Shimano Biopace Cassettes, highly recomended training aide

Page may contain affiliate links. Please see terms for details.
Good morning,

A few months ago I found some NOS Biopace cassettes, they are similar to the Biopace chainrings but a lot rarer. Like the chainrings the cassette sprockets are oval shaped, but unlike the chainrings which were general purpose, the cassettes are aimed fairly and squarely at road racers as a training aide.

B2.jpg
As the chainring and sprockets are not the same size the gearing is continually changing slightly during the pedal stroke, the hard point is not always at the 12/3 o'clock position but changes as the position of the larger sprockets moves relative to the pedal stroke. This continuously varying load makes riding harder as you automatically "move up and down a gear or two" without actually changing gear so the legs never get into a rhythm which can let inertia take over and the legs rest just a bit.

At least that is the theory, but surprisingly it actually seems to work!

As the sprockets get smaller they become rounder and an 11t sprocket is as pefect a circle as a normal cassette, why this is so it unclear, unless the intent is to prevent riding in too a high a gear and damaging the knees.

To be completely clear these cassettes are not more efficient than a normal cassette, they are deliberately less effecient in a controlled and understood manner and are intended to producing better cycling legs for use with normal cassettes.

Bye

Ian
 
Last edited:

ColinJ

Puzzle game procrastinator!
At least that is the theory, but surprisingly it actually seems to work!
Yes, it is a surprisingly effective innovation.

The downside is that it only really works one day a year!
 
Good afternoon,

I have just spoken to my mate Donald and he is getting Elon to make them and all Shimano cassettes wil be subject to a 50% tariff and as England is the zeroth US State that will apply here to!

I have also just been on to ChatGPT and; (this really is true, trust Emma [Baby Spice]) This really is the response trust me, I would lie to you, but I am not!!!

Biopace cassettes refer to the special cassettes used in bicycles equipped with Shimano's Biopace chainrings. Biopace was Shimano's proprietary oval-shaped chainring design, introduced in the 1980s. The idea behind Biopace was to improve pedaling efficiency by altering the traditional circular shape of the chainring. The oval shape was intended to optimize the force applied to the pedals during the most powerful parts of the pedal stroke and reduce strain during other parts of the stroke.

@Drago Where does this this leave the True Facts About Chris Rea thread?

Bye

Ian
 
Last edited:
Top Bottom