Originally Posted by
bigvegan
There's also a significant difference between tightening the cranks on a road bike and on a fixie, due to the different stresses involved.
If you're using a fixie on the street, you're going to be putting substantial pressure on the crank in both directions, so you're going to need to tighten the crank bolts a lot more often, especially if you're a heavier rider.
Don't crank them down so tight you split the crank, but do tighten them back up after every ride or two.
Actually if you have to tighten them after installation it to late the damage is done. steel against aluminum the aluminum is ruined or the splines on in the cartridge have been stretched out.
you may get lucky on a tapper crank like I did on my old motobecame vitus tubing supper touring able to feel it get loose take the arm off clean it up loc-tite the nut on.
a fixie does not make a defference ok a fit is a fit, if it came loose you did something wrong or it was already damaged prior to installation. I really do not want to go into the actual physics of why your statement should be reconsidered
but it simple physics. What you want is a one peace forged crank arm for the chain ring side Right side. The pressed fit ones will work loose Chain ring not the crank arm. not always but I have seen it.
As far as needing a torque wrench that's the difference between a mechanic and a parts changer. And understanding torquing a used crank 35 nm factory standard may ruin it.
If the crank set comes loose something was wrong with the installation. if chain rings come loose measure the bolts I get the shorties in that are .25 mm to long and I have to grind them down. very common on that big name fixie company.
as far as stress trust me the only thing that gets tweaked is the frame nothing like old steel.
FlatsFixed