The first thing you need to realize that there may be multiple
noise sources, and if you bring in your bike to have a mechanic check it out, don't get
too annoyed when he/she starts finding various things that you're positively sure are not
the noises you were hearing. You've got to take things one step at a time and rule out
everything you can. Also, if you're used to a bike from yesteryear that ran
silently, the gospel truth is that you'll never get a modern bike to run
that quietly, at least not one with gears. The very things that have been
done to improve gear shifting (primarily to the cranks and rear cogs, where
a lot of machining has been done and sometimes even pins riveted in) result
in quite a bit more drivetrain noise these days. Even the move to more
gears, requiring ever-narrower spacing between sprockets and cogs, has been
a factor.
A few basics first-
- Noises frequently sound like they're coming from someplace other than their actual
source. This is because just about any material under tension tends to be an excellent
transmitter of noise and vibration, including chains, spokes
and even the frame itself.
- Many noises aren't even coming from the bike, but rather accessories that are
attached to the bike. A very common non-bike source of noise is the interface between a cleated
shoe (the type that click into the pedals) and the pedal. Whether it's LOOK, Time,
Speedplay or SPD,
this can be a definite source of noise, which is why our mechanics will frequently ask
that you bring in your shoes along with your bike.
Another source of noise are the very shoes themselves! Recently we've had
two cases of noise that seemed to be coming from the drivetrain but was, in
fact, coming from loose cleat hardware embedded in the shoe. The
solution was simple...we glued down (using silicon sealant or bathtub caulk)
the loose fittings.
- When describing noises, you need to categorize them as either high-frequency
"clicks" or low-frequency "clunks." This is very important, since they
indicate very different potential noise sources! Also note whether you actually feel
something happening or just hear it.
- Keep in mind that noises are not always an indication of impending trouble. The
rear cassette (or freewheel on older bikes) will vary in loudness through its life...in
general, being somewhat noisier when new and quieter as they age (and the internal parts
become a bit less violent in their springiness).
- There will be some gear combinations where a certain amount of
grinding or scraping noise is unavoidable. Typically, on a 2-chainring
(double) bike, this will be in the small front/small rear gear
combination, as well as large front/large rear. On a 3-chainring bike,
it will come from the middle front/small rear, small front and 2
smallest rear cogs, as well as large/large.
Now we're ready to take things on one at a time!
Handlebar, especially where the brake levers
attach to it! This is extremely common, on new bikes as well as old. Keep in mind that the
handlebar is constantly flexing and, especially on road bikes, the part that the lever
mounts on is a veritable noise-magnet. The easiest way to tell if this is a noise source
is to try flexing the bars around and listening for noise, and then loosen the screws that
hold the brake levers to the bar and try again. If the noise is still there with the
levers loose, then that's not likely the source. When re-tightening, make sure the threads
on the bolts are lubed!
Stem. Make sure the binder bolts that tighten the
handlebar to the stem are well-lubed and tight. Also, pull off the stem and
lightly grease the
surfaces that contact the fork (or, on an older bike with a "quill" stem,
the wedge that contacts the inside of the fork), and especially be certain the
you grease the underside of the allen bolts, since that interface itself can
be a source of noise. It can sometimes help to put a thin layer of
grease on the part of the stem that grips the handlebar.
STI Road Bike brake levers.
Check out our separate article on this topic. Applies only to 1998-and-later Ultegra and 1999-and-later '105
equipment.
Cranks. Check to make sure that not only are your
chainring bolts (the five bolts that hold the chainring to the crank) tight, but that they
are lubed as well. This means backing them out, one at a time, and applying either a very
heavy oil (Phil Tenacious, for example) or a lightweight grease (just about anything
marketed for bikes) to both the threaded surfaces of the nut & bolt as well as the
areas where they contact the chainrings. Also, especially if you're using aluminum
chainring bolts (which we no longer recommend for most people), check them carefully to
make sure they haven't developed cracks. They will fail eventually (aluminum just isn't
strong enough for long life in this application) and, prior to completely breaking, they
will make pretty severe ticking noises.
On newer "pipe-style" cranks (as found on any 10-speed equipment as well
as most higher-end mountain bikes) the axle needs to be lubed where the left
arm slides onto it, as well as all bolts. Tru-Vativ, SRAM, Bontrager & FSA
cranks should be tightened to spec with a torque wrench, while the newer
Shimano cranks are a bit less critical in this regard.
For older square-taper cranks, remove the crank arms and check to make
sure there's no distortion of the square-cut surfaces. You're looking for
any rounding of the edges where the crank arm mates with the spindle. Also,
make sure somebody didn't apply a
bunch of grease to the flats...this is not recommended, since the crank's
machined surfaces will "ride" on the grease instead of making strong contact
with the bottom bracket spindle, and this will rapidly accelerate wear of
the mating surfaces (please note that, on this point, there is great
disagreement on the 'net, while most experienced bike shop mechanics insist
that the surfaces not be greased).
