What is idle in bicycles

Creak, crack & rattle ...

... and things that "hit" your bike on your bike.

by Sheldon "Shhhhhh ..." Brown

Translation by Arno Welzel, original at http://sheldonbrown.com/creaks.html.

Does your bike make strange noises when you ride it?

This article tries to help calm it down!

Aside from the rustle of the tires on the road and the click of the freewheel, a bike should be quiet.

If your bike is making a different noise, this is a sign of a problem. Many of these problems can be easily fixed at an early stage just by tightening a nut or bolt ... but ignoring the noise can result in serious damage to parts of your bike and you may find yourself helpless or even injured when the problem occurs gets more serious! Most of the sounds made by bicycles have a regular, repeating pattern. Identifying this pattern is the first step in finding the source of the problem.

Noises caused by an impeller, once per revolution of the wheel

When braking

If your bike makes a regular noise or vibration when you apply the brakes, it is most often due to an irregularity in the braking surface on the sides of the rim.

In the case of new bicycles (or new wheels), a slight imperfection is sometimes the result of an unevenness in the braking surface at the joint where the rim joined after being rolled into a circle. In harmless cases, the problem should go away as part of the normal break-in process after a few hundred kilometers of driving. In serious cases, this can indicate a defective rim and an exchange of the wheel is indicated as a warranty case.

In cases where this rhythmic disturbance develops on a bike that was previously fine, it is often a sign of a rim damaged by a pothole or other road damage. Sometimes such "dents" can be removed with the judicious use of a hammer or pliers for this purpose. Unfortunately, in most cases, a new rim or wheel is the only realistic solution.

The tire is intended to protect the rim from this type of damage. Rim damage is often caused by neglecting sufficient tire pressure or by driving tires that are too narrow for the respective conditions. With more experience, a cyclist pays more attention to road damage and can safely use narrower tires.

When idling

If you hear a regular grinding noise when idling, stop riding the bike until you have checked it and at least determined the cause of the problem; some of these problems only cost some performance, but if your tire grinds it can be destroyed surprisingly quickly!

Lift each end of the bike one at a time and let the respective wheel turn in the direction of travel while you look, listen and feel where it is dragging.

Grinding tires

If a tire rubs against the frame, it is a sign that:

  • the wheel is mounted at an angle, or
  • the wheel has a serious side flip, or
  • one of the fenders is misaligned, or
  • the tire has developed a bump and is about to fly off the rim.

Never ride a bike when a tire is dragging!

Grinding brakes

If the brake pad rubs against a brake, this is a sign that:

  • the wheel is mounted at an angle, or
  • the wheel has a lateral runout, or
  • the brake caliper / brake arms are not centered

This problem often arises after removing and re-installing a wheel when the wheel is not properly aligned in the fork or frame. Sometimes people mount the wheel at an angle and then try to compensate for this by incorrectly setting the brake so that it fits the off-center rim. Don't do that!

The best way to check that the front wheel is properly installed is to put one finger on each hand between the fork and the tire. If you use the same finger on each hand (and you don't have different hands) you can feel if the tire is closer to the fork blade on one side. If it is not centered, loosen the quick release or the axle nuts, center the wheel and secure it again.

An off-center rim can be the result of poor assembly, a bent axle, a bent fork, or an improperly centered wheel. Only when you are sure that the wheel is correctly centered can you adjust the center of the brakes, if necessary.

If an impeller is experiencing a slight lateral runout, a temporary solution may be to change the orientation slightly, but the real solution is to center or replace the impeller.

Abrasive spokes

If there's a grinding / cracking noise while you ride but you can't readjust it by lifting the bike and turning the wheels in the air, the problem is most likely due to loose spokes. In some cases the spokes of a wheel with insufficient tension rub against each other where they intersect. That only happens when the bike bears the rider's weight. You may also feel the bike lurch to one side as the loose spokes come down and lose control of the rim. Try to squeeze the spokes together in pairs to check whether they make the same noise as they do when driving. Loose spokes are prone to breakage and are often the result of rim damage.

Grinding of low gears

If the noises from the wheels only occur when the bike is coasting in a low gear, it is most likely due to the chain rubbing against the spoke guard. This is usually a sign that the spoke guard is broken or bent.

Noise from the wheels only when pedaling

Noises that occur once per wheel revolution and only then while you are pedaling are often caused by the freewheeling of the rear wheel hub. The freewheel bearings may be loose or the cassette may wobble on the freewheel body.

Check that you can move the pinions sideways. You should have minimal or no side play.

If the bearings in the freewheel or hub are loose, it is sometimes possible to tighten them. See also my article on freewheel hubs.

If the sprocket cassette is loose on the freewheel body, a spacer may be missing or you are trying to use a cassette with an 11-tooth sprocket on a freehub body that is not designed to accommodate 11-tooth sprockets. For details, see my article on cassette hubs.

