Knocking noise, help!
 

I have a knocking sound that occurs about once every rotation of the pedals. I have to be riding the bike and pedaling for it to happen. The sound can't be reproduced with the bike on a work stand. I've replaced the Bottom bracket spindle and bearings, cranks, pedals, chain, rear derailleur and rear wheel. The only thing left is bearing cups, I'm going to changes those in the morning. I think it's coming from the bottom bracket area, but it's hard to tell for sure while riding. Any suggestions.

Thanks

If it occurs with pedal rotation regardless of gear, then it is likely bottom bracket cups.

This was my first thought also.

I ran into a similar problem, ultimately discovering it was a pedal, of all things - and only when there was the pressure of my foot that occurs during pedaling (as opposed to the slight pressure of your hand on the pedal turning on the stand.) But you swapped pedals.

I've had to replace many freewheels because of chain pop, which typically is heard as a knocking sound in the bb area - this occurs at regular intervals but seldom (if ever) is it precisely synchronized with crank rotation.

Your use of the word "about" leads me to believe yours is somewhat asynchronous also.

It is usually worse under load and never reproduceable on the stand.

The solution for FW chain pop is a new chain and HG FW.

Is it during the power part of a pedal stroke? As in... does the noise happen on one side as the pedal is being pushed? Had a 'knocking' type noise occur when my crank arms were loose recently on a ride. These were on an octalink bb though.

I had a similar experience that was a pedal, exactly as AZORCH says.

Did you actually change the pedals? or take off and put back?

Tell us what you find.

I went to remove the fixed bearing cup, and it was loose. Never thought to check that, 3 hours to diagnose, 3 seconds to fix.


Thanks guys.

It always amazes me that those things can be loose. Every time I want to remove one on purpose it's a @#$%^&* chore!!!! Glad you found it!

Man - Don't ya hate it - Here you have detailed the mechanics of your ride and Knock - Click - Tick...

Whats even worse is when you are the only one who can hear it...

Knocking - Clicking - Ticking... Never more... Ever Nevermore...

Maybe its your ankles.......:rolleyes: