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Aside from the whoosh of the tires on the road, and the clicking of the freewheel, a bicycle should be silent.
If your bike makes other noises, it is a sign of a problem. Many of these problems can be cured easily at an early stage, just by tightening up a nut or bolt...but if you ignore the noise, it may result in serious damage to parts of your bike, and you may find yourself stranded or even injured when the problem gets more serious! Most bicycle noises have some sort of regular repeating pattern. Identifying this pattern is the first step toward locating the source of the problem. If the noise occurs:
If your bike makes a regular noise or vibration when you apply the brakes, it is most likely due to an imperfection in the braking surfaces on the sides of the rim.
In the case of new bicycles, (or new wheels) a very slight amount of irregularity is sometimes the result of unevenness of the braking surface at the seam where the rim is connected after it is rolled into a hoop. In minor cases, this problem should go away after a couple of hundred miles/km of riding, as part of the normal breaking-in process. More sever cases indicate a defective rim, and warranty replacement of the wheel may be indicated.
In the case where this sort of pulsation develops in an existing bike that had been OK, it often indicates a rim that has been damaged by impact with a pothole, stone or other road hazard. Sometimes this sort of "blip" can be repaired by the judicious use of a hammer or a special pair of pliers made for the purpose. In most cases, unfortunately, a new rim/wheel is the only real solution.
The tire is supposed to protect the rim from this sort of damage. Rim damage is usually caused by neglecting to keep your tires properly inflated, or by riding too narrow a tire for the conditions. With more experience, a cyclist becomes more alert to road-surface hazards and can safely ride narrower tires.
If you have a regular rubbing sound when coasting, do not ride the bike until you have checked it out and at least determined the cause of the problem; some of these problems may only rob efficiency, but if your tire is rubbing, you can destroy the tire surprisingly quickly!
Lift up each end of the bike in turn, and spin each wheel forward, looking, listening and feeling to find where it is rubbing.
If the tire is rubbing on the frame, it indicates that:
Never ride a bike while the tire is rubbing!
If the rim is rubbing on a brake shoe, it indicates that:
It is common for this problem to develop after removal/re-installation of a wheel, if the wheel is not properly aligned in the frame/fork. Sometimes people install the wheel crookedly, then try to compensate by misadjusting the brake to match the off-center rim. Don't do this!
The best way to check that the front wheel is installed correctly is to place a finger of each hand between the tire and the fork blade. If you use the same finger of each hand, (and don't have mis-matched hands) you can tell by the feel if the tire is closer to one fork blade than to the other. If it is off center, loosen the quick-release or axle nuts, re-center the wheel, and re-secure it.
An off-center rim may be the result of poor installation, or may result from a bent axle, a bent fork, or an improperly dished wheel. Once you're sure that the wheel is properly centered, then you can adjust the centering of the brakes, if it is needed.
If the wheel is slightly out of true, it may be possible to do a temporary fix by changing the wheel alignment slightly, but the real solution is to true or replace the wheel.
If there is a rubbing/clicking sound when you are riding, but you can't get it to happen when you lift the bike and spin the wheels off the ground, your problem is most likely related to loose spokes. In some cases, the spokes of an under-tensioned wheel will audibly rub against one another where they cross. This will only happen when the bike is carrying the weight of a rider. You also may feel the bicycle lurch slightly to the side as the loose spokes get to the bottom of the wheel and lose control of the rim. Try squeezing pairs of spokes together to see if they make the same sound you hear when riding. Loose spokes are prone to break, and also often result from rim damage.
If the wheel-related rubbing sound only occurs when the bike is in low gear while coasting, it is most likely caused by the chain rubbing on the spoke protector. This usually indicates that the spoke protector is broken or bent.
Noises once-per-wheel-revolution that only occur when you are pedaling are most often related to the freewheel or Freehub. The freewheel or Freehub bearings may be loose, or the cassette may be loose on the Freehub body.
See if you can wiggle the sprockets back and forth. There should be little or no lateral play.
If the freewheel/Freehub bearings are loose, it is sometimes possible to tighten them, see my Freewheels Article.