Grinding of the rear derailleur / spokes in the "wrong" direction

Most wheel builders cross the following spokes on the inside of the hub flange. In very rare cases, wheels are spoked in the opposite way, which can lead to a mysterious dragging of the rear derailleur in the lowest gear if you pedal very hard. The reason for this is that the following spokes are tensioned by strong driving forces and thereby push the intersection points outwards.

This is very rare and usually only occurs on wheels with insufficient tension and incorrectly aligned derailleurs or derailleurs.

See also Which side of the hub flange?

Noise from the pedal / bottom bracket, once per pedal revolution

Cracks, creaks, and rattles that occur once or twice per pedal turn can occur for a variety of reasons, so there are many things to check:

Pedals loose?

Check this first, the pedals should be screwed tightly into the cranks. The left pedal has a left ("reverse") thread. The threads of the pedals should be lubricated with grease.

Are the crank bolts loose?

With typical three-piece cranks, it is very important that the locking screws (which secure the cranks to the bottom bracket shaft) are properly tightened. The opening where the crank is placed on the shaft can easily be knocked out. A slightly loosened crank cracks loudly. Over time it will move noticeably and may need to be replaced.

The threads of the bolts (or nuts) and the underside of the bolt head (or nut) pressing against the crank should be lubricated with grease.

Loose chainring bolts?

The chainring bolts are the 4 or 5 bolts that connect chainrings to the crank arm. They should be in good condition and firm. The threads and hex heads should be lubricated with grease or oil, but avoid lubricating outside the nuts. The nuts on typical chainring bolts only have two small notches that allow a tool to prevent them from spinning while the bolts are being tightened. If you leave the outside unlubricated, there is usually enough friction between the nut and the inner / middle chainring to prevent it from turning.

Loose bottom bracket / bearing shell?

Due to the thread of normal bottom brackets, the bearing shells tighten themselves up to a certain point. This sometimes leads to careless assembly, especially on the right (firmly connected) side. If the right cup is slightly loosened, it will not necessarily come loose on its own, but it will not tighten completely either. The symptom of this condition is an occasional cracking or rattling when the left crank goes "over the hill" when pedaling vigorously.

This is a surprisingly common and regularly overlooked cause of unwanted noise. In general, you should check the above points first because they are easier to fix. The strength of the bottom bracket shell, on the other hand, cannot be checked without dismantling the crank, but it can sometimes be determined in this way:

  • Turn the cranks so that the left crank is along the seat tube, enclose the crank and the seat tube with both hands and push the crank in the direction of the seat tube.
  • Then turn the cranks so that the right crank is along the seat tube and repeat the process. Watch for a crack / squeak.

Pedal Problems?

Check the pedals for loose or poor bearings.

Bent chainring?

If a chainring is bent, it can drag the derailleur, especially if you pedal hard.

See my article on how to straighten chainrings.

Is the derailleur touching the crank?

If the derailleur top limit screw is adjusted too loosely, or the derailleur is not securely attached to the seat tube, the cage can rub against the inside of the crank as it moves along it. This can also be a symptom of a bent crank, possibly as a result of a fall.

See my article on adjusting derailleur gears.

Saddle squeaks?

Sometimes noises that seem to come from the bottom bracket are actually from the saddle, possibly from where the saddle frame is connected to the seat post or the connection between the saddle frame and the top. This sound disappears when you get out of the saddle and pedal while standing.

Creaking from the handlebar / stem?

If you have a pedal-synchronized noise that only occurs when you pedal vigorously, see also below about the noises from the handlebars.

Noises from the chain, once per chain run (about every 3-4 pedal turns, depending on the gear ratio)

This is a sign that something is wrong with the chain. You may be able to fix this or you may need a new chain.

Fixed chain link?

If you notice a regular, repetitive jump or an irregularity every 3 or 4 revolutions of the pedal, you may have a stuck chain link. This is usually the chain link to which the chain was connected during assembly. When the rivet is pressed into the chain with a chain riveter, the rivet pulls the outer plate with it, so that the two outer plates are pressed against the inner plates.

The easiest way to fix it is to put the problem area in a "Z" shape, with the fixed connection in the diagonal part, and then bend the chain back and forth. This loosens the fixed tabs a little and makes the chain link movable.

Bent chain link?

If your chain has a link that has been bent by a chain clamp, this can cause similar symptoms. In general, the bent chain link (or the entire chain) must then be replaced.

The easiest way to find stuck / damaged chain links is to shift the bike into the small / small combination (a gear you should normally never ride). In this gear, the chain is loosest and flexes more than in any other gear as it moves around the rear sprocket and through the pulleys of the rear derailleur. Slowly reverse the cranks while watching the chain run through the rear derailleur and you can usually tell the crack by the bad chain link.

