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Bike Maintenance
Use this tip sheet to learn about basic up-keep of your bicycle.
General Mechanic Skills
- Pedals, stem bolts or waterbottle bolts, grease everything before installing
- Boat trailer bearing grease is inexpensive and waterproof
- Grease all flats on bolt heads that will be up against other metal pieces
- Bearings should be repacked (cleaned and re-greased) about yearly
- Races are smooth, precision surfaces on which bearings roll; clean then re-grease
- Bearings are easily destroyed if you don't understand how to adjust them properly
- Grease crank bolts, never grease bottom bracket tapers; you may damage crankarms
- Grease chainring bolts and surfaces where chainrings attach to crankarm
- Clean out pedal threads with a rag, bristle brush or degreaser
- Take care not to lay bike down on its derailleurs; you might damage them
- Remove dirt or lube related buildup with a rag and flathead screwdriver
- Inspect derailleur cables and housing for cracking and fraying; replace if necessary
- Bearings in your headset need annual re-packing; more often if you ride in the rain
- Clean bearing surfaces, re-grease and replace bearings; use grease to hold them in
- Clean old grease out with rag, inspect bearing for wear and replace if necessary
- Use sand paper to smooth out inside of seat tube to avoid scratching seatpost
- Apply liberal coating of grease to top three inches inside seat tube
- Grease help keep water out of frame tubes and allow easy removal of seatpost
- Hubs roll on bearings like your headset; regular service is necessary
- Turn axle by hand to check hub status; if it feels loose and gritty, clean and re-grease
- Riding on hubs with no grease can destroy bearings and races
- Creaks are usually caused by metal shifting on metal under stress, like pedaling
- Every place two pieces of metal are touching, there should be grease between them
- Locate noise and silence by re-assembling with a liberal coating of grease
- Most parts on a bike do not need to be as tight as humanly possible, just snug
- Turn bolt until threads are buried then a quarter turn to tight
Causes of Flats
- Glass, thorns, nails, staples, screws; anything sharp can cause a flat
- These result in slow leaks that can take up to 48 hours to go completely flat
- Usually easily repaired with patch kit; not normally associated with severe tire damage
- Compression of the tube between your rim and a hard surface
- Known as 'snakebites,' these are dramatic, audible flats that deflate quickly
- Hard to repair with patches; replace tube or use oval patches; rim damage possible
- Improperly adjusted brakes can rub through tire and cause tube to blow out of tire
- Maintaining proper tire pressure helps prevent flats and maximizes rolling efficiency
- Worn tires leave less rubber between the tube and the road, decreasing flat protection
- Spokes and sharp spots on the inside wall of the rim can cause flats
- Recurring flats are usually caused by sharp metal on the rim or part of a spoke
- Use a file or sandpaper to buff off the sharp spot and remove any burrs
- Carefully studying where the hole in the tube will allow you to find its cause
- Make sure that you keep the wheel, tube and tire in the same orientation
- Flats may be caused by imperfections in the tube; these may be impossible to detect
Tire Pressure
- Tires naturally lose air over time; if you don't pump them up, they will go flat
- Floor pumps work best at home; they move the most air and are easy to use
- Skinny tires need air almost daily; fat tires need air weekly
- Hand pumps work well in emergency situations; convenience over performance
- CO2 is fast and easy but can be tricky; carry a pump as backup
- Long skinny pumps for high-pressure skinny tires; short fat pumps for fat tires
- Know your valves, presta or schraeder; carry an adapter just in case
- Both types of valves can be damaged; some tire sealants can clog valves
- Presta valves tend to hold air better than schraeder valves
- Recommended pressure is printed on tires; be careful if you go higher or lower
- Mountain bike commuters frequently inflate tires to 80 psi for faster going
- Tandem riders can inflate hybrid tires to 90 psi or more
Patching Tubes
- Pump tube with air; listen and feel around the tube for the leak
- Mark hole with chalk or hold under your thumb
- Use the sandpaper or another abrasive to rough up tube around hole
