Bicycle Mechanics - Holy. Whaaat is this NOISE coming from my bike?

Hi all!

Can someone help me troubleshoot this?

Whenever i pedal (apply more force, eg climbing hills), there seems to be an intermittent noise coming from the crank/bottom bracket area. Sounds like bird chirping noises, with a light grinding sound and a "clack" sound whenever the crank makes a full rotation. The 'clack" sound always happens at the same spot when i pedal.

Is this due to my bb? Is it busted already? Or is it due to crank? As when i cycle and look down, i can actually see my crank wobble a little. Have already tighten the crank bolt. However, when the bike is stationary, i realised that there is actually some play in the crank (lateral movement).

Thanks!

What crank do you have (pics would help).
If there is play in the crank, you have a problem BUT we need more info to assist.

Remove and lube crank arm and lube bottom bracket area.Check bottom bracket threads are tight. Install crank bolts with blue loctite on thread if the crank arms keep coming loose. Check rear cassette to see if it is loose.

http://www.parktool.com/repair/byregion.asp?catid=14&imageField2.x=26&imageField2.y=9

Doesn't sound good... fix it ASAP.

I bought a nice machine once and found it was ruined cause the ally lockring on the drive side of the Synchros BB had cracked and the doofus who owned kept riding it and mashed the threads in the frame : (

ok thanks for the replies, i think it might be seizing up soon. It's square taper, a non series shimano crank. I used it for my commuter bike. Will send it for servicing soon

ok thanks for the replies, i think it might be seizing up soon. It's square taper, a non series shimano crank. I used it for my commuter bike. Will send it for servicing soon

Noises from the bottom bracket/crank area are notoriously hard to eliminate. Here's the guru: http://www.sheldonbrown.com/creaks.html

One thing to remember that all metal-to-metal contact should be lubricated, including all threaded connections. I've had to dissassemble & reassemble cranksets 3 or 4 times before tracking down the actual cause. In my case, the pedal threads weren't greased well enough. I removed the pedals, greased the threads, and reinstalled. Creak-be-gone!

ok thanks for the replies, i think it might be seizing up soon. It's square taper, a non series shimano crank. I used it for my commuter bike. Will send it for servicing soon

If it's the loose ball variety it's probably the cage that has exploded. Seen this quite often too, either with crank seizing, partially or not at all.

Stupid question. Is it possible you're hearing chain noise?

Depending on the chain lube you're using, and it's condition, is might simply be a matter of lubing the chain, and certainly you should eliminate that possibility before taking things apart.

Also note the crank position when you hear the loud "clack", duplicate it and examine the teeth just about to engage the chain at that point. If it's at the shift gate, or there's a chipped tooth, that's might be making the noise as it engages the taught chain.

After eliminating the simple possibilities, you can explore more complicated ones. If you approach the problem from the opposite direction, you could end up unnecessarily doing complicated, expensive and pointless work.

Stupid question. Is it possible you're hearing chain noise?

Depending on the chain lube you're using, and it's condition, is might simply be a matter of lubing the chain, and certainly you should eliminate that possibility before taking things apart.

Also note the crank position when you hear the loud "clack", duplicate it and examine the teeth just about to engage the chain at that point. If it's at the shift gate, or there's a chipped tooth, that's might be making the noise as it engages the taught chain.

After eliminating the simple possibilities, you can explore more complicated ones. If you approach the problem from the opposite direction, you could end up unnecessarily doing complicated, expensive and pointless work.

So in other words, use your brain?

So in other words, use your brain?

I don't like to put it that way, but with everyone having him start by taking apart the BB, I thought I'd remind the OP to start by checking the simple things first.

thanks for the replies, Its definitely not chain noise as my chain is always kept in a lubed condition.

Have brought it down to the lbs near my house for a check up, apparently the cause of noise was indeed from the bb.

The bb is already slightly bent, and was told it was probably due to the stress or too much force. No safety issues though, only some irritation to the rider from the noises made when pedaling.

So i guess i'll continue with it at the moment, and put up with the occasional noise. Might be changing a new bike too anyway.

Does it happen when you pedal standing? If not, try greasing the seatpost. I had grinding / creaking / popping noises just like you descrobe that I was convinced were from the BB - luckily I was wrong.

So in other words, use your brain?

You know with that kind of thinking you are gonna put yourself out of work... :lol:

It would be prudent to get the bb checked to make sure that creak isn't a bearing retainer that has failed as these can destroy an otherwise serviceable bb in short order. And when you out it back together eliminate the cages and fit loose balls instead as the bike will run smoother and that worry will be eliminated.

Make sure the pedal threads are greased as well as the threads on the crank bolts, that the chain ring bolts are also greased and everything is properly torqued.

The wiggly bottom bracket points to an adjustment issue and if this has been going on for a long time the bb may need a complete replacement.