should leave the barrel adjuster and travel straight to the pinch mechanism. The upper image is correctly routed, while the lower image shows incorrect routing.

Index SettingA. Set limit screws (if not already done). B. Shift chain to outermost rear sprocket (smallest). Shift chain to outermost (largest) chainring in

front. C. Test initial inner wire tension. Pedal a normal cadence and shift rear derailleur with one click on

lever. Use care to only move lever one position. If derailleur moves one sprocket, tension is adequate.

D. If derailleur fails to shift one sprocket, inner wire may be too slack. Turn barrel adjuster fully into derailleur body (or shift lever) then turn counter clockwise two turns to allow for index adjustments. Loosen inner wire pinch bolt and gently pull on inner wire with fourth hand tool or pliers to remove slack. Tighten inner wire pinch bolt.

E. If derailleur will not shift one sprocket after removing slack in "d", return lever back to outermost sprocket position and increase inner wire tension by turning barrel adjuster counter-clockwise 1/4 turn and attempt shift again.

F. Shift to second sprocket in rear. Pedal and increase inner wire tension by continuing to turn adjusting barrel counter-clockwise until a definite rattling is heard. Rattle is from chain scrapping against next sprocket.

G. Once a too-tight rattle is achieved, turn barrel adjuster 1/4 turn clockwise, to release inner wire

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tension, and pedal again. Listen and look for signs of scraping or rattling. Continue turning barrel adjuster 1/4 turn clockwise at a time until rattle disappears.

H. Shift derailleur one sprocket inward at a time, listening for signs of rattle, indicating a too tight inner wire. Turn adjusting barrel 1/4 turn clockwise to eliminate rattle. Note: Do not attempt shift to largest rear sprocket while in largest front sprocket. This gear is normally not used and adjusting tension to this shift may compromise other commonly used gears.

I. Shift to innermost (smallest) chainring and check gears again. If no rattling is present, index adjustment is done.

Shimano "Rapid Rise" or "Low-Normal" Derailleur Indexing Adjustment

Shimano "rapid rise" or "Low-Normal" derailleurs use a return spring that puts the derailleur under the innermost rear sprocket when the inner wire tension is released. As with other indexing derailleurs, the inner wire tension should be set as tight as possible with good shifting. However, the symptoms of a too-tight setting are different, which for "Low-Normal" systems are when the derailleur shifts outward slowly, or a there is a rattle from the upper pulley being aligned too far outward. Look underneath the rear sprocket at the alignment of the upper pulley when there is a rattle to see if this is the cause.

1. Shift chain to middle ring in front and innermost sprocket in back. 2. Pedal and shift lever one position. 3. Pedal and turn barrel adjuster counter-clockwise to tighten inner wire tension until chain begins

to shift outward. 4. Turn barrel adjuster clockwise 1/4 turn until chain runs smoothly on second cog. 5. Shift outward one sprocket at a time trying each gear. Turn barrel adjuster 1/4 turn clockwise if

too tight symptoms occur. 6. Shift to all other normal gear combinations and test adjustment.

NOTE: The indexing procedure here assumes that there are no unusual problems, such as bent derailleurs, bent derailleur hangers or excess inner wire friction from dirt in the housing. Additionally, manufacturers design shift levers and drive train components to work within their system. Mixing brands within the drive train may lead to poor shifting. This is referred to as a compatibility problem.

FRONT DERAILLEUR ADJUSTMENTS

Useful Tools and Supplies Hex wrenches as needed. Screwdriver (#2 Phillips or straight blade) Light liquid lubricant Derailleur cable inner wire and housing as needed Rags

This article will discuss the basic adjustment of the front derailleur.

This article assumes the derailleur is compatible with the shifting system and is not extremely worn out.