If the sprocket cassette is loose on the Freehub body, you may be missing a spacer, or you may be trying to use a cassette that includes an 11 tooth sprocket on a Freehub body that was not intended to accommodate an 11 tooth sprocket. See my Shimano Cassettes article for details on this.
Most wheelbuilders lace the trailing spokes on the inside of the hub flange. In some very rare cases, wheels laced the opposite direction may lead to mysterious derailer/spoke rub only in the lowest gear and only when pedaling hard. This is due to the trailing spokes being tightened by the drive torque, and pulling the laced crossing point outward.
This is quite rare, and mostly only occurs with wheels that have insufficient tension to start with, and mis-aligned derailers/derailer hangers.
Clicks, creaks and clunks that happen once or twice per pedal revolution may result from quite a number of different sources, so there are a lot of things to check:
The threads of the bolt (or nut), and the underside of the bolt (or nut) head (where it presses against the crank) should be lubricated with grease.
This is a surprisingly common, and frequently missed, casue of unwanted noises. Generally you should check the items above first, because they're easier to deal with. You can't reliably check the tightness of the bottom bracket mounting without removing the cranks, but sometimes you can diagnose it this way:
Then turn the cranks so that the right crank is alongside the seat tube and repeat this. Listen for a creak/click.
See my Derailer Adjustment Article.
The easiest way to fix this is to bend the problem area of the chain into a "Z" shape, with the bad joint on the diagonal part, then flex the chain back and forth. This will slightly spread the tight plates, and free up the link.
The easiest way to spot stiff/damaged links is to shift the bike into the small/small gear (the gear you should never actually ride in.) This gear has the chain at its slackest, and flexes it farther than any other gear, as it goes around the small rear sprocket and the derailer pulleys. Slowly backpedal while watching the chain as it feeds through the rear derailer, and you will usually be able to see the bad link jump.
This is most often caused by a "blip" or bulge in the rim, a wide spot caused by hitting a rock, pothole or other road hazard. Rim blips can sometimes be fixed by careful hammering or squeeing the rim with pliers.
Note, blips like this typically only affect a very short section of rim. If you have a longer "wide" part of the rim, it may be an indication that an old rim's braking surface is wearing thin from many miles of brake usage. Don't ride rims like this, they sometimes cause rapid, dangerous blowouts!
A slight irregularity is not unusual with brand new rims, because the area where the rim is joined at the seam is often slightly irregular. This type of irregularity usually "wears in" after a couple of hundred miles of usage, and does not necessarily constitute a "defect" (depending on the severity.)
See my Article On Caliper Brakes.
The headset should be adjusted so as to prevent this sort of play. It is easiest to check this with the bike stationary: Lock the front brake and push the bike forward and backward, observing to see if the headset is wiggling. Sometimes it helps to rest your fingers lightly against the upper and lower headset races in turn to see if you can feel one part moving against another.
The first thing to check is that the handlebar binder bolt is tight enough. The threads, and the underside of the head of this bolt should be lubricated with grease or oil; if they aren't, friction in the threads may prevent developing sufficient clamping force.
Some handlebars have a reinforcing sleeve on the central section, which also acts as a built-in shim to fit the bars to the stem clamp diameter. The main part of the handlebar may occasionally move within this sleeve. I've had some success using Loctite ® for this: drip some on the bar where it disappears into the sleeve, then use a compressed-air blast to force it into the gap. Let it cure overnight before riding.
It is also a good idea to remove the stem from the steerer from time to time, and apply a liberal coat of grease to the inside of the steerer. The expander/wedge and its bolt should also be greased. Avoid overtightening the expander/wedge bolt, as this can deform the steerer. If you have a threadless headset, this is not usually necessary.
Shift cables crepitating when the bars are turned?
Dry derailer pulley bearing? (squeals even after you have lubricated the chain and will probably be warm to the touch. Disassemble and grease.)
Something in your pocket?
I once did a lot of searching to find the source of a riding companion's mystery squeak, only to find it wasn't his bike at all, it was the knee brace he was wearing on one leg!
Rick Mason offered:
When you tighten a threaded fastener, you are working against two sorts of resistance:
If you lubricate the threads, and the pushing face of the nut or bolt head, more of your applied wrench torque goes toward actually tightening the fastener.
Lubricating the threads also reduces the risk of stripping the threads.
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