Rear wheel groans when I pedal out of the saddle

[enentrup]

It sounds like a brake pad rubbing as the frame or wheel flexes, but that's not it. When I'm climbing or accelerating quickly, and get out of the saddle to pedal hard, I get a groan from the wheel. I know it only happens on ONE downstroke, but I don't remember if it's left or right or if it varies.

Not sure what it is. Could it be:
--loose spoke(s)
--something screwy in the hub
--???

Thoughts?

Thanks!

[j beede]

Have you confirmed that the noise is coming from the wheel by swapping wheels to see if the noise follows the wheel? In my experience it is fairly common for crank sets to creak or groan under stress. Can you reproduce the noise on a trainer or by putting your front wheel against a wall, full braking, and then standing on the pedals? This could be a two or three person job I suppose--one to hold the bike, another to stress the bike and the third to "look" for the noise.

[enentrup]

Great advice...I'll try that soon and come back to update the thread.

(01-20-2010, 09:19 PM)j beede Wrote:  Have you confirmed that the noise is coming from the wheel by swapping wheels to see if the noise follows the wheel? In my experience it is fairly common for crank sets to creak or groan under stress. Can you reproduce the noise on a trainer or by putting your front wheel against a wall, full braking, and then standing on the pedals? This could be a two or three person job I suppose--one to hold the bike, another to stress the bike and the third to "look" for the noise.

[Bill]

A little trick I have used before is whoever is checking for the source of the noise can roll up a piece of paper and put it up to their ear for precise hearing. As goofy as it sounds it does work.

[Jordan300]

It could be the hub bearings. What kind of wheel is it?

[DaveM]

Check that your crank arms and pedals are tight. A lot of creaks and groans can come from this area.

[jr14]

Also check the chainring bolts. I've seen the chainring or its parts including the bottom bracket cause everything from a small squeak to a creak to a thump on pedal strokes.

Of course, it could be your headset.

*edit* It could be a LOT of things. Check everything everyone has suggested.

[j beede]

If there is a Harbor Freight store near you they sell a mechanics stethoscope for a couple dollars that may be of value. It has a metal probe that helps isolate the source of noises. WARNING: you will end up rebuilding/repacking/replacing all of your bearings after you use this tool!
...j

[jr14]

Aw...That's half the fun of wrenching on your own bike!