- Apply glue to the size of a quarter, centered around the hole
- Allow two to three minutes for glue to set; glue will turn cloudy
- Make sure that the glue area is slightly larger than the patch
- Remove patch with plastic still attached; do not peel plastic off of patch
- Place sticky, non-plastic side down, centered over hole
- Slide it around in a small circle to ensure even distribution of glue
- Hold patch firmly between thumb and forefinger for about three minutes
- Time taken now will ensure that your patch will hold later down the road
- If at home, place tube flat between two books and place heavy object on top
Fix a Flat
- Front: undo brake then wheel quick release and remove
- Rear: shift into smallest cog in rear, undo brake then hub quick release; remove
- Rear: set bike upside down on handlebars and seat before opening hub quick release
- Remove remaining air by depressing valve
- Schraeder is larger, spring loaded valve and must be depressed; car style valve
- Presta is all-metal, air sprung narrow valve; unscrew then press
- Using tire levers, unseat one side of tire; start away from valve stem
- For tight rim/tire combinations, multiple tire levers are needed; do not use metal levers
- Many mountain and hybrid bikes tires will come off by hand; practice at home
- Remove tube from tire; avoid valve damage by starting away from valve
- Keep tube and tire in same relative position to each other to aid in finding puncture
- Inspect tube for hole; mark for patching or use your spare tube for replacement
- Feel inside of tire for cause of flat; use caution as cause may puncture your finger
- Remove thorn, glass, staple, nail or whatever caused your flat
- Inspect tire for damage caused by flat
- After repairing damaged tube or retrieving spare, inflate tube to give it round shape
- Fold back tire to allow access to valve hole; insert valve first then tube into tire
- For presta valve, screw valve closed and install valve nut loosely against rim
- Start reseating tire by hand at valve hole; work in both directions
- Push valve partially back through rim to insure proper seating of tire bead
- Visually inspect tire bead to insure proper tire seating on rim
- Inflate tire slowly, checking for bulges which might indicate improper bead seating on rim
- Deflate if bulge occurs; carefully re-inspect and reseat bead on rim
- Inflate to desired pressure
- Front: install wheel; tighten hub quick release and attach brakes; make sure it is straight
- Rear: install wheel by placing chain on top and bottom of small cog
- Rear: push pulley closest to you forward; drop hub down into frame and tighten
Brake Basics
- Road bikes have center-mount, side pull brakes
- Mountain, touring, cyclocross and hybrid bikes have cantilever mount brakes
- Linear, side pull cantilevers or vee brakes are the most common on new bikes
- Squeals and scrapes are the most common noises which can be fixed
- Brakes squeal from pads hitting the rim flat; toe in brake pads to stop noises
- Scraping means you need to either sand the metal out of the pads or replace them
- Brake pads should be replaced when you get down to about ¼" of pad left
- Properly toed in brakes wear at a slight angle; too much and they will wear faster
- Front brake pads last longer because the front brake is stronger
- Your brakes will hit sooner if you unscrew the barrel adjusters around the housing
- You can shorten the reach with a screw that points toward the other brake lever
- Your first lever adjustment should start with the barrel adjusters all the way in
- Find out how to use the brake cable quick release at the lever; this will aid in cleaning
- Inspect brake pads for wear or metal shards; sand pads to remove metal
- Sand pads to improve braking; heat from braking will glaze pads and reduce power
Front Derailleur Adjustment
- Set limits of how far the derailleur travels; turns clockwise decrease range
- 'H' screw limits how far derailleur can travel away from bike; 'L' towards bike
- Road and mountain front set screws are on different parts of the derailleur
- Looking down on derailleur, outside cage should be parallel with the chainrings
- Replace derailleurs with bent cages as shifting performance will be decreased
- Cage should line up about 3 mm above biggest chainring with derailleur extended
- Triple chainring derailleurs allow chain to drop lower for the smallest chainring
- Double chainring derailleurs have narrower cages and cannot be used on triples
