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jonathan creason
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Crank issue
05/27/13 at 6:45pm
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During a ride on Friday I noticed my left crank had worked loose.  I didn't have any tools with me at the time, so I hopped off and pushed my bike out.  Today the crank came loose again and the bolt backed all the way out before I noticed.  I lost the bolt somewhere on the trail and never was able to find it.  After looking the crank over I noticed the sides had been wallowed out some, which I guess led to it working loose.  Can I assume the crank is pretty well fubar?  If so, anyone have a single speed crankset they would let go of cheap?
  
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Banjopickin
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Re: Crank issue
Reply #1 - 05/27/13 at 7:50pm
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I had a similar issue where the non-drive side crank arm stripped out on the spindle splines. It wasnt completely stripped so I lined it back up took a rubber mallet to it and got it back on, then torqued the pinch polts down to recommended specs. No problems 5 months later. I dont know what kind of cranks your running but make sure those pinch bolts are tight before and after each ride. If your running a square taper or some other configuartion the same applies. Before buying a whole new crankset see if you can find a new crank arm instead and just swap it out. If its a combo of bottom bracket and crank arm that are shot then get a new set. Hope that helps
« Last Edit: 05/27/13 at 7:52pm by Banjopickin »  
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Advocat wrote on 08/22/13 at 5:16pm:
...packin some Chub in the back of the pick-up.


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jonathan creason
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Re: Crank issue
Reply #2 - 05/27/13 at 10:40pm
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I think it's just an issue with the left crank arm, so just replacing it may be the best bet.  Anyone know what the standard length on a monocog is?  175mm?  Also, would that come with a new retention bolt, or would I have to order that separate?
  
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twinsdad
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Re: Crank issue
Reply #3 - 05/27/13 at 10:53pm
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Maybe see if a shop has a pinch bolt before replacing the whole crank arm.....
  
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lv2mtnbk
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Re: Crank issue
Reply #4 - 05/28/13 at 12:58am
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I had the same issue too. Use some non permanent Lock Tight on the bolt when re installing.
  
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GEAUX TIGERS!!!
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jonathan creason
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Re: Crank issue
Reply #5 - 05/28/13 at 1:08pm
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Quote:
Maybe see if a shop has a pinch bolt before replacing the whole crank arm.....


I thought about this, but I'm concerned the crank arm is too far gone to salvage.  I did tighten the bolt before my ride yesterday and it worked loose again on me, so I figure there's some play in there even when things are snugged down.
  
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Banjopickin
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Re: Crank issue
Reply #6 - 05/28/13 at 2:16pm
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What type of cranks are you running. If its continually working loose it may be in the bottom bracket. Just a thought.
  
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Advocat wrote on 08/22/13 at 5:16pm:
...packin some Chub in the back of the pick-up.


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jonathan creason
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Re: Crank issue
Reply #7 - 05/28/13 at 2:29pm
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They're TruVativ (made by SRAM, right?) 5D's.  I guess it potentially could be the bottom bracket (hope not).  My main reasoning for assuming it's just the crank arm is that I can see a couple of areas where metal has been moved inside the spindle interface.
  
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jonathan creason
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Re: Crank issue
Reply #8 - 06/26/13 at 8:33pm
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Quick update.... I bought a new crank arm, and it worked loose on the first ride.  Looks like it may be a bottom bracket issue.
  
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