Service Procedures The front derailleur simply shoves the chain off one front chain ring and onto another ring. The cage surrounding the chain is pulled in one direction by the inner wire. A spring in the derailleur returns the cage to the other direction when the inner wire is relaxed. A properly adjusted front derailleur should shift the chain between the front chainrings but will not throw the chain off the rings. The basic adjustments for the front derailleur are the height, rotation, limit screws and inner wire tension (index setting).It is generally a good idea to lubricate the pivot point of the front derailleur with a light lubricant. The cable inner wires should also be lubricated. If you have loosen the inner wire pinch bolt, lubricate those threads as well. When tightening this pinch bolt, secure to approximately 30-40 inch-pounds. This is about 10 pounds of effort hold a wrench 3 inches from the bolt.

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Front Derailleur HeightBefore checking limit screw adjustments, check the derailleur positioning. If the derailleur cage is too far above the large chainring, it is more likely to shift poorly. If the derailleur is too low, it may scrape against the chainrings or jam the chain when shifting.Some front derailleur models do not have height or rotation adjustments. These models mount on a plate and both height and rotation settings are pre-set. Additionally, some bikes have a bracket commonly referred to as a "braze-on" for front derailleur mounting. This bracket will allow limited height and rotational settings.

1. Inspect height alignment of front derailleur. The outer cage plate must be positioned over the largest chainring when viewing height. Simply grab the exposed front derailleur inner wire until outer cage plate is directly over outer chainring teeth. Use care to not shift the derailleur cage past this point. Note height and direction of change needed. It is then necessary to relax the cable to loosen the mounting bolt and raise or lower the height as needed.

2. The gap between the teeth of the outer chainring and lower edge of the outer cage plate should be 1-2mm, about the thickness of a penny. Using a penny or a dime as a feeler gauge fit it between the chainring teeth and the cage plate. It should just fit between the teeth and plate.

3. To lower cage, release inner wire tension completely by shifting to innermost chainring. Note angle of outer cage plate relative to chainring.

4. Front derailleur clamps typically leave a mark on the frame, which is useful as a reference when changing height. Loosen derailleur clamp bolt, change derailleur height, and return cage to same rotation relative to chainring. Tighten clamp bolt. Move outer cage plate over outer chainring, and check height again. Repeat this process until cage plate height is 1-2mm above outer chainring.

Front Derailleur Rotational AngleThe front derailleur cage should be approximately parallel to the chain. If the derailleur cage is rotated too far from this position, it will shift poorly. If the derailleur mount is a clamp type, its rotation can be changed. Generally, the outer cage of the front derailleur should be aligned to the chain. The middle image below shows adequate alignment.

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1. Shift chain to outermost chainring and outermost rear sprocket. 2. Sight chain from directly above chainrings. Consider the chain as representing a straight line. Compare

this line to outer derailleur cage plate. Outer cage plate and chain should be parallel. Keeping the cage and chain parallel will minimize the risk of the chain jumping off the outermost ring. If cage is not parallel, there will be a relatively large gap at either the back or the front end of the cage, and the chain may over shift.

3. If derailleur cage needs to be rotated, note direction of desired rotation. 4. Release inner wire tension by shifting to the innermost chainring. 5. Many clamps leave a slight marking on the frame. Use this scarring as a reference when changing

height. It is also possible to use a pencil to make two reference marks on the frame, one for height and a second, vertical mark, to reference rotation. Use the marks to avoid inadvertently changing height.

6. Loosen clamp bolt and slightly rotate in correct direction. Use care not to change height. Tighten derailleur clamp bolt.

7. Shift to outer chainring and observe rotation alignment. Repeat adjustment if necessary.

NOTE: Some front derailleur models do not have height or rotation adjustments. These models mount on a plate and both height and rotation settings are pre-set. Additionally, some bikes have a bracket commonly referred to as a "braze-on" for front derailleur mounting. This bracket will allow limited height and rotational settings.

