rattley/clunky drive train?

rowlers

in certain gears I can feel a rattle through the pedals. this happens at when the pedals are under a fast and constant load. If I stand up for example and "pump" the pedals I can't really feel it, but seated I can feel it. Only seems to do it in certain gears, but it is isn't the chain catching. There doesn't appear to be any play in the BB.

I'll prob take it to LBS for a service soon any way before it comes out if its 12 month guarantee, but I'd like to know what it could be before it goes!

Cheers

supersonic

Need adjusting? Try cleaning the cable, and readjusting the gears. Check for tight chain links, and that the hanger is straight. Could be worn parts - my guess is rubbing on the front mech.

rowlers

can't possibly due to worn parts, I've only done about 300miles on it :?

it feels more like it is coming from the crank, but it feels solid when I have a look.

I too thought it was the front mech catching, but I have checked this and it doesn't catch!

I'll have another look

thefartingcockeral

Could it be that you have grit or something in your bottom bracket. I had only done 300miles on my crank. I stripped my down today as I was having the same problem. Thought the chain was rubbing on my front mech but no. Cleaqned the drivetrain and relubed it but made no difference. So i spent today removing the bb cleaning the shell and cleaning around the spindle and touch wood the noise has gone. What sort of bb and crank do you have?

rowlers

No idea what the BB/crank is!!

Looking at the specs on TREKs website, the crank is a Shimano M442 44/32/22. It doesn't say what the BB is though.

thefartingcockeral

Hi, smae crank as myself. The bottom bracket (BB) is the part that connects the crank arms.
Might need to remove and regrease or take it to lbs.

supersonic

The BB will be a seasled octalink unit. They are quite hardy units, but could be the cu;prit.

Parts can wear after 300 miles in some cases!

mastermosher

Supersonic, i have a 442 shimano and it is definitely square tapered. Stripped it this weekend.

supersonic

Interesting, seems to be two versions!

http://www.bike-x-perts.com/en/product_ ... _id/123568

Probably some other funny letters somewhere that the web sites never tell us.

Square tapers BBs actually tend to last a little longer, but more prone to flex and loosening issues.

Park Tools has a good page on diagnosing noises.

mastermosher

sorry supersonic. Did not mean to be a git.
If you go to the shimano website there are 4 versions of the 442 of which 2 are octalink and the other 2 are square taper. I have a top end Cannondale of which i ditched the external bearing set up that it came with after 400 milesfor the cheaper more longer living set up and not to mention cheaper.

http://cycle.shimano-eu.com/catalog/cyc ... 8309670803

supersonic

Lol, you weren't, didn't even cross my mind! Problem is Shimano's numbering can be vague to say the least!

I run an LX Octalink and BB, find it stiff, cheap, and good performing. The external stuff still not convincing me, hear so many problems!

mastermosher

I had an FSAafter burner megaxo which was pants and lasted 200 miles and that was not even driving it hard or through acid. I also had an XTR set up which laster 400 miles and after that decided to go back to sealed inner bearing set ups.

supersonic

I still have an UN52 somwehere, 10 years old, 1000s of miles on it!

mastermosher

My wifes XT set up on here Rockhopper has lasted 2700 miles. Thats cost effective.

rowlers

didn't realise they could wear out so quick! Deffo need slooking at anyway.

cheers folks!

supersonic

Depends on conditions as well with other parts ie sandy soil near the sea can eat chains and cogs in weeks.

rowlers

well I do live less than a mile from the coast!
Chain would have a coating of rust over night if I didn't keep it well lubed!