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View Full Version : Bottom Bracket / Crank Noise!!! Help....


bikerinNE
09-09-2008, 09:20 PM
My Bottom Bracket has a certain click to it at 1 point, always at the same time at the same spot in revolution of a pedal stroke. But, here is the catch, i only notice it under load.

So, why is this, I don't want to take my bike in just yet, as i can't really live without it.

Is there a simple fix, does it need adjusting, is it loose, can i tighten it, or is this a sign that the bearings need repacking or replacing? The only two parts of my bike that i don't have intimate knowledge of is Bottom Bracket and Headset, which i'm told needs replacing to, ugghh.

If anyone could shed some light on my Bottom Bracket... Thank you very much.

wyeast
09-09-2008, 09:45 PM
Sorry, but it seems like the bearings to me. :(

Curtiss
09-10-2008, 12:39 AM
Clicks are often difficult to diagnose, but for the Jedi grand-master's answer, see Sheldon's article here (http://www.sheldonbrown.com/creaks.html).

rainperimeter
09-10-2008, 12:53 AM
take your cranks off and tighten the cups. maybe check your pedals too.

bonny790
09-10-2008, 06:47 AM
I your bike a bare bones roadie or a loaded commuter? I ask because if the bike has lots of stuff bolted on and attached, check all the add ons before digging into the heavy stuff. Not long ago I had a click I swore was from the bottom bracket. A very snappy click at the same spot of the left down stroke under load. I snugged the BB. No change. Took it into the shop (new bike, after initial break in, but still within 6 mo check up) and he pulled the BB, repacked, and reinstalled. No change. Removed, cleaned, regreased pedals. No change. One night I was getting ready to start pulling everything off the bike no necessary for forward movement when I heard the click. Turned out to be the chain I have locking the saddle to the frame! I have a heavy-ish chain and padlock with a strap wrapped around everything to keep snug. I turns out that the strap was holding everything in just the right spot so that when I loaded everything just right, a link on the chain would touch the saddle rail and click!

Anyway, I've heard of it being pedals, seatpost, water bottle cage mounts, etc. Spend an evening with a few wrenches in front of the TV and go through everything.

Good luck!

brewcaster
09-10-2008, 07:40 AM
Ya, for me it was a bad pedal 2 months old. Bike Gallery replaced it, and I am click free, (and better pedals). Good luck!

K'Tesh
09-10-2008, 10:09 AM
Sorry, but it seems like the bearings to me. :(

Henry, and Mark (my bikes) both have the same problem (loud intermittant creaking/popping sounds)... I've taken it to the wrenches at Perfomance and Bike Gallery, and:

We've replaced the:

Pedals
bottom Bracket
chain

We've lubed the:

seat tube
bolts holding the chain rings
bottom bracket
downtube/seat tube/chainstays

We've tightened the:

Cranks
bottom Bracket
pedals
bolt holding the seat

on both bikes. Nothing helps... the only thing that can be left is the frame or me, and as I can't be replaced, and it's happening on both frames, we're at a loss for its cause. What's worse, it only really happens as the bike is being taken on distance rides (so a short jaunt round the parking lot does nothing to allow the mechanics to hear it). :confused:

Theory has it that the bikes (both aluminum framed) flex under my weight (21stone) and power as I pedal and it's the threads where the bottom bracket meet the frame that is the source of the creaking.

Much of this was done under warranty, so I'm not out huge money, but it is annoying to all of us.

OnTheRoad
09-10-2008, 10:46 AM
A mechanic once told me about a hard-to-diagnose clink that the owner heard, but the mechanic could not hear when she road-tested the bike.

Then the owner and mechanic rode together to see if they could hear it then.

It turned out it was the zipper of the owner's jacket hitting the top bar.

tonyt
09-10-2008, 02:17 PM
When I was wrenching, I had a customer with a full-suspension MTB and he was complaining about a constant click.

I had it in the stand and would get nothing, but then get ON the bike and would hear it. Finally I realized that when the rear shock compressed, the position of the front derailleur changed relative to the cranks, and put the cable end right in that path.

Probably isn't what's going on with you, but thought I'd pass this on to all concerned.

My bet is on the pedals.

bikerinNE
09-10-2008, 04:02 PM
Thanks for the replies, will look into all that.

Tait
09-10-2008, 07:57 PM
Henry, and Mark (my bikes) both have the same problem (loud intermittant creaking/popping sounds)... I've taken it to the wrenches at Perfomance and Bike Gallery, and: ... <long list> ...