Pedals. A great number of creaking
bikes can be traced to pedals that either aren't quite as tight as they
should be, or haven't been removed & regreased in a very long time. Pedals
need to generally be installed a bit tighter than most believe. The dangers
of a too-loose pedal are not just added noise, but movement of the threads
which can damage the crank. In addition, the sprung part of a clipless pedal
(the movable part that snaps around the shoe's cleat) can be noisy if it's
dry or worn out. Try some lube first, but old pedals may simply need to be
replaced.
Bottom brackets. With the advent of
cartridge-bearing bottom brackets, noise problems are more common here than before.
Two things are going on...first, you have a design where your bearings are sitting in a
cartridge, and that cartridge sits on top of the axle. Problem is, the axle flexes,
changing the amount of contact between it and the bearing, which causes clicking noises.
The other problem that shows up with cartridge bottom brackets comes from the interface
between the cartridge shell and its bearing. This problem can sometimes be alleviated by
removing the bearing from the shell and using anti-seize compounds on the contact points.
Wheels. We've had many customers who
were
absolutely, positively certain that the creaking noises were from the
bottom bracket. Turns out quite often to be the front quick release! Took awhile to isolate it, but sure enough, that was
the source of the noise...it just had to be reinstalled a bit tighter and the noise went
away. We had another customer who'd been complaining about noises on her bike for
some time, and we just couldn't run them down, even after pretty much tearing her bike
apart and reassembling it. And then, on one of my Tuesday/Thursday rides up King's
Mountain Road, I just happened to catch up to her riding up the hill and, thankfully, the
noise was there, quite audibly so, and it was quickly apparent it was from the spokes in
the rear wheel. They were "unloading" as they approached the ground as
they rotated, and then regained tension as they moved away. We added just a bit more
tension and all seems to be fine now (and Laura, if you're reading this and hearing noises
again, please let me know!).
Spoke reflectors can be another cause of wheel noise, especially if it comes and goes
as you go through corners. Make sure the reflector is solidly wedged into the spokes
(which usually requires sliding it up towards the rim as far as it will go).
Saddles. A BIG source of noise trouble, and
frequently saddle noises will mimic crank noises since both tend to occur at the exact
same frequency (same part of the pedal stroke). Sometimes the noises occur from the
saddle rail/seatpost interface, in which case you should disassemble the seatpost, grease
all threaded surfaces and the underside of the head of each bolt, and reassemble. Also
put a bit of grease on the saddle rails themselves, where the seatpost
clamps onto them.
Rarely, the noise comes from the part of the rail that goes into the saddle itself.
We haven't found a permanent cure for this, but dropping some oil into the affected areas
helps for awhile.
Freewheels & cassettes (the rear cogs). Unless you've got a single-speed
trackbike, your bike has gears and a freewheel in the back that allow your wheel to move
while your pedals remain stationary. We call this "freewheeling"...in the
old days it was simply coasting.
The method used to allow this involve ratchets in the rear wheel mechanism...a very
simple device that allows for free movement in only one direction, allowing you to either
coast or pedal without needing to engage any levers etc. These ratchets are very
much like what you'd find in any tool set, and when you spin them, they make noise,
usually at the rate of about 18 or so clicks per revolution of the wheel. In some
designs, the ratchets are quite noisy, either because they're located closer to the
outside of the hub mechanism, or because they're extra-strong. In other hubs, these
ratchets are very quiet, perhaps because they're located further inboard or packed in
heavier grease.
Often, a freewheel that started its life fairly quietly will become noisier over time,
and this is rarely cause for concern. In general, a noisy ratchet is a happy
ratchet, provided that you don't notice it binding if you try to turn it by hand.
Please note also that the tone of the noise can change depending upon what gear you're in,
even when you're not pedaling. This is because the chain is exerting a pull
from one side of the rear cogs or the other, depending upon what gear it's sitting on, and
this affects how the bearings and ratchets are carrying their load. This is
perfectly normal.
Indeed, the scariest of freewheels is one that has suddenly decided to go quiet.
This may be an indication of ratchet failure or near-failure (there are two different
ratchets in each freewheel, so one can fail and the freewheel will still function for a
time), and it would be wise to bring the bike in to the shop to get checked out.
Frames.
Some frame designs use elastomers (rubberized bumpers and vibration
dampeners), and since these are essentially moving parts, they require
lubrication and are susceptible to drying out, especially if ridden in the
rain. Also, anything that clamps or mounts onto a frame can be a suspect,
including the the bearing race that sits on the front fork.
Last updated
03/25/09 |
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