Re: [CR]Eccentric 90 degree PMP Cranks

(Example: History:Norris Lockley)

Date: Wed, 06 Jun 2001 08:19:12 -0700
To: GRIFFKS@aol.com, classicrendezvous@bikelist.org
From: "Joseph Bender-Zanoni" <jfbender@umich.edu>
Subject: Re: [CR]Eccentric 90 degree PMP Cranks
In-Reply-To: <68.fb6b2a2.284f59ef@aol.com>


From a mechanical engineering viewpoint, how you get from point A (the BB spindle) to point B (the pedal) of a lever makes no difference other than inducing complex internal load paths in the cranks. This bent crank idea is old however. The same idea showed up in a catalog from the 1930's or so that Leonard Bulger showed me. Old cast iron machinery, like a hand grinder, often has curved cranks, but I believe that was to reduce casting stresses somehow.

Joe Ann Arbor (temperate rainforest), MI

At 06:03 AM 6/6/01 EDT, GRIFFKS@aol.com wrote:
>...........at a local cycle jumble I picked up a set of Italian PMP alloy
>cotterless cranks(new and boxed) that were, I believe, made for a short while
>in the early 80's. they seem well made and accept Nuovo Record or similar
>style rings.
> Have any list members ever owned or tried these unique right angled
>cranks, if so is there any noticeable difference in pedalling or is it just
>design for design sake? I can supply photos if required though Dale has some
>info. on the CR website linked from the "Rarest of Rare" category.
>Finally, are these oddities currently sought after or do they simply remain
>on the back shelf "bought for their novelty value" for another twenty years?
>regards
>Griff King-Spooner (London UK)