Front Derailleur Limit Screw SettingsLimit screws stop the inward and outward travel of the front derailleur cage. Limit screws are marked "L" and "H". The L-screw will stop the motion of the derailleur toward the smallest chainring. The H-screw will stop the motion of the derailleur toward the largest chainring.If the limit screws lack any marking, you will need to determine which are the "H" and "L" by testing. Begin with the chain on the smallest cog. Relax the cable tension completely using the cable barrel adjuster. Place a hand on the derailleur body to feel for any lateral motion, and select one screw to turn one full turn clockwise and then counter-clockwise. If you felt motion in the derailleur, this is the "L" screw. If there was no motion, do the same test with the other limit screw. You should consider marking the "L" screw permanently. The other screw by default is the "H" screw.Although the limit screws will stop the derailleur, it is the inner wire and derailleur spring that make the derailleur move. If the inner wire has too much tension, the derailleur will not rest on the L-screw stop. If the inner wire tension were to change, the derailleur inner limit would also change, possibly causing the chain to fall off the rings.

Front Derailleur - Adjusting L-screwThe L-screw controls the inward most travel of the front derailleur. Set adequately, it allows the chain to shift to the smallest ring, but not beyond so it falls off.

1. Shift chain to innermost rear sprocket and innermost front chainring. Inspect derailleur for marking indicating "L" screw.

2. Check inner wire tension. It should be fairly loose at this time. If inner wire is taut, turn barrel adjuster

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clockwise into housing. The barrel adjuster is typically located where the cable housing enters the shift lever. If barrel adjuster is already fully turned into housing, loosen inner wire pinch bolt, slacken inner wire and retighten bolt.

3. Sight gap between inner chain plate and inner cage plate. Only a small gap should be visible, about 1/16" or 1mm, about the thickness of a dime.

4. Pedal bike slowly and continue to sight gap. Set clearance at tightest point in chainring rotation. Adjust L-screw so there is a small gap between inner cage and inner chain plate. Pedal bike and check that chain is not rubbing cage as chainrings turn.

1. If there is no gap and chain is rubbing cage, loosen L-limit screw 1/8 turn (counter-clockwise). Inspect for gap again and repeat until slight gap appears.2. If the gap appears larger than 1mm at its widest point, tighten the L-screw, in small increments, until the gap closes.

5. Test the shift by shifting chain to next chainring then shift back to the innermost ring. Do not use the shift lever. Pull on the inner wire to shift the derailleur. Using the lever may confuse limit screw issues with cable tension issues. If chain shifts quickly, limit screw setting is adequate.

6. If the shifting appears is slow (requires more than one pedal revolution to initiate shift), turn L-limit counter-clockwise 1/8 turn and repeat test. Repeat 1/8-turn increments until shifting is adequate. The gap will open wider than the 1mm target, but will still be as small as possible with adequate shifting.

7. If chain is shifting beyond the inner ring and falls off the chainring, gap may be too large or cage alignment may be off. Tighten L-screw 1/8 turn and check shift again. If chain ends up rubbing inner cage of derailleur, yet still drops off inner ring when shifting, other problems such as chain line or derailleur rotation exist.

Front Derailleur- Adjusting H-screwThe outward travel of the front derailleur is stopped by the H-screw. When viewing the H-limit adjustment, make sure there is enough tension on the inner wire by either keeping extra pressure on the lever, or by pulling the exposed inner wire taut by hand. Use a rag to protect your hand if pulling the inner wire. After the H-screw is adjusted the inner wire should be re-tensioned to assure proper shifting.

1. Shift to outermost sprocket in rear and outermost front chainring. Inspect derailleur for mark indicating H-screw.

2. Pull inner wire with hand to increase tension to insure derailleur is against H-screw. 3. Maintain full pressure on inner wire and check gap between chain and outer cage plate. Only a small

gap should be visible, about 1/16" or 1mm. Pedal bike slowly and continue to sight gap. Set clearance at tightest point in chainring rotation.

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A. If chain is rubbing cage, loosen H-screw 1/8 turn and pull fully on inner wire. Check gap again.B. If chain is not rubbing, tighten H-screw repeatedly until chain is 1mm

4. Test shift to the large ring. Shift derailleur from next to largest to largest ring using hand pressure on inner wire rather than shift lever. If shifting is slow, loosen H-limit screw slightly and repeat test. If chain shifts off the outside of the large chainring, the outer-limit is set too loose. Tighten H-screw limit and test shift again.

