Author Topic: Bike repair - clicking bottom bracket  (Read 6996 times)

GuitarStv

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Bike repair - clicking bottom bracket
« on: April 07, 2014, 07:00:39 AM »
I think that two winters in heavy snow/salt/slush may have killed my bottom bracket in my Giant Escape, but wanted to run this by everyone first before I buy a BB removal tool and try replacing it (it's some kind of sealed cartridge bearing).


I get a clicking kinda sound and feel a bit of a clunk every time I put any real pressure/weight on the right pedal.  It seems to be more prominent when I'm carrying lots of stuff/when I'm going uphill.  There's no audible sound if it's pedaled very lightly (or the pedals are turned while the bike is upside down).  The sound doesn't happen when coasting, only pedaling.

I have tried the following in debugging this issue with no success:
- Swapped out the pedals and biked around
- Adjusted both front and rear derailleur so that the bike is shifting perfectly
- Greased the seat post and re-inserted it.
- Tightened up the bike saddle
- Checked the chain for bent/non-working links
- Tightened up the QR skewers.

There's no play at all in the crank arms, they're not wobbling or anything.  I was going to tighten the bolts on it, but there only seem to be rivets on the largest chainring (SR Suntour 28/38/48).  Pulling up/pushing down on the handlebars doesn't seem to cause the issue, as it's still audible when riding without hands on the bars.

Anything else I should try, or anything obvious that I'm missing?


Also, it might be a couple weeks before I can get this fixed . . . is it OK to ride on a bike with a dying/clicking bottom bracket?
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m8547

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Re: Bike repair - clicking bottom bracket
« Reply #1 on: April 07, 2014, 07:41:50 AM »
It sounds like you've been pretty thorough checking what it could be. I've had clicking caused be a loose quick release, and that was difficult to figure out. A few things you might have missed...

Check the saddle rails, both where they clamp to the seatpost and where they go into the seat itself. Or try pedaling standing up.

Make sure the headset is not loose. Even without your hands on the bars there is still some lateral force there when you pedal.

Inspect the frame for cracks, paying attention to welds since they are high stress areas and likely to crack if not done correctly.

Put the bike on a stand, or turn it upside down, and pull the chain off the crankset. See how it feels when you turn the crankset by itself. If it feel rough it could be bad bearings. See if you can put force on it in a way that will make it creak. You might not be able to since it's hard to put a lot of force on it without the resistance of the chain.

The bottom bracket could just be loose. If it's a thread-in style, it's easy to tighten with the correct tool. I recommend using a torque wrench because the torque spec is high and you are likely to stop before you reach it if you are tightening by hand. See here for common torque specs:
http://www.parktool.com/blog/repair-help/torque-specifications-and-concepts

While you're at it, make sure the crank arm bolts are tight enough. Those need fairly high torque, too. The pedals don't need much torque, but you should use grease or anti-seize on the threads when installing.

It could also be a problem with the freehub or cassette. If one of those is loose it could make noise, or the bearings in the freehub could be worn out. Taking off the cassette, cleaning and greasing the splines, and putting it back on is easy. Taking off the freehub is more difficult if the hub is shimano style cup and cone since it involves disassembling the whole hub. On my fancy cartridge bearing wheel all I have to do is pull hard and the freehub pops off!

Russ

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the fixer

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Re: Bike repair - clicking bottom bracket
« Reply #3 on: April 07, 2014, 10:16:29 AM »
Sounds to me like you need to tighten the bolts holding the crankarms to the bottom bracket. If those are loose the arms can shift and cause a creaking noise, especially if you do something like stand on the pedals in the 3 and 9 position. My bike does this occasionally.

somepissedoffman

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Re: Bike repair - clicking bottom bracket
« Reply #4 on: April 07, 2014, 11:26:05 AM »
another thing to look at: I've experienced clicking similar to what you described when the rear derailleur isn't perfectly adjusted.  The chain catches the little ramps on the cogs and keeps almost-but-not-quite shifting.  Would still appear to shift ok other than the clicking.

GuitarStv

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Re: Bike repair - clicking bottom bracket
« Reply #5 on: April 07, 2014, 11:34:22 AM »
Thanks for the comments everyone.

