nasty noise from crank - What is it?

thanks for comments on this - i think its one sound per cran
revolution, its more of a clicking sound(s) then a clunk. The crank ha
already been tightened so i think we can rule that out. I think th
bottom braket - (thanks i now know what this bit is called!) - may b
at faulty. I suppose it may be a question of opening the thing up an
having a look inside. Happens when both standing and sitting.

cheers

Dan.



Roos Eisma Wrote:
"Pete Biggs" writes:

danielstevens wrote:
It's making a brittle sound and feels very brittle, especailly whe
i
put alot of pressure on the peddles, going up hill for example.

When it does make a noise, is it one sound per crank revolution?
click
or clunk? Could be a loose crank if it's on one side only; cran
will
need replacing if it comes loose again after retightening. Could be
elsewhere on the bike but coinciding with pedalling, including fro
the
rear wheel hub.

Or could be a loose or faulty bottom bracket (part inside fram
between
cranks), especially if cranks have play when grabbed and pulle
sideways.

Or is it more random tinkly noise? : Bottom bracket problem, perhaps.
Or
again, it could actually be coming from somewhere else.

Does it happen when standing up on the pedals (not sitting o
saddle)?

And if you feel it mainly on one side: ball bearings inside the pedal.

Roo

--
danielstevens

danielstevens wrote:
thanks for comments on this - i think its one sound per crank
revolution, its more of a clicking sound(s) then a clunk. The crank
has already been tightened so i think we can rule that out.

Not necessarily. A crank that's damaged badly enough may soon click or
clunk again after it's refitted. The square hole (assuming the most
common type) of the aluminium crank can deform or become too large for the
steel bottom bracket spindle it wedges onto.

Some more simple things to check: Chainring bolts are tight, crank is not
tapping front derailleur, shoe laces aren't tapping crank (I'm not
joking), pedals are ok (try different pedals if you have/can borrow any).

I think
the bottom braket - (thanks i now know what this bit is called!) -
may be at faulty.

Could be.

I suppose it may be a question of opening the thing
up and having a look inside.

A lot of them are sealed units and can't be serviced.

Happens when both standing and sitting.

Not the saddle or seatpost then, and won't be a problem with hub or chain
if it's one click per crank rev. We're making progress :-)

~PB

[BB]
I suppose it may be a question of opening the thing
up and having a look inside.

A lot of them are sealed units and can't be serviced.

Just in case that worries you: they can easily and cheaply be replaced.

~PB