Kind of makes one wonder about the alloy crank bolts which I seem to recall being sold at the height of lightweight mania in the late 70's/early 80's. I think the procedure was to tighten the cranks with regular steel bolts, then remove them and install the alloy ones for weight savings. Makes you wonder if bolts too weak to tighten the cranks were strong enough to keep them from loosening. And what if one had to tighten a loose crank on the road?
Regards,
Jerry Moos
-----Original Message----- From: Brandon Ives [mailto:monkey37@bluemarble.net] Sent: Monday, May 14, 2001 12:18 PM Cc: classicrendezvous@bikelist.org Subject: [CR]Bad ideas
OK something on this list I've seen touted as a good idea really isn't and I need to speak up about it. DO NOT EVER ride a crank without the crank bolt if you want the crank to be mounted ever again. DO NOT EVER ride a crank without a bolt unless trips to the hospital are a fun thing in your book. The first point first, a tapered steel spindle and aluminum arm relies on a swaged fit to stay tight. To remove this crank without "pulling" relies on loosening the swaged part but loosening the fit requires that you "round-out" the arm just a bit. Many people on the list will say, "I've done this plenty of times" I'm sure you have and you've damaged your crank each time. Don't take my word about it talk to your local mechanical or materials engineer and ask about swaged fits with dissimilar metals. Personally I've seen at least a few dozen cranks ruined by people who "knew what they were doing" over the years in the shops I've worked in.
My second point is also based on experience from people who "knew what they were doing." Sure I've only seen a few incdents, but what I've seen in at least on case means that gentleman can't ride a bike hard again since he has so too little achellies tendon and too much scar tissue. Also broken collarbones can happen when you "just fall off." When the crank comes loose it's just like the arm breaking as far as control of the bike is concerened. Sure many people use chairs with casters as ladders, but that doesn't make it a good idea. The same goes with riding unbolted cranks.
Sorry if this post is a "bummer" but I really don't want to see anybody get hurt or destroy more "classic" parts by doing something silly. Remember most accidents happen to people who "know what they're doing." enjoy, Brandon"monkeyman"Ives
"Nobody can do everything, but if everybody did something everything would get done." Gil Scott-Heron