[CR]Bio-Pace

(Example: Racing:Wayne Stetina)

From: <OROBOYZ@aol.com>
Date: Wed, 31 Jan 2001 11:42:12 EST
To: wspokes1@hotmail.com, classicrendezvous@bikelist.org
Subject: [CR]Bio-Pace

I must abstain from the uniform heckle that these much maligned chain rings receive.. In fact, let it be noted that condemnation of these chain rings is universally conformed to by all with-it cyclists..

BUT let's review the theory that propelled Shimano to spend so much time and money promoting BioPace..

It was decided, in the Shimano R&D department, that the natural circular pedaling action didn't use all the muscle systems in the legs properly.. That some muscles are stronger and others weaker or in a position not to be effectively used in the pedaling action. The down stroke was the strongest and the back of the stroke was the least useful. Rather than oblige riders to learn a difficult technique (learn Spinning, acquire "Souplesse", or whatever) they decided to design chain rings that optimized the down stroke and minimized the rest.

The Biopace chain rings are elliptical and "lobed" to emphasize the power stroke and "slip through" the back stroke. (Incidentally, elliptical chain rings are an old concept and have been revisited many times in cycling history.) In use, the BioPace chain rings cater to novice riders and/or tourists who pedal more slowly and tend to put more emphasis on the down stroke. This obviously was the anathema to experienced riders who had been constantly urging neophytes to pedal "correctly."

Back in the late 1970s, I receive from Wayne Stetina at Shimano one of the first sets of BioPace chain rings brought into the USA .. He wanted me to ride them and provide feedback. I mounted the crank set on my McLean touring bike and after rode for a few months (back in my more active days!) I noticed the odd loping effect, bobbing almost, as one pedaled but adapted to it quickly. Eventually I got to not mind that effect at all and maybe believe it wasn't all that bad.. But the BioPace definitely doesn't encourage high rpm pedaling and perhaps encourages chugging along in bigger gears than one ought to be using.

So, historically they are interesting, but functionally BioPace was probably a hindrance to advancing in technique and pedaling style.. But also not a total joke to my view....

Dale Brown