Bio-Pace and a state of MY mind

[Not the Slowest]

Okay, I like older bikes, maybe vintage but I also LOVE my Seven Titanium bike.

In anycase almost all my older bikes come with some configuration of a Bio-pace crank. In this case it's a triple and I use it for Brevets, touring and almost all my commuting, gearing is 50-46-28.

Here's the catch. I also race track and this off season am working on some speed work.
WITH the Bio-pace crank I feel that there is a gap feeling as if one leg in HIGH cadence is not pushing or pulling the pedal.

I do understand the design, concept and error in the chainring, but is it my imagination?

My goal is to stregthen my Leg speed/strength and I am thinking a normal configured ROUND chain ring may be better suited for me.

I have no issue with the crank and have done maybe 15-20,000 with it, but do feel this shortcomng effects my leg work on the track.

Thoughts?

Thanks Robert

[christian]

It's not you. Bio-pace was designed for a specific cadence, maybe 75-80 rpm. As I recall, Bio-pace II was less bio-pacy and allowed for a faster cadence. But for spinning drills, yeah, you need to go 'round.

[christian]

http://sheldonbrown.com/biopace.html

[Not the Slowest]

Thanks Christian,

Why do I bother posting, I should just send you the emails, lol.

I'm at the stage that I need to tweak many things for the track and it was suggested that I shorten my Road cranks from 175 and perhaps lengthen by track cranks which are now 167.5. Part of all of this is muscle memory and kind of using my road work for training for the track races.

Okay, I love road work, climbing touring etc and don't want to go too crazy, but I always felt something at times was off if I powered up my crank in say Central Park. Trying to keep to a certain gearing and cadence is impossible.

Blah, Blah, Blah.

In anycase since I do so much commuting I guess switching the crankset on this bike makes the most sense. now I have to find something round and maybe a step down in crank lengnth to 172.5, so I can benefit more from the commute and not lose leverage for climbing.

Robert

[fiamme red]

I have Biopace chainrings on my MTB, which I use with Marathon Supreme tires on dirt roads and easy trails. My average cadence is about the same as with round rings, about 90-95 rpm. Biopace makes very little difference for me.

[christian]

M - that's interesting! I have Bio-Pace rings on my early 1990s Scott Comp mtb and I find my cadence to be consistently low and constant on that bike; I wonder if it's a combination of 175mm cranks and placebo effect! :)