-
Help please!
I've got a Stronglight 93 drive side crankarm mounted on a frame and I can not get the crankarm dustcap removed. The cap has a stripped allen hole in the center (came to me that way, really). So far I've tried:
Penetrating oil heat on the cap but not on the aluminum arm punch with a hammer to try and drive cap to turn which ended up actually tearing the steel cap....
.... all to no avail.
Any ideas, tips, techniques or magical spells I can use to get this very stubbern cap off?
Ammonia...first clean out the penetrating oil (that works on rust, but rust is not your main problem, aluminum corrosion IS) and then soak it in pure household ammonia for as long as it takes. The suggestion about an "impact" force to loosen stuck components is a good one IMHO, but you may not need it if the ammonia does the trick. You might need to follow the ammonia with a penetrant and/or gentle heat (from a propane torch) and you should try to heat the ARM , not the CAP (aluminum will expand much faster than the steel cap). I've always prevailed against any frozen component, but a couple of them have been such monumental struggles that I only kept fighting for the sake my own ego, there wasn't any way to justify that much sweat for any crummy bike parts.
I just can't stand letting rust win :)
Courage!
Alan Goldsworthy
San Francisco, CA