- Triple derailleurs have special areas that help shift chain off of smallest chainring
- Based on cable routing on the bike, derailleurs are either top or bottom pull
- Derailleurs also have different clamp diameters for different frame tube sizes
- Top or bottom swing derailleurs are also available; check with a bike shop
- Mountain derailleurs have a different arc along the cage for smaller chainrings
- Road derailleurs have a wider arc to accommodate larger chainrings
- Mountain derailleurs have a wider margin of error to account for mud and dirt
Rear Derailleur Adjustment
- Set limits of how far the derailleur travels; turns clockwise decrease range
- 'H' screw (lower) sets how far the derailleur travels away from wheel; for small cog
- 'L' screw (upper) sets how far the derailleur travels towards wheel; for big cog
- Where the housing and cable enter derailleur, plastic piece is threaded for adjustment
- Can be screwed by hand for quick adjustments; affects cable tension for shifting
- If installing new cable, start with barrel adjuster all the way clockwise
- Black plastic housing protects cable and allows it to turn corners
- Too little will affect shifting adversely; leave enough for a gradual sweeping bend
- Inspect regularly for cracks and other damage; replace yearly with cables
- Part of frame that derailleur threads into; replaceable derailleur hangers are common
- Hanger must be vertical and parallel to frame to allow proper derailleur alignment
- Bike shops have a tool that can straighten derailleur hangers unless it's replaceable
- Grab lower cage and gently move side to side; replace if there is excessive play
- Main cause of worn derailleur is main pivot that bolts to frame
- Derailleur Linkage may also weaken or loosen adversely affecting shifting accuracy
- If chain shifts into spokes, turn 'L' set screw in half turn increments until fixed
- If chain shifts onto frame, turn 'H' set screw in half turn increments until fixed
- A broken chain can tear the derailleur off the bike and destroy wheel or frame
Packing Your Bike
- 4mm, 5mm and 6mm hex wrenches and pump
- Pedal wrench (open ended 15mm wrench might work)
- Small blade or pocket knife to cut cardboard and open box on arrival
- Obtain a bike box and plastic fork protector from a local bike shop
- Get extra cardboard boxes to reinforce inside of box and protect the bike
- Packing tape, sandwich bag, rag, bubble wrap or newspaper (optional)
- Remove pedals, front wheel and quick release, stem from steerer tube and seatpost
- Insert bike in box; turn handlebars to allow them to fit; stick seatpost near rear wheel
- Insert front wheel in front of and just above cranks; cranks should be horizontal
- Insert fork protector into fork, wrap frame in bubble wrap or newspaper (optional)
- Fold a piece of cardboard and place it inside of box, below and in front of fork
- Place a piece of cardboard between wheel and frame, wheel and box
- Put pedals and front quick release in sandwich bag with pedal wrench and rag
- Pack tools and pedal bag together in easily accessible bag or pannier
- Twist tie a seatpost rail to rear wheel or rack so it can't fall out
- Holes can magically appear in the box during flight/shipping allowing things to fall out
- Avoid storing helmet or small items in the box with the bike; panniers add protection
- Sealed items may explode during air transport, including tubes and lube
Tools for the Road
- Take tools for work that you can perform
- Try to fix things if you are sure that you can improve how they work
- Do not depend on others for your mechanical needs
- Maintain your bike or let a bike shop do it for you; twice a year for heavy use
- Catch problems before they happen on the road with regular inspections
- If you have hard to find items on your bike, stock up when you can
- If you are going to be far from civilization, prepare with extra tools or parts
- For short rides, you might not carry any tools if you don't mind walking
- Urban areas may have more glass in the roadway; bring patches and a tube
- Tire levers, tube, pump and patch kit for flats
- Allen wrenches, chain tool and screwdriver for mechanicals
- Understand which tools are needed for your bike; tools don't fix things, people do
- If you carry a phone for emergencies, make sure you have reception on your ride
- First aid can be an important part of a tool kit; know how to use it
- Stop to help others but only attempt to fix what you know you can