Bicycle Mechanics - Crank Arm Threading - Both sides the same?

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Surlyrider
07-19-11, 01:14 PM
I need to remove my crank arms to replace my BB. Are both the crankarm bolts threaded the same? The drive side is standard left = loose right = tight. is the non drive side crankarm bolt the same? this is my first time removing them. Thanks for any help.

mechBgon
07-19-11, 01:28 PM
That's correct, both crankarm bolts are threaded the same. Some bolts have a built-in washer, but if not, make sure you remove the washer from the crank after the bolt's out (and this includes Octalink, where the washer's very easy to overlook). I still remember the first time I ever pulled a square-taper crankarm as a kid, and learned this lesson the hard way.
Surlyrider
07-19-11, 03:36 PM
Thanks, perfect, and I was able to remove with no problem (well, OK, it was really tight, but I was able to remove it). I replaced my bottom bracket and reinstalled everything. Great forum and thanks for the response.

Jeff Wills
07-19-11, 06:35 PM
Thanks, perfect, and I was able to remove with no problem (well, OK, it was really tight, but I was able to remove it). I replaced my bottom bracket and reinstalled everything. Great forum and thanks for the response.

Make sure the crank bolts are tight... really tight... before you ride the bike. They should be torqued to 25 to 25 foot-pounds. This is more than most people can exert with the standard crank bolt wrench. More cranks are ruined by the bolts loosening and the cranks getting distorted.

Good info: http://www.parktool.com/blog/repair-help/torque-specifications-and-concepts