Front Derailleur- Adjusting Indexing (Three Chainring Bikes)Some front derailleur systems have an index setting. If the shift lever has three distinctive stops or clicks, it is indexing. If the front shift lever is friction, there is no index setting. If the front shift lever has multiple clicks, such as some twist grip style shifters, it is shifted similar to friction levers. Set indexing only after completing all adjustment above.

1. Shift chain to middle chainring in the front and innermost rear sprocket. 2. View gap between inner cage plate and chain. Gap should be as small as possible without rubbing

chain.

3. To reduce gap, increase inner wire tension by turning barrel adjuster counter-clockwise. Adjusting barrel may be on frame or on shift lever. Check gap again.

4. If chain is rubbing cage, turn barrel adjuster clockwise, or inward toward shifter body.

If barrel adjuster is all the way in or out and no adjustment is possible, reset inner wire tension. Shift to innermost chainring and loosen inner wire pinch bolt. Pull wire gently with fourth-hand tool and tighten pinch bolt. Begin adjustment of inner wire tension as above.

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5. Test shift of front derailleur to all three front chain rings. If the derailleur rubs in the largest front chainring, double check H-limit screw and inner wire tension, which may be too loose. If chain is slow to shift to smallest chainring, double check L-limit screw and inner wire tension, which may be too tight.

Front Derailleur Performance The front derailleur should shift the chain between chainrings without throwing the chain off the extreme outer and inner rings. It is possible that the front derailleur will rub the chain slightly even on properly adjusted bikes. This is likely on some bikes when riding in the largest sprocket in front and the smallest cog in back. As the bike is pedaled with force the frame flexes and moves the chainrings side to side, which cause an intermittent rubbing noise. Loosening the H-limit would move the front cage out more, and may stop the rubbing, but it may also cause the chain to shift over the largest ring and come off. If all aspects of front derailleur adjustments are correct on this bike, the rider is simply exceeding the engineering and design capabilities of the machine.

Regular Bike Maintenance1. Check Tire Pressure

Why? Riding on under-inflated tires can cause flats and damage your wheels. And pumping up tires is a lot easier than fixing bent wheels.How? It's hard to tell with your thumb if a tire is under-inflated, especially on narrower, higher pressure tires. Instead, use a pressure gauge or a floor pump with one built-in.What if there's a problem? It's good to know how to change a tube yourself, and a lot of you reading this probably already do. But if you're not sure, have a mechanic at your local shop give you a quick lesson. Rear wheels can be a little tricky to remove and install because of the chain & derailleurs. Mechanic's Tip Don't just throw a new tube into the tire without finding out what caused the flat - if the sharpie is still stuck in your tire, it will be happy to flat yet another tube. Safety Pointer Under-inflated or over-inflated tires can both cause accidents, though it's more common with under-inflation.

2. Check Your Chain LubeWhy? Riding with a dry chain wears the chain's moving parts out faster. This, in turn, wears out everything else on your drivetrain faster: cassette, chainrings, even the little pulleys on your derailleur.How? Before throwing a leg over the bike, back-pedal a half-revolution and listen for squeaking from your chain. If it's squeaky, looks dry, or even if it's just been a while since you lubed it last, take a second to apply some fresh oil to the chain.What if there's a problem? Steady a drip bottle of chain lube so that it's just above the chain, then backpedal through three or four revolutions while gently squeezing the lube out onto the top, not the sides, of the chain. If you don't want to get messy, a local shop will usually do it for a dollar or two. They can also tell you what oil to use in your locale.Mechanic's Tip Every climate has its own best chain lube. Seattlites might want something not too far removed from motor oil, while we Coloradoans favor fairly thin lubricants that don't attract too much dust. But WD-40, Liquid Wrench and similar "penetrants" are never a good idea.Safety Pointer Don't use aerosols, as the overspray can get on the rim and interfere with your rear brake.

