Bicycle Mechanics - Bottom Bracket? Creaking?

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NM-NewRoadie
05-07-06, 09:40 PM
HELP! I'm trying to figure out where this sound is coming from. It sounds like a "creak" coming from the bottom bracket. BUT the bottom bracket is brand new. I just replaced it about 700 miles ago with a brand new Nashbar (rebranded RPM) bottom bracket. I even took the cranks off last week and tourqed down the bottom bracket again.
The CRAZY part is, that it doesn't do it all the time. It rarely does it on my 20 mile commutes, and usually pops up towards the END of my weekend group ride (at around mile 40 or so)
I'm going to do some "testing" tomorrow to see if it might be gear related but just wanted to see what other idea's people have to fix this thing.
Thanks in advance, Ben
HELP! I'm trying to figure out where this sound is coming from. It sounds like a "creak" coming from the bottom bracket.
Very common is actually a creak from a crank that is not properly tightened up. That type of creak usually develops a while after the crank has been tightened. In investigating, you can try to operate one pedal only and see whether the creak may go away letting you know which side might have got loose first. People usually underestimate the torque needed for tightening a crank.
NM-NewRoadie
05-08-06, 08:07 AM
Thanks for the idea, but I retorqued (with a torque wrench) the crank bolts, to 36 foot pounds when I had the cranks off a week ago checking the bottom bracket. The install instructions said 35, but I figured an extra pound couldn't hurt.
Any other ideas?
Is it a Campy sealing bearing BB ?
NM-NewRoadie
05-08-06, 10:49 AM
Is it a Campy sealing bearing BB ?
no it's an isus (RPM rebranded as nashbar) sealed bearing bb for use with a compact crank shimano setup.
anyone got the cure-all answer for this? :-)
Did you grease the threads for the Nashbar BB and lockring real good? Is the BB itself fully threaded and tight? Is the lockring good and tight? Just a theory. I've got a persistent creak that's a little intermittent too, I'm using an older Shimano cartridge BB square spindle. I'm thinking its the culprit, I rebuilt my pedals, tighted the crankarm bolts very tight and even made sure the chainrings were secure. Let us know what you come up with.
zoridog
05-08-06, 12:00 PM
I had a creak in what I thought was the BB. When my right foot was pushing down I heard the noise. I was sure it was the BB because it only happened when I was pedaling.
It was a loose stem! Not loose enough to affect steering but enough to make the noise! I guess I'm pushing/pulling on the handlebars as I pedal.
Cabrales
05-08-06, 01:02 PM
It's gotta be the shoes;) Seriously though, sometimes my shoes will make a squeaking noise if they are not tightened enough. Could it be that after a long/hard ride the shoes are getting loose and making the noise? How about the saddle? Could the sound be coming from the saddle?
Does it feel different when it creaks? If it does, you might want to reface the bottom bracket shell. I've had to do that regularly when I've installed an ISIS BB. They seem to be touchy for some reason. If it doesn't feel different when it creaks then the refacing probably won't help.
NM-NewRoadie
05-08-06, 04:32 PM
Does it feel different when it creaks? If it does, you might want to reface the bottom bracket shell. I've had to do that regularly when I've installed an ISIS BB. They seem to be touchy for some reason. If it doesn't feel different when it creaks then the refacing probably won't help.
what is this refacing you speak of? yes it does feel different when it creaks, kinda like a clicking....
Retro Grouch
05-08-06, 04:37 PM
I had a creak in what I thought was the BB. When my right foot was pushing down I heard the noise. I was sure it was the BB because it only happened when I was pedaling.
It was a loose stem! Not loose enough to affect steering but enough to make the noise! I guess I'm pushing/pulling on the handlebars as I pedal.
Yup. Everything on a bicycle sounds like it's coming from the bottom bracket. Since you said it is more likely to happen at the end of a 40 mile ride, I'd check into things like the seat clamp.
what is this refacing you speak of? yes it does feel different when it creaks, kinda like a clicking....
It is something your LBS will need to do for you.
Yup. Everything on a bicycle sounds like it's coming from the bottom bracket. Since you said it is more likely to happen at the end of a 40 mile ride, I'd check into things like the seat clamp.
The worst noise I ever had from the bottom bracket was actually my right shoe. The SPD cleat insert was shuffling back and forth inside the sole as I pedaled.
crazy_mtnbikur
05-08-06, 05:01 PM
hello is there any old trick/remedies to getting a crank arm off with out a puller (dont have access To one.) any sugestions would be apreciated.thank you in advance.
I had similar problem with a creak which happened every pedal rev, wasted good 6 hours messing with the crank and bracket before I realized the sound actually occured while putting pressure on the left pedal which was actually caused by the shock/strut... just putting some lube fixed that problem.
I would just buy the multi crank puller extractor $15, but I would imagine a good whack with a hammer would loosen the crank :)
Maybe someone can give me a hint on how to keep by bottom bracket becoming loose, I really didn't want to overtighten the holding nut and mess up the bearing cup like I did last time...
NM-NewRoadie
05-11-06, 01:41 PM
well, through the ever popular SWAG method (Scientific Wild Ass Guess) I determined that it is not the saddle, shoes, or cleats. (it's a road bike so I doubt the suspension fork guess will help :-) I also took the BB apart again and regreased the threads and put it back together. no change, in fact it is now doing it on shorter rides too. So I decided it was time to turn it over to a pro. Dropped it off this morning and will pick it up tonight. I'll let ya'll know what he says/did and what the result is.
WoodyUpstate
05-12-06, 12:14 PM
I've silenced BB creaks by cleaning the threads thoroughly - BB & frame - and then wrapping the BB threads with plumber's teflon tape ($2 at the local hardware store).
NM-NewRoadie
05-15-06, 08:54 PM
After removing, and re-installing the bottom bracket it got worse. So I gave up. Took it to the bike shop and he reported I was using WAAY to little greese on the threads. He also gave me a great tuneup on my derailers (had done a compact crank install and never got it working exactly right) and trued up my back rim. All for $50, and had it back to me the same day. New favorite mechanic in Albuquerque is Rob Mion at Fat tire. Only shop I've found that would let me make an appointment and not have my bike sitting there for 3 days doing nothing.
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