The art of bike maintenance: trouble shooting squeaks and creaks
15th June, 2010
This extract from The Ultimate Guide to Bicycle Maintenance will help you identify the source of, and fix, nasty noises
While washing your bike check it over for dents and cracks and listen to the squeaks and creaks - they can tell you a lot...
Squeaks and creaks
A persistent noise from your bike can drive you mad. Squeaks, ticks and creaks can originate from many different places and they often need a careful process of elimination to find the source of the noise. Noises mean that there is something wrong so take them seriously.
The main cause of noise from your bike will be dry bearing surfaces or loose components.
The friction between surfaces, whether at the threads in your bottom bracket or the clamp on your handlebars, will not be solved by spraying copious amounts of penetrating lubricant into the component - and in particular, don't do this to your handlebars as they could slip and cause a nasty accident.
You can't always solve the problem simply by doing the bolts up a little tighter either, as they have recommended tightening torques and may simply need some anti-seize compound applying to them if they are titanium or aluminium. A persistent rubbing can be something as simple as a cable end hitting the cranks as you pedal, or something less obvious like a broken chain roller, a worn freewheel or a loose hub. All the components should be checked for cracks or splits, and anything that looks unusual should be checked out and replaced if necessary.
So what causes the noises in each component?
Very often, the saddle is the cause of pedalling-related noises. As the saddle is usually exposed to the muck off the rear wheel, it gets a lot of abuse and very little cleaning or care. The rails can start to wear out, resulting in a nasty noise as you push on the pedals and move your weight across the saddle. This can be relieved with a spray lube, but the saddle may need replacing. The rails can sometimes get corroded to the seatpost clamp, so check this out too.
How to detect where the noise is coming from
1. Stand on either pedal (you will need to be off the bike to do this) and apply some sideways pressure on the bottom bracket. If it clicks, the cranks or the bottom bracket may be the root of the noise.
2. Hold the front wheel in your knees and shake the bars from side to side - are the bars tight?
3. Apply the front brake and shake the bike - could the Aheadset be loose?
4. Grab the saddle with both hands and twist it a little - is it the saddle or the seat post?
5. Shake the wheels - are the hubs loose?
A dry seatpost will seize up pretty quickly. The residue and corrosion inside the seat tube can make a nasty creaking sound. Remove the seatpost and carefully clean inside the seat tube. Seriously corroded seat tubes will need reaming (cleaning out with a specialist cutting tool). Clean the seatpost with some wire wool and re-apply anti-seize grease before you replace it.
The clamp needs to be a perfect fit and suitably tight. Quick-release seatpost clamps can cause problems if they are not secured tightly enough. If you don't adjust your saddle height as you ride, you could change the quick-release clamp for an Allen key fitting.
This is the biggest cause of noise and to solve any problems you will have to strip it out and rebuild it on a regular basis.
The usual cause of noise is the square taper-type bottom bracket, which can cause all sorts of niggles if assembled incorrectly. Do not grease the taper as it simply forces the cranks on further and damages them. Clean the cranks with disc brake cleaner or a stronger degreaser and reassemble. Octalink-type bottom brackets need to be cleaned and a small amount of grease used to rebuild them. Always tighten to the correct torque setting and check for tightness regularly.
These can often ‘dry out' and start to click as a result. Remove them and clean the cranks thoroughly. Then rebuild the chainring bolts using an anti-seize compound.
Worn chainrings cause many more problems than you might think, and very often replacing the chain just makes them worse. Check the teeth for hook-shaped edges and missing teeth. A jumping chain can be dangerous - you'll get thrown forward as you pedal on the down stroke - so keep your chainrings in check.
This is often the cause of drivetrain noises. Check that the rollers of the chain are all intact and that there is no ‘stiff link', which may also cause the chain to jump or skip across the sprockets.
Another cause of drivetrain noises, if the cassette body is old and worn out it will sound terrible. To check this, hold the largest sprocket and rock it from side to side; if there is noticeable play then it may need replacing or tightening. Water and grit can ingress into the freewheel mechanism, which will eventually rust the internals.
Squeaks are usually associated with dry jockey wheel bushings. If the squeak stops when you stop pedalling, it will probably be caused by the pedals, bottom bracket or jockey wheels (the things that rotate as you pedal), which will need lubrication or replacement.
If left un-serviced for long periods, the bearings can deteriorate without you knowing it. Loose cones, especially in the rear wheel, can make a racket and will self-destruct pretty quickly - so get them re-adjusted as soon as possible.
Worn cleats are a problem for SPD users. Dry threads in the cranks can also cause creaking. This noise will usually occur when ‘standing' on the pedals. Remove the pedals and completely degrease the threads, then apply new grease and re-tighten.
Constant exposure to wet conditions will create problems with the adjustable elements of the bike (anything that clamps two components together). The water gets in and the residue will ‘dry out' and provide problems. Handlebars need to be secured in a smooth stem clamp, so check for burrs and clean out regularly.
Like the handlebars, problems with the stem are usually down to the clamp ‘drying out'. However, the star-fangled nut or a loose top cap can also creak. As with the handlebars, strip and rebuild and check your Aheadset too.
Dry bearings or broken races will make a very unpleasant creak as you pull on the handlebars. A strip and rebuild will usually eliminate the noise - re-pack the bearings with grease and fresh bearings if you can. Sometimes the crown race on the fork may need re-seating. A knocking sound can mean a loose Aheadset race and may mean the complete unit requires replacement.
Suspension - frame
The frame is usually the cause of noise on suspension bikes. ‘Clicking' is a regular fault, and is usually down to dry pivot points or worn DU bushings. Frames with large monocoque frame sections will amplify even the slightest clunk, so it may sound worse than it really is. Spring rear shocks can also rattle loose.
Suspension - fork
Again, any noises are usually down to worn or dried-out bushings. However, be aware of ‘hissing' in air forks, as this can mean a leaking seal, or scratching sounds in coil forks, as this can signify a broken spring. Both of these noises will be associated with a loss of performance. Knocking is also a sign of worn bushings, but can also mean that your Aheadset is loose.
Most brake noise is down to vibration. Disc brakes will require a regular full clean with a suitable alcohol-based rotor cleaner, and regular replacing of the pads. Check that all the calliper bolts are tight and that the rotor is secured correctly to the hub.
This usually happens when you pedal and could be caused by:
• the cable hitting the crank or your feet as you pedal
• a loose cassette sprocket
• pedal spindles
• the front mech hitting the inside of the righ hand crank - you will need to re-adjust it.
Rubbing or whirring from disc brakes
• Whirring usually means that the pads are worn too low.
• Check that the wheels are in straight.
• Re-centre the brakes.
• Check whether the rotor is buckled or damaged.
• Check the indexing - it should run straight on the sprocket
• If you have crashed recently, the mech hanger may well have been bent.
How to choose the right bike
There is a greater variety of bikes available now than ever before, ranging from as little as £100 up to over £1000. Here is some basic information on the six main varieties
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