3. Check Your BrakesWhy? Because people with bad brakes lead shorter, more painful lives.How? Before you start rolling, squeeze each brake a couple times to make sure they're working. Squeeze them again lightly as you start rolling to feel for uneven braking due to wheel damage, or the change in braking vibration that can mean your brakes are rubbing the tire rather than the metallic

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braking surface of the rim.Mechanic's Tip This is especially important if you frequently take the wheels off for transportation or storage -- it's common to forget to hook up the brakes again.What if there's a problem? It may be as simple as taking up a little slack in the brake cable with a barrel adjuster or as complicated as a loose or broken part, but. . .Safety Pointer . . .these are your brakes we're talking about, so if you don't know what you're doing, take it to a shop.

4. Feel for Loose PartsWhy? Some loose parts will cause things to wear out faster, while others can cause crashes. Either reason is good enough for me.How? As you mount and push off, feel for anything unusual. The force of your weight on the bike and the first couple pedal strokes will usually make serious problems like loose wheels, saddles, handlebars or accessories apparent with a clunking sensation.What if there's a problem? Depends on what it is. If you can find it and fix it, great; if not, you shouldn't ride until you know what's causing any big clunk.Mechanic's Tip Again, people who frequently remove wheels for transportation or storage are most likely to encounter forgotten quick release levers.Safety Pointer Novice cyclists are often mystified by quick-release levers (if you're not certain that you're doing it right, ask someone who knows). But any significant clunking sensation means something's about to fall off or fall apart, and that's never safe.

5. Listen for Unusual NoisesWhy? Because bikes are so quiet, you can detect problems early with a good ear. Early detection means less expensive repairs and safer riding.How? As you start out on your ride, listen for unusual sounds of scraping, rattling, rubbing, or creaking.What if there's a problem? Stop and see if you can figure it out. If you can't, it might not always be necessary to scrap the ride. Little noises can be really hard to track down, and if there aren't any other symptoms, it might not require immediate attention.Mechanic's Tip Pay attention to rhythm. Noises that start & stop with your pedaling are usually symptoms of something in the drivetrain or parts of the bike that bear your weight. Wheel & brake noises will get faster as the bike accelerates, and continue whether or not you're pedaling.Safety Pointer Noises relating to wheel rotation are always worth finding before you ride anywhere, since they often indicate unsafe conditions in your brakes, tires or wheels. On the other hand, creaking sounds that seem to occur when you shift your weight around on the bike can be as benign as a stem or seatpost that needs lubrication, or as serious as a small crack developing somewhere important. Take it to a mechanic if the creaking gets louder or fails to go away.

Tips There are two steps to fixing your bike: diagnosis, and repair. Learning to recognize when something's

wrong is the first step; learning to figure out what exactly it is is the second. Neither of these require tools.

If you want to learn more about taking care of your bike yourself, one good way to do it is to pay a shop to work on your bike in the winter, when the mechanics will have a little more time to answer questions and show you how to do some things yourself.

Warnings Bikes are pretty simple machines, but if you really don't know what you're doing, you can create unsafe

conditions on yours without realizing it. Get a good book, learn from a shop or a friend, or leave it to the professionals if you have reason to doubt your mechanical abilities.

Know your limitations. While there's a lot on a bike that just about anyone can fix, other things are surprisingly complicated or confusing. "Truing" or straightening wheels, in particular, is something that nearly all novice mechanics will do badly unless they have help or instruction.

After you've worked on your bike, your first ride should be a cautious test ride in a safe place. If you forgot to do something important, you don't want to find out about it in traffic.

Things You'll Need For diagnosis, you only need an alert mind and your senses. To keep your bike running smoothly from day to day, you'll need a decent pump with a guage, and

some chain lube

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It's nice to have a pump, spare tube, tire levers and a patch kit with you if you get a flat. Otherwise you're walking or depending on the kindness of strangers.

Once you start to actually work on your bike, you'll need: appropriate box/open wrenches - adjustables and pliers will ruin your bike's nuts & bolts

"Allen wrenches" or hex wrenches. These are male hexagonal tools, usually L-shaped, that fit the female hexagonal sockets on many bike parts.

All manner of special and expensive tools, as your repairs get more involved. You can get a kit, but you're usually better off getting them a la carte as you need them.

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