Mixed old and new chain?

When new chain links are inserted into a worn chain, there is a slight rattle when transitions from the shorter (new) to the longer (old) chain links run over a sprocket. This can happen even if only a new rivet or chain lock is used. If a longer chain is required, always use a completely new chain.

Noise from the brakes

Is there any noise or rattling when you only apply one of the brakes?

Irregularities in the rim take effect once per revolution of the wheel

If the rim has an irregular width, the brake will apply more (or less) if the irregular part of the rim runs between the brake pads during braking.

This is often caused by a "dent" or bump in the rim, a large point caused by a stone or pothole, or other road damage. Dents in the rims can sometimes be fixed by gently working the rim with a hammer or pliers.

Note that dents of this type usually only affect a very short section of the rim. If you find that the “wide” area of ​​the rim is longer, it may be an indication that the braking surface of an old rim has been worn and thin from many kilometers of braking. Do not drive such rims, they occasionally cause sudden and dangerous blowouts!

A slight imperfection is not uncommon for brand new rims as the area where the rim will join at the butt is often slightly irregular. This type of irregularity usually "breaks in" after a few hundred kilometers and does not necessarily constitute a defect (depending on the severity).

Brake rattles the first time you press it - loose brake caliper

If the brake calliper is loose on the frame or the brake arms are loose on the central mounting bolt, the first actuation of the brake causes the brake arms to be pulled forward, which causes a slight rattle. This also causes incorrect vertical alignment of the brake pads as the brake arms slide forward.

See my article on caliper brakes.

Front brake rattles the first time you press it - loose headset

When the headset is loose, it usually sits in the frame with the fork facing forward. When you apply the front brake, the braking forces pull the fork backwards with a distinct rattle. If you brake lightly, the headset will move back and forth, rattling as you do so. You may be able to feel this through the handlebars.

The tax rate should be adjusted to prevent this type of play. This is easiest to check on the stationary bike: lock the front brake and push the bike back and forth while you watch for the headset wobbling. Sometimes it helps to put a finger lightly against the upper and lower cups to feel if they are moving against each other.

See my article on tax rate maintenance.

Cracking and squeaking from the handlebars

Noise from the handlebars usually occurs when pedaling hard, because then you usually pull hard alternately on both sides of the handlebars to balance the force of the pressure on the pedals. These types of noises should not be ignored as in some cases they are related to growing cracks in the handlebars or stem. Such cracks can lead to ruptures and loss of control. Avoid stems with clamp bolts behind the handlebars - see John Allen website for examples.

The first thing to check is that the clamp screw is tight enough. The threads and the bottom of the head should be lubricated with grease or oil; if not, the friction in the thread can prevent sufficient clamping force from being built up.

Some handlebars have reinforcement sleeves in the middle section that also serve as built-in spacers to match the diameter of the stem clamp. The main part of the handlebar can sometimes move within this sleeve. I've had some success with Loctite ® in these cases: put a few drops of it where the handlebar enters the sleeve, then use compressed air to push it into the gap. Let it set overnight before driving.

It's also a good idea to occasionally remove the stem from the steerer tube and liberally grease the inside of the steerer tube. Avoid overtightening the stem clamp as this can deform the steerer tube. If you have a threadless stem [Note des Übers .: also known as "AHeadSet ®"] this is usually not necessary.

Irregular crackling and creaking

Crackling shift cables when turning the handlebars?

Dry pulleys? (squeak even after chain lubrication and may feel warm to the touch. Dismantle and lubricate.)

Something in your pocket?

Once I spent a long time looking for it to find the source of the mysterious squeak of a companion on board, only to find that it wasn't his bike at all, it was the knee brace he was wearing on one leg!

Rick Mason still has:

I have another (strange) “always once with every pedal turn” sound for you - shoelaces! One day I was riding with laces that had good tight ends. The ends of the shoelaces hit the down tube each time (only on the left side) and made a slight, tinkling noise. It was driving me crazy trying to find the cause. I stayed on the chain side until I discovered it, more by accident. It was easy to fix - just tuck the laces into my shoes.

Lubricate bolts or nuts

There is a contradiction in thinking about using lubricant to keep bolts and nuts from loosening. But in fact it really works!

When you tighten a screw or nut you are working against two types of resistance:

  • Actual fastening due to the clamping effect due to the movement along the threads
  • Frictional resistance while the threads are pressed against one another and by the friction of the screw or nut on the parts to be fastened

Only the first force actually helps hold the pieces together. When the threads are dry, the frictional resistance is the limiting factor in how tight a screw or nut can be tightened to a given torque.

If you lubricate the threads and the surface of the nut or screw head, it will tighten more firmly with the same torque.

Lubricating the thread also reduces the risk of tearing the thread.