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View Full Version : Crank: Tick, Tack & Snap


beelnite
06-12-2008, 08:46 AM
I just took my trusty steed in for repair and adjustment everythings working great except my pedal crank. It's not impaired but every couple of cycles it will make a snapping sound - a tick like something gets stuck and pops.

Any thoughts?

The repair folks mentioned something about "tightening my lower bracket" and I wonder if that is causing the oddity.

Yes, I am a bike hypocondriac!

djasonpenney
06-12-2008, 09:31 AM
Yes, it could be the bottom bracket is loose. More likely (unfortunately) is that the BB may be worn out.

These pesky little lower-end ticks and snaps can be a b---h to figure out, I'm afraid. A friend of mine kept trying to eliminate noises on his Santana tandem with couplers until he narrowed it down to a bad weld on the chainstay!

You will have to use the process of elimination. Some possibilities include the saddle, seatpost, and pedals. The chainstay welds are not a likely candidate. :D

Do you have access to a trainer? Mounting the bike stationary helps isolate the front wheel and you can listen without wind noise interfering.

lynnef
06-12-2008, 09:32 AM
When I had that issue, one of my pedals had given it up. Don't accept the noise. Take it back. Bikes shouldn't make noises like that.

beelnite
06-12-2008, 12:01 PM
Thanks lynn & dj - yeah I'll need to take it back in, which is a bummer - I've already lost two days of riding and I feel like a part of me is missing.

Sigh - It's definitely in the crank itself - the inner part. I've eliminated everything else. I put my ride up on the rack and then cranked her and listened through the seat post (this works - you can hear the bearings in your wheels as well).

The odd part is that the noise is obvious so I'm wondering why my bike shop didn't mention it... I feel like they made an old crank worse - I knew it was "grindy" and worn - but still serviceable and not noisy until I got her back. So now I have to approach the service department - and it's hard not to be accusatory... any advice for how to be diplomatic and fair?

Meanwhile - $$$ - ugh.

lynnef
06-12-2008, 03:17 PM
crankarms can break, too. I've seen pictures. Not pretty. Maybe you want to put the bike up on a stand and shine a bright light all over the crankarms, and see if you can spot anything.

K'Tesh
06-12-2008, 06:23 PM
My last set of crankarms had a pedal crossthreaded, and when the pedal was removed and replaced correctly, it wouldn't tighten. There was nothing to do for it except to replace it.

They didn't have a spare to replace it with, so I had to replace both cranks, and since they didn't have cranks like the ones I was using, I ended up with an external bearing.... Better than New!

Rubberside Down!
K'Tesh

toddistic
06-13-2008, 12:31 PM
if it's creaking every few turns it sounds like what my old roomate had. his bottom bracket cup was loose. once we tightened it down the sound went away.



todd

beelnite
06-13-2008, 12:51 PM
Hey todd - thanks for the tip... in fact that's exactly what the repair shop told me prior to this whole thing. I sent my steed to the shop for a derailur cable and - they called up and asked if they could tighten the "bottom bracket" and I gave them go ahead...

Hmmm... ok maybe they just need to tighten it some more. Taking her in Saturday.

briandlacy
06-15-2008, 07:01 AM
hi Brian @ BIKEmpowered (http://www.bikempowered.com)here,

I'd not worry about breaking a crank - very rare - unless you weigh a great deal and push a ton on them all the time.

Likely you have a split bearing or broken bearing cage (a feathery clip of metal that holds the bearings in a ring for quicker factory assembly) that gets pinched every now and again in your bottom bracket (which is the axle that passes thru your bike, the 2 rings of bearings and 2 cups on either side that holds it all together.

It also sounds like you recently brought this to shop -- if it's been in the last month or so -- you may be able to talk them down on the price to overhaul it. Consider a sealed BB (shop talk for bottom bracket) if you do need it replaced.

If $ is tight - there's no danger in riding it as is.

I usually charge $25 plus parts if you'd like my help.

And if this has been helpful -- I'd be grateful if you wanted to pass the word around about my repair and riding skills classes.

Spinning our wheels for good,

Brian

chubbybiker
06-17-2008, 06:29 PM
I've been noticing some clicking and clacking down below but I wasn't going to call my LBS because I didnt want to be the new customer that "imagines" problems. After reading this thread I decided to rely on Roger @ Sunset Cycles. I explained the symptoms and he encouraged me to bring the machine by so he could check it out . Once again the experience and advice that flows freely on this forum has pointed me in the right direction. Thanks everyone.

beelnite
06-18-2008, 06:47 AM
For $54.00 ($25 Labor) my LBS replaced my crank and I'm rolling like new! I decided to go ahead because I was riding on the original crank that was about 20+ years old!

I could swear I picked up about 1mph!

Dang - in the last year - 1500+ miles, two new hubs - front and rear, new brake pads, new cables, new tires, one new rim - I'll have a "new" bike in no time!

But it's still cheaper than an all-zone Trimet or vehicle maintenance/gas/insurance by far and this cost is likely to be up front since I'm replacing 20+ year old parts.

lynnef
06-18-2008, 08:47 AM
But it's still cheaper than an all-zone Trimet or vehicle maintenance/gas/insurance by far and this cost is likely to be up front since I'm replacing 20+ year old parts.

More fun, too.