Originally Posted by
Bjenkins
Hi Scott,
I went all over the web before I asked this question of the group. I've downloaded probably about a dozen vintage Motobecane catalogs and a couple of owner's manuals. Actually, you'd think that there would be a few shop manuals floating around out there but I couldn't find any. The closest thing to manufacturer's instructions I can find is, "The crank assembly should be cleaned, inspected and lubricated by your Motobecane Dealer every 1000 miles, assuming average conditions". Great for drumming up business for the dealers, but not very informative for the owner.
Thanks for your info!
Sounds like you've done your due diligence, then! I honor that and your "first do no harm" attitude.
When I don't know about a particular crank, I tend to "shoot for the middle" -- I'll use a light coating of oil on the spindle and torque to 25 ft-lbs, then see if it stays put after some riding. When re-checking the torque, I use a beam-type wrench that lets me see the torque level where I start meeting resistance. If it resists right away and indicates about 10-15 ft-lbs, then I figure the crank is seated pretty well, and I might only pull up to 20 ft-lbs or so. If the bolt hardly resists at all, then I might pull it all the way back up to 25 ft-lbs and make a note to check it again soon. It should stabilize and not need any more attention after that; higher torque may be needed if it doesn't.