I think the rear wheel is fine, I overhauled the hub and replaced the bearing/greased it up pretty well about four months ago.  The tick isn't noticeable just spinning the cranks around lightly, only under pressure.  It happens when I'm out of the saddle as well as when I'm sitting down, so I think the seats out of the equation.  The rear and front derailleur are both shifting perfectly after I did some playing around this weekend.  Chain is a little worn, but not more than 1/8th of an inch.

There is no perceptible play with them at all from side to side when I was yanking around on them looking for looseness, but I'll try tightening the crank arms tonight.  I'll also give the frame a closer look for cracks and the like, but didn't see any this weekend when I was going over everything.
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little_owl

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Re: Bike repair - clicking bottom bracket
« Reply #6 on: April 07, 2014, 03:25:51 PM »
This exact same thing happened to me recently on my 20yr old Trek 7000SHX (which is in immaculate condition, by the way).  In my case, it was somewhat creaky around the BB and if I pedaled with a lot of force into my right foot then I got the clicking noise and feeling that you explain.  In my case it ended up being that the plastic cup on one side of the bottom bracket had cracked.  My BB was steel and the cup that threads in on the other side was a cheap composite.  So when pedaling hard the cracked plastic cup flexed and allowed the crank to flex ever so slightly and make the creaking noise.  I couldn't cause the noise by hand unless I REALLY pushed on the pedal hard.  I ended up just buying a new BB off amazon and now it runs like new - it also has an aluminum cup so that it should last longer.

It's pretty easy to get the BB out and check this.  Just remember that one side is usually reverse-threaded!  Also be careful not to cross-thread anything when putting it back in or you'll have to chase the threads...or worse.
« Last Edit: April 07, 2014, 03:30:43 PM by little_owl »

wizlem

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Re: Bike repair - clicking bottom bracket
« Reply #7 on: April 07, 2014, 07:29:09 PM »
My experience is clicking bearings is caused by the bearing being too tight. Since a sealed cartridge bottom bracket isn't adjustable it's not very likely to suffer from such a problem. If you can't noticeably feel anything is loose by moving it by hand, I doubt you'll get any trouble from the BB when riding. Can just wait till it gets "grindy" or loose to replace it. Good to check everything else suggested though.
« Last Edit: April 07, 2014, 07:32:06 PM by wizlem »

GuitarStv

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Re: Bike repair - clicking bottom bracket
« Reply #8 on: April 08, 2014, 06:28:35 AM »
Hmm . . . well, last night I tightened the allen key bolts as hard as I could on the right crank. . . didn't budge at all, so I did the same on the left crank and the bolt actually moved a little bit.  It's weird because there was no play at all in the crank arm, and the noise was coming from the right hand side.  I didn't hear any clicking on my ride in to work today, but it was pouring rain and noisier than usual . . . so maybe that was masking it.  :P  Hopefully I can hear if this has fixed the problem on my ride home tonight.
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el Katz

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Re: Bike repair - clicking bottom bracket
« Reply #9 on: April 08, 2014, 08:57:45 PM »
In my experience the clicking is caused by worn splines on the crank.  If you normally don't, use Loctite blue on the small bolts that hold the chain rings on as well as the crank arms. The splines will wear when the cranks get slightly loose. The chainring tip is free to you but cost me about $100 to learn.

scottydog

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Re: Bike repair - clicking bottom bracket
« Reply #10 on: April 14, 2014, 07:28:27 AM »
http://www.jimlangley.net/wrench/keepitquiet.html

Thank you for sharing this!  I had a ringing sound coming from my front wheel, and with the help of this URL I eventually discovered it was because the rubber seal was rubbing on the hub.  It was hard to imagine the tiny rubbing could cause such a lound ringing noise while riding, but I believe the rubbing was causing the hub's housing to resonate.  It's a dynohub, so the housing is pretty beefy, and it actually sounded a bit like when you wet your finger and rub it around the rim of a wine glass.  A tiny squirt of silicon spray stopped the rubbing and the ringing.

I've had the clicking noise caused by a loose crank arm bolt as well.  The first time was about a month after getting my new bike, and it happened again after this year's spring thaw.  Resonance made this sound worse than it was, since it's a box bike and the wooden box amplified each click.