RE: [CR]Bad ideas

(Example: Framebuilders:Bernard Carré)

Date: Mon, 14 May 2001 14:44:56 -0500 (EST)
From: "Brandon Ives" <monkey37@bluemarble.net>
To: "Moos, Jerry" <jmoos@urc.com>
Cc: classicrendezvous@bikelist.org
Subject: RE: [CR]Bad ideas
In-Reply-To: <ABC4A5183996D411BF92000629EEABAD3662AF@mail-server.urc.com>


If the installation is correct the first time and the cranks are correctly swaged on it souldn't be a problem unless the bolt starts coming loose. Alas, these bolts came loose regularly on many BB spindles. I've acutally used the alloy and Ti ones quite a bit in the past and the trick is to use a thin split washer over the flat washer. With this method I've never had a problem. The point you make about tightening on the road is a valid fear since I've had a Ti bolt round out trying just that during an MTB ride. This is the reason I don't use these bolts much anymore. enjoy, Brandon"monkeyman"Ives

"Nobody can do everything, but if everybody did something everything would get done." Gil Scott-Heron

On Mon, 14 May 2001, Moos, Jerry wrote:
> 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