saw this today, thought it might be of use for a retro build in the edinburgh area
http://edinburgh.gumtree.com/edinburgh/29/30871229.html
http://edinburgh.gumtree.com/edinburgh/29/30871229.html
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LeeDevelopment
Old School Grand Master
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konahed":213m764y said:
For buggering up your knees, yeah!
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LeeDevelopment":2s5k2aw7 said:konahed":2s5k2aw7 said:
For buggering up your knees, yeah!
That's not quite true... well not for me. I found them fine under general use.
I think stigma mainly killed it off.
FluffyChicken":1oh9ea6n said:
x2. I have 'em on one of my road bikes and never noticed a difference.
Sheldon Brown didn't mind 'em either
they were ok to use, better for slower grinding type riders, felt pretty weird if you've got a fast cadence. the difference in height of the chainring as it rotates meant you had to move your front mech up the seattube a fair amount & the shifting suffered because of that.
they seem to re-appear every few years.. what comes around eh
they seem to re-appear every few years.. what comes around eh
velomaniac
MacRetro Rider
The late great Sheldon Brown made an interesting observation about biopace which he quite liked.
He said that as the lengthways axis of the oval rings was in line with the cranks, when you started to power down on the lever with the arm at its heighest point the gear was high but as you reached the horizontal the gear was slightly lower helping to deal with any off road loss of traction at this less powerful point in the stroke.This idea can be helpful in single speed where its all about power and traction.
As for damaging your knees this came from the road bike community who had tried oval rings long before but set at 90 degrees to the cranks and yes knee bother did result. Biopace was based on a great deal of research into ergonomics but the idea that oval rings was bad was now too deeply engrained and the idea had to be shelved.
I had a biopace chainset with Sakae rings in the past and yes suntour did its own version.
He said that as the lengthways axis of the oval rings was in line with the cranks, when you started to power down on the lever with the arm at its heighest point the gear was high but as you reached the horizontal the gear was slightly lower helping to deal with any off road loss of traction at this less powerful point in the stroke.This idea can be helpful in single speed where its all about power and traction.
As for damaging your knees this came from the road bike community who had tried oval rings long before but set at 90 degrees to the cranks and yes knee bother did result. Biopace was based on a great deal of research into ergonomics but the idea that oval rings was bad was now too deeply engrained and the idea had to be shelved.
I had a biopace chainset with Sakae rings in the past and yes suntour did its own version.
