Author Topic: Bike Experts - Loose cranks/bottom bracket?  (Read 13714 times)

GuitarStv

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Bike Experts - Loose cranks/bottom bracket?
« on: January 11, 2013, 10:09:23 AM »
On the ride home last night, my (not so) trusty bike started to feel a little funny while pedalling.  I was able to get home, and it seems like there's a tiny bit of play so that I can wiggle the cranks / chainrings around side to side a bit.  I tried tightening the cranks a bit, but they felt plenty tight already . . . anyone know what could be wrong?

velocistar237

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Re: Bike Experts - Loose cranks/bottom bracket?
« Reply #1 on: January 11, 2013, 10:14:17 AM »
The bottom bracket can get loosened and develop a wobble. There are several types of bottom brackets, so if you fix it yourself, you would need to figure out which type and which tool. The Park Tool Big Blue Book is a good reference to have.

Russ

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Re: Bike Experts - Loose cranks/bottom bracket?
« Reply #2 on: January 11, 2013, 10:16:36 AM »
I'm guessing that when you move one crank the other moves with it; is this correct? If so, either your bottom bracket cups are loose (as velocistar said) or the bearings are toast.

Matt K

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Re: Bike Experts - Loose cranks/bottom bracket?
« Reply #3 on: January 11, 2013, 10:27:14 AM »
If you have a local bike co-op, bring it in there.

Failing that, bring it to your local bike shop and ask to watch while they fix it. (It should be a one minute job, but call ahead as there may be a long line of people who dropped their bikes off before you.) They'll be able to show you how to do it, and will happily sell you the tool you need to do it yourself next time. Yes this costs more than you-tubing, but it ensure you get the right tool, and know exactly what to do on your sepcific bike. I find most bike mechanics are an awesome source of local in-person knowledge.

Pro-tip, wash your bike before you bring it in. Bike mechanics work on dirty nasty bikes all day, bringing yours in clean immediately put you in their good books.

GuitarStv

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Re: Bike Experts - Loose cranks/bottom bracket?
« Reply #4 on: January 14, 2013, 07:10:57 AM »
Well, I took it down to the local bike shop.  Fortunately all that was needed was a tightening of something with a funny little wrench (looked like a sickle with a tooth on the end) and a regular looking wrench.  Took him two minutes, and he didn't charge me for it!

The bad news is that while that bike was out of commission and the weather was nice (balmy 12 degrees C in January???  Holy Global warming batman!) and slush free I started riding around my fancy new touring bike and am now officially spoiled.