goldfinch

I have a small Giant Rincon budget mountain bike that my sister rides when visiting. I bought it used for cheap ($10). The bottom bracket was shot. The shifters shot. Most everything in bad shape but it did brake (mechanical disc brakes) and the wheels seem fine and true. For is just a spring fork, ugly but works. So, I took used parts to rebuilt the drivetrain. When I rode it, it had a puzzling creak that would come and go when pedaling. It felt like the bottom bracket and there was evidence that the bb was at one time partially cross threaded. I did try a different bottom bracket and different crankset and it made no difference. I brought it in to our local bike coop and they retapped the bb shell and checked the frame to see if it was bent. Frame straight. Replaced the threaded bb and no change. Still creaks.

Other suggestions? It seems as if there was enough threads to hold the bb tight but it is odd to screw in, one person has to hold the axle level so it screws in straight.

If in fact it still is the bb any suggestions? Or toss the cheap frame and start all over?

TPL

Be sure that your shoes are not intermittently rubbing against the crankarm

Had a customer once with a similar problem ....they brought the bicycle in 5 times with a on and off squeak

Finally I went out on a side street with him riding ....SQUEAK ....guess what ?, his shoe was rubbing against the crankarm

Told him to ride with his feet further outboard on his pedals = END OF SQUEAK !

goldfinch

Funny, but I am sure that is not it, I've ridden with many different shoes and I've never done such a thing. I did swap out pedals in just in case but it made no difference.

Andrew R Stewart 

Check all the other stressed parts. Seat on post. Post in frame, Stem/bars. Spokes at the nipples and their crosses. For starters. Andy

pennpaul

I had/have a similar issue with my road bike. I disassembled, cleaned, and regreased my BB but that wasn't it. Bunch of people here suggested to lube my seatpost inside the seat tube. Yep!

I've had to regrease it once now at 500 miles.

goldfinch

Did all but spokes. Will do. Thanks.

rydabent

Examine the frame closely. I have know frame cracks to make unexplained creaks and noises.

goldfinch

Good idea. Thanks.