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Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

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Old 05-07-06, 12:28 AM   #1
Illah
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Loose and/or wobbly pedals?

So I've tightened the 8mm nut as tight as I can, yet there's still some wobble in my pedals/front chainrings. I've looked really close and it seems like the bottom bracket is stable...it's just the pedals/chainrings that are wobbly, not the axle itself. Tomorrow I'm going to take apart and rebuild the pedals/chainring to check for problems, anything I should keep an eye out for while I'm working on the bike? Obviously I'd rather replace a part now than destroy something down the road, so any advice on what to look for would be appreciated.

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Old 05-07-06, 02:05 AM   #2
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Crank's toast? A lot of crankarm bolts are installed too loose. The short 7" Park wrenches aren't long enough to get sufficient torque when installing, you really need a ratchet-wrench or torque-wrench with 12" handle. So the bolt backs due to being too lose, then the crank-arm wobbles and chews itself up on the sharp-corners of teh spindles. The mating surface are mangled and that's it. Even if you were to fully tigthen the crankarm bolt to spec again, the damaged crankarm will still wobble.
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Old 05-07-06, 05:42 AM   #3
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When you take the bolt out check to see if the spindle end is level with the shoulder of the crank. If it is then the bolt was tightening on the spindle and not on the crank. Then you need a new crank as Danno said.
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Old 05-10-06, 10:59 AM   #4
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Quote:
Originally Posted by AndrewP
When you take the bolt out check to see if the spindle end is level with the shoulder of the crank. If it is then the bolt was tightening on the spindle and not on the crank. Then you need a new crank as Danno said.
Can you dumb this down a bit for me I'm gonna grab a pin wrench from Performance today and see if I can fix it since a new crankset is not cheap... It seems the bolt is tightening as far as it can go but it's still not enough, and the bolt 'holder' might need to be adjusted.

Also my other crank (left side) tightens up just fine, but after a few rides it's loose again...should they be loosening up like that? Maybe it's the way I ride? Should I try some loc-tite instead of greasing the bolt?

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Old 05-10-06, 11:08 AM   #5
robthebiker
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check the crankbolt...it may be striped
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Old 05-10-06, 11:26 AM   #6
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The bolt itself and the 'teeth' on the bottom bracket/crank looked good on both the left and right crank...just seems like the drive side isn't tightening all the way?

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Old 05-11-06, 10:54 PM   #7
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Just got the pin spanner and was able to completely disassemble the crankset...I need a new crank I bought this bike used and it looks like the bike shop or previous owner used a BB bolt that was too small for the crank, so it didn't fully meet the crank, it only met in a VERY small area and over time the crank wore down. Very frustrating! Such a stupid error too.

Oh well, I got a bike in otherwise great shape for 1/2 price, but I think next time I'll just invest in buying new to have some protection against ******** mistakes like this...

Any suggestions on a good triple crankset for an ISIS BB on a budget? I'm thinking $100 and under...I know that's bottom end but I just bought a new LCD monitor literally two days ago so that put a fat hole in my wallet

I was looking at this: http://www.nashbar.com/profile.cfm?c...eid=&pagename=

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