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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 10-15-11, 09:51 AM   #1
Flying Lizard
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Creaking crank...

I finally seemed to have cured a creaking left crank on my Specialized Globe Pro. After numerous bouts of torquing down, greasing the splines, removing said grease, swearing, praying etc. I removed and cleaned the crank, put it in the oven on 50 degrees centigrade for about half an hour, raised the temp to just under 100 then ran it out to the bike and using a wooden drift, banged it onto the axle and tightened it before it cooled. I've taken it out (warm day) and so far, no creaking... Does anybody else have any similar last ditch methods?
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Old 10-15-11, 10:41 AM   #2
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Um, I'm not sure what your heating of the arm was attempting to cure but if properly re-torquing the crank arm (you did use a torque wrench and grease the bolt, right?) didn't fix the creak, the next thing to look at is the bottom bracket. Chances are your creak will return so you'll get a chance to look there anyway.

Heating aluminum parts to help with press fitting is common with straight bores to avoid gouging the aluminum. With the tapered press fit of your bottom bracket, the heating is unecessary. I doubt you did any harm though as 100 C isn't very hot at all. 175 C would yield some significant expansion of the aluminum though.
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Old 10-15-11, 11:03 AM   #3
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if the taper is wallowed or rounded out then you are buying time. can also buy more time with retaining compound
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Old 10-16-11, 03:25 AM   #4
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Creaking Crank

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Originally Posted by joejack951 View Post
Um, I'm not sure what your heating of the arm was attempting to cure but if properly re-torquing the crank arm (you did use a torque wrench and grease the bolt, right?) didn't fix the creak, the next thing to look at is the bottom bracket. Chances are your creak will return so you'll get a chance to look there anyway.

Heating aluminum parts to help with press fitting is common with straight bores to avoid gouging the aluminum. With the tapered press fit of your bottom bracket, the heating is unecessary. I doubt you did any harm though as 100 C isn't very hot at all. 175 C would yield some significant expansion of the aluminum though.
Hi there, thanks for the post. I think my fix has simply allowed the axle to move a few thou' into the crank arm. I was quite surprised at poor quality of finish on the inside of the crank given the function of the part and of the assymetric nature of the wear, although I guess the power is only coming on for half the rotation. I think the lesson I have learned from this is not to assume that an internet retailer has correctly tourqued down components...(the bike has only done about 1500 miles).
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Old 10-16-11, 03:33 AM   #5
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Originally Posted by reptilezs View Post
if the taper is wallowed or rounded out then you are buying time. can also buy more time with retaining compound
Hi there, thanks for the reply, by retaining compound do you mean Loctite nutloc? I hadn't thought of that, I've never used it on a taper, how is it for removing? I guess it sholdn't be any worse than when it is on a thread. I have kind of resigned myself to replacing the offending article at some point but it would be nice to buy a bit of time, although having said that, at the moment it seems to be ok (fingers crossed).
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