How much torque?
03-14-15, 07:09 PM
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How much torque?
I anticipate servicing some bottom brackets on a few bikes in the upcoming weeks. I have a Schwinn Super Sport, a Raleigh Grand Prix, a Trek 520 and a Motobecane Grand Touring, all late 70's - early 80's vintage. I want to know how much torque to apply to the nuts when reinstalling the tapered cranks. Are there manufacturer's specifications out there, or is there a "generic" sort of torque value? Thanks for any help.
03-14-15, 07:25 PM
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About 30 Lb-Ft.
03-14-15, 11:16 PM
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I tell my torque wrenchless customers (for many years) that 30 ft/lbs is pretty much all one's hands and wrists and much but not all one's upper arms strength. This is not a hard rule but gets across the need to apply some real, but not all, arm strength. Andy.
03-14-15, 11:41 PM
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30 - 40 ft-lbs basically the weight of an average bike at 12 to 15 inch radius. So you can calibrate your force by getting a feel of your bike's weight, and using a 12 to 15 inch long wrench. That will be pretty close. It is FAR better to run over to Harbor Freight and purchase a $10- torque wrench.
03-15-15, 11:22 AM
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03-15-15, 08:17 PM
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Thanks for the help. I do plan to purchase a torque wrench or borrow one from my mechanic friend - the one who has ALL the tools.
03-16-15, 04:22 PM
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