Here's an edited preface to my question (from Wikipedia): The Shimano Octalink system provided a greater contact area between crank and spindle (than square taper), so it had a stiffer interface. Since Octalink is proprietary many competitors have adopted the square taper and ISIS designs as an alternative. In use, Octalink has been shown to loosen because it is not a taper-fit but merely a tight spline fit. Reverse torque loads can cause the crank bolt to undo, and the crank can be irreparably damaged if this is not checked.
Here goes: The bolts on my Octalink-equipped fixed gear bike cranks loosen after any ride. I keep a fat-handled hex wrench handy to tighten them. I have not torqued them to spec but the big hex gets them very tight. I greased the bolt threads when I installed them. (Like I do with almost all fasteners.) So, would you clean the bolts and use Blue Lock-tite on the threads? Or just clean the threads? Or just keep checking them?
Has anyone else noticed this problem? If you ride Octalink you might pay attention to this...
Unless you have a 2 foot
Unless you have a 2 foot long hex key, you aren't torquing down to the 40 ft-lbs needed. I have an 8mm bit and torque wrench if you'd like to borrow them.
I don't think greasing the threads would affect it (it's steel on steel, so technically no grease is needed, maybe a single drop of oil to prevent rust)
Like with FSA cranks, You
Like with FSA cranks, You should loc-tite the crankbolts. This lacks a taper feature which is wrong IMO. The fact that your crank arms are loosening up suggests that you may have already created some play between the the splined teeth. Either way, Loc-tite is what FSA insists to be a mandatory part of the installation because their design suffers in the same way without it.
danger!!!
fixed gear = reverse torque, so that's what's making it loose.
http://sheldonbrown.com/brandt/loosening-cranks.html
I know with square tapers, once it "goes loose" and you retighten it, it's simply a matter of time before failure.
http://sheldonbrown.com/brandt/installing-cranks.html
Thanks
We're in the early stages of failure if any...I want to nip this in the bud before damage occurs. I'll torque 'em and use a drop of Blue Lock-tite.