body. Learn to tune into your bicycle, so that you automatically listen to it and watch it as you cycle along. The better you ride, the more aware you will become of the bicycle's mechanical condition, and the more you will tune and maintain it as a matter of course. Hearing
Any bicycle produces a constant melody of sounds, whirrs, clicks, and soft hisses that form a rhythmic pattern when all is working well. Listen for any unusual noises, and when they arise, try to track down the source immediately: if you hear a rapid clicking, then pause in your pedalling for a moment. If the noise persists, it is most likely in the wheels. Stop and spin each wheel individually to locate the cause.
Touch
Your sense of touch is always vital. If the bike feels uneasy as you bank through a corner or swoop down a hill, then trust your senses. Stop and check the tyre pressures. If they are OK, check that the wheels are firmly mounted and
properly aligned. Or you might be climbing up a hill or up a short incline and standing out of the saddle, and suddenly you can feel a click and an odd bump on the pedal downstoke. The click might be a chainring bending under the pressure and rubbing against a derailleur cage. The bump is a clue that the crank or the pedal might be coming loose.
Vision
Your eyes, like your ears, will develop a natural sense of order for the bicycle as you become accustomed to the way it works. If you happen to watch the chain and rear derailleur working, you might notice if the derailleur arm suddenly moves to and fro, as the chain passes over the pulleys. The cause of this is probably a stiff link in the chain. Or if the chain rises slightly as it feeds onto part of the chainring, a chaintooth may be chipped or bent. You won't consciously look for the things which are wrong, but if you keep a constant eye, ear and hand on the bike, you will notice right away when something is incorrect and not functioning properly.
CHAIN WEAR
Test the chain for wear by lifting it onto the large chainring. If one of the chain- wheel teeth is fully exposed, it is worn out. Alternatively, measure, pin-to-pin, a 30.5 cm (12-in) length of chain. If it measures 30.8 cm (2%8 in) or more,
the chain is worn. Replace the chain, chainrings, and the sprockets at the same time; a new chain will perform badly on
worn sprockets. If your bike has specific
chainring/sprocket combinations, then you can retain those that are not worn.
CHAINTEETH
Check that the chainrings are true, and without any side-to-side wobble. Check also that none of the teeth are chipped or bent. Very worn chainteeth look like a shark's fin or a series of little waves — and their replacement is well overdue.
THIRTY MINUTE SERVICE II
THE HEADSET
Check the headset bearings by firmly engaging the front brake and push the bike back and forth. A click-clunk sound indicates loose headset bearings, or a loose brake mounting bolt. Lift the
front wheel and lightly rotate the handlebars. Any roughness
indicates the bearings are too tight and/or need re-greasing.
LOOSE CRANKS
Creaking noises are often caused by loose cranks. To test them, place the cranks horizontally, and press down hard on both pedals
at once. Rotate the cranks 180° and then press the pedals again.
If the crank moves, the crank mounting bolts need tightening.
Check the cranks frequently on new bikes.
PEDALS AND CRANK
Grasp the pedal and crank firmly, and push the pedal back and forth. Clicking
sounds indicate that the bearings are loose and need some adjustment. Then
spin the pedals. Grinding and sticking
indicates the bearings may be too tight. If
you use toe clips, check them for splits or
cracks. Check that the straps are in good condition, and do not have grooves which could allow the buckles to slip.
BEARINGS
The hubs, bottom bracket, pedals, and freewheel of a bike all use ball bearings to reduce friction between the moving parts, for example between a wheel hub and an axle. Some bearing mechanisms are fixed, so they can't be adjusted. Adjustable bearings have a race or cup
which is fixed in place, and a moveable cone or cup held in place with a locknut or lockring. A basic technique for adjusting the bearing is to slacken the locknut or lockring and hand- turn the adjustable cone or cup flush against the bearings. Reverse it Y8 to h turn. Hold it in place, lightly retightening the locknut or lockring. Test the adjustment, which should be slightly loose, and should give a very light click when pushed back and forth. Firmly tightening up the locknut or lockring will draw the bearing into perfect adjustment – but do always check: hub bearings will tighten slightly when the wheel is fastened to the frame.
TRACKING
An important first step when looking at the wheels on your bike
is to check the tracking— the alignment of the wheels. With the bike resting upside down on its saddle, sit behind one of the wheels so that, at eye level, you can see'yhether the wheels are in line.
CLEANING AND LUBRICATING HUBS
When dismantling hubs, always ensure that you count the bearings as they are removed. Clean all parts in a biodegradable solvent and dry. Pack cups with grease and press the ball bearings into the grease.
CYCLE MAINTENANCE