Sound when pedalling

Question

I have got a new mountain bike(hardtail wtih powerspline bb) and it is on 100 kms. When I push the pedals I hear little sound from the left side. It is only from the left and I think it can be the crank or pedal?! (not sure if it can be the BB as long as I hear it from the left). The sounds comes when the crank is almost in maximum down position.

The interesting is that when I go out for a ride the sound/creak comes after 8-10 kms. After that I return home>clean the bike>go out for next ride>it comes again after some kilometres. It is very strange. Is it possible to be something different, like mud from the tires or something like that?

I have checked the cranks and I think they are tighten enough to the BB. I am not sure about the pedals, however. Will it help if I apply on them chain dry lube and tighten them?

Thank you in advance!

Answer 1

Maximum down position is odd - that's when the power stroke is over so its not the pressure causing your noise. Did you assemble it yourself? Could be a loose pedal, or a pedal bearing needing lube.

Try popping the chain off the chainwheel and pretend to pedal. See if the noise still exists. If yes then its not your chain.

Finally - since your bike is new, have you taken it back to the shop for a tune up? Almost all bike shops offer a tune after 6-12 weeks to fix up cable stretch issues etc. A minor creak like this should be covered by that, or by warrranty.

Answer 2

Im not intimately familiar with powerspline, but

Noises generally come from the interfaces between parts. Things to check:

pedals, assuming aluminum crank arms and steel pedal spindles, make sure that there is a bit of grease on the threads where the pedal goes into the crank arm.

pedals again, if they are build in parts, if there is anything to tighten, check them.

crank arms, make sure they are tight. with ordinary crank arms, do not grease the interface between arm and BB spindle, the arms will draw on too far, and may swage open. grease the bolt that holds them on, make sure they are tight. If there are torque specs, follow them. powerspline, check that the interface is clean, make sure whatever bolt secures them is as tight as it should be. careful, steel into aluminum can lead to the aluminum threads pulling out.

chain rings, make sure the ring(s) are seated to the arms properly, pull the bolts out, grease the threads, reassemble, make sure they are tight

bottom bracket, what is the frame made of? how are the crank bearings secured to the frame? steel, traditional bb bearing cups threaded into frame, make sure they are properly tight. usually the right cup tightens to the frame and the left is adjustable. your noise is from the left, when all the way down, or nearly so. the noise could be the adjustable cup moving. i'd check this soon, if the cup is moving, you can distort the BB shell. ( I did it to the right side of an old bike of mine, had to retap the BB shell to italian ( it was french ) threads to get the cup to hold. ) If it is steel/steel, and you end up removing the cups, grease the threads when putting it back. otherwise, not sure. steel to aluminum gives rise to all manner of noise, something that keeps the corrosion at bay is recommended.

aluminum frame, sealed bearing,my daughter's bike is like this, I have not managed to remove the creaking noise yet.

Answer 3

Creaks are always difficult to track down, where the sound seems to come from is often no guide to the source. What is often the cause is the rear wheel, especially if its qr. Take the wheel out, clean the dropouts and wheel axle, a smear of grease on the dropout and reassemble.

Answer 4

I am happy to tell you that I fixed the problem. Cranks/bb/pedals, everything is good and not worn out. I fixed it with some bike lube. I lubed the place where the pedal goes into the crank with pedal INSERTED in the crank. 60-70 kms later no sound. :)