That's funny because my bike has had the same problem since the day I got it (and we have the same bike, if I recall). Mine is definitely related to the bottom bracket as the noise (somewhere between a snap and a clunk... definitely not a click) happens only when there's lots of torque on the pedals and as either the right or left side come to the 12 o'clock position.

I thought about having it looked at, but never did, and aside from the noise it's never been an issue. If you had a similar problem, I'm wondering if it isn't a quirk of the frames they used on these Rainiers. I may get it looked at soon, as my middle front chainring is bent beyond usability now, so I'll probably have to replace it.

K'Tesh
09-10-2008, 08:28 PM
That's funny because my bike has had the same problem since the day I got it (and we have the same bike, if I recall).

<snip>

I'm wondering if it isn't a quirk of the frames they used on these Rainiers.


Mark is a '04 Rainier, Henry is a '08 GT Transeo, I'm wondering if it's a property of large guy and aluminum frame... I'm big, I don't know about you...

Perhaps we should get to together and see if the sounds match.

Rubberside Down!
K'Tesh

btw: If you have an 04 Rainier I'd love pic of it at night as long as you haven't given it my retro-reflective treatment...

Jeff Wills
09-11-2008, 08:21 PM
take your cranks off and tighten the cups. maybe check your pedals too.

If that doesn't do it, take the cranks off, remove the bottom bracket , put some teflon tape on the threads of the cups and reassemble. Aluminum frame-bikes seem to be susceptible to noises coming from the BB threads. Remember to grease every metal-to-metal contact surface during reassembly.

My most newest bike (an aluminum Easy Racer Gold Rush recumbent, bought used) developed a screek-creak after the first week when I was pedaling hard . I was feeling bad because I thought I'd done all the right things to keep this from happening. Then the noise disappeared after a couple days.

I dunno... maybe it's possessed.


Jeff

bikerinNE
09-11-2008, 09:28 PM
my bike is a late 70's trek, steel frame. I don't have the tools to remove crank. I've done everything there is, as said above, aside from removing the crank. it's lessened considerably. but still remains....

If that doesn't do it, take the cranks off, remove the bottom bracket , put some teflon tape on the threads of the cups and reassemble. Aluminum frame-bikes seem to be susceptible to noises coming from the BB threads. Remember to grease every metal-to-metal contact surface during reassembly.

My most newest bike (an aluminum Easy Racer Gold Rush recumbent, bought used) developed a screek-creak after the first week when I was pedaling hard . I was feeling bad because I thought I'd done all the right things to keep this from happening. Then the noise disappeared after a couple days.

I dunno... maybe it's possessed.


Jeff

RedRiderPDX
09-12-2008, 07:05 AM
All of the above advice is good. I don't know if you're using an external cup-type BB like Hollowtech II or what... If nothing fixes it, you may either have a hairline frame crack or you might need to have your LBS chase and face the bottom bracket shell. Cheaper bikes might not have had this done well (or at all) and minor imperfections in the parallelism of the bottom bracket faces could be to blame, no matter how tight you crank the cups (which you shouldn't overtighten). Special equipment required. Go to a bigger shop to see about this....

vincentpaul
09-15-2008, 11:11 AM
+1 on the having the bracket properly tapped and faced at the LBS. It shouldn't cost much (with the right tools the whole job from crank dissasembly to completion of the facing and tapping should only take a skilled mechanic about 20 minutes according to Sutherland). Very few bikes these days have been properly tapped and faced at the factory. Its not just cheap bikes that have this problem. Very few bikes these days are sold with proper bottom bracket preparation. The very slight misallignment that results is often the cause of creaking/groaning/whatever-you-want-to-call-it.

keithwwalker
09-15-2008, 01:00 PM
Do not discount that the chainring is flexing under torque load, and that the chainring may have some alignment issue, or burrs, or other defect. Is your chainring fully machined and polished? Or is it just stamped and machined.

There is a reason njs keiran racer chains and rings are so expensive....

bikerinNE
10-02-2008, 04:34 PM
Do not discount that the chainring is flexing under torque load, and that the chainring may have some alignment issue, or burrs, or other defect. Is your chainring fully machined and polished? Or is it just stamped and machined.

There is a reason njs keiran racer chains and rings are so expensive....

I have no idea. I'm putting up with the noise, and going to move on to a LHT.

lazy72
10-15-2008, 09:45 AM
i had a problem like this years ago...bought/replaced stuff, plumbers tape on bb threads, etc.

a lot of clicks and creaks under load can be from loose or stripped chainring bolts. take 'em out, grease everything, center your chainring on the spider, tighten them down, go ride up a hill out of the saddle, then tighten again. steel chainring bolts stay tight longer than aluminum. worth a try.