Clanking when out of saddle - Help

bobtbuilder

Hi folks,

My bike had developed a loud "clank" noise which only appears when I am climbing in the out of the saddle position. The noise only appears when putting force through the non-driveside pedal and only at the bottom of the pedal stroke.

I've checked that the pedal is tight but don't know what to look at next.

Any ideas?? Thanks.

In_the_big_ring

I've had a couple cases on unidentified clanking when putting power through the pedals; on one occasion it was a loose water-bottle cage and the creaking came as the frame flexed when really pushing down on the pedals. On another occasion, also whilst standing, it was a loose headset that made noise as I pulled up on the hand bars whilst mashing down on the pedals. I've also had noises when I've had a loose spoke, and as it flexes it rubs against its neighbours. Sometimes, carbon frames just creak as they flex. Try this to see if you can isolate the noise. Stand next to the bike and lock out front the front brakes. With your foot, push down quite hard on the pedal as if you were testing the flex of the frame. See if you can isolate the noise. That should rule out loose bottle cages or a creaky frame. If there is no noise then it may be coming from the BB/crank set. For the headset. Again, locking out the front brakes, push forward and back to see if there is any play in the headset. If there is then tighten it up. You can also feel all the spokes to make sure that they are tensioned the same.

Bozman

I got a similar noise a couple of days ago, there was no noise until i got out of the saddle... i'd caught my sensor while i was transporting the bike. It'd moved a few mm's so that it was just missing the magnet, a bit of wheel flex and knock, it took me long enough to bloody realise what it was.
Note - RS80s flex.

xixang

I've got exactly the same issue on 1 bike. I completely stripped the bike down to components and frame (not because of this though) and rebuilt it from scratch and it was still there. Thorough exam of frame forks etc never revealed anything so I've ended up living with it. Not wheels as they were changed to test for the creak or b/b as thats been replaced. Would be interested to see if you ever solve this

graeme_s-2

Are you sure it's the bike and not you?

Twostage

Could be loose chainring bolts although in my experience that was a creak rather than clank.

bobtbuilder

Thanks for the ideas peeps. I'm going to take a look at the things suggested on Saturday and see if I can get to the bottom of this.

Just to clarify - it is one very loud clank per revolution and only on the non drive-side at the bottom of the pedal stroke.

I've tried climbing out of the saddle whilst only resting my fingers on top of the handlebars and the noise still remains, so I'm fairly confident it's nothing to do with the bars.