The myth of Biopace... Let's discuss

[hamster]

Another silly Shimano gimmick...metric chains anyone..?

 

[We_are_Stevo]

Ahem!

http://www.cyclepowermeters.com/rotor-3 ... -567-p.asp

 

[julesg007]

I had them bitd and my knees didn't get knacker 'cos of them.

Personally I couldn't tell if they any better than normal rings.

I suppose if oval rings were really pants why can you get oval rings on top end road racing bikes?

Perhaps we weren't good enough riders to notice just how good they were!

 

[highlandsflyer]

I hated them with a passion fruit.

Lots of bikes came with them as standard, first thing I chucked off.

Saying that, I have been riding a Clockwork around with a set lately!

 

[kaiser]

Shimano had it arse for elbow. The top of the cam was at the wrong part of the pedal stroke, they tried to smooth out power delivery by increasing the effective chainring size at the low point of the power cycle. The new generation( and possibly egg rings) increase the ring size on the peak part of the revolution. You can shift biopace rings two hole to somewhat but not perfectly replicate this.

 

[We_are_Stevo]

Shimano had it arse for elbow. The top of the cam was at the wrong part of the pedal stroke, they tried to smooth out power delivery by increasing the effective chainring size at the low point of the power cycle. The new generation( and possibly egg rings) increase the ring size on the peak part of the revolution. You can shift biopace rings two hole to somewhat but not perfectly replicate this.

I am so glad you posted that - it was doing my head in trying to remember the other manufaturer to make oval rings...

http://www.highpath.net/

...there's also another, whose rings are almost 'square' but I'll be damned if I can remember that one either! :roll:

 

[kaiser]

O symetric make the squairsh ones as used by Bradley Wiggins amognst others

 

[We_are_Stevo]

Yup, they're the ones...

http://www.ebay.co.uk/itm/OSYMETRIC-CHA ... 2eb7f33ceb

...ta everso,

 

[mikee]

i have a set of sr power rings (i think ) on my 90 al mega xt ,tbh they are more square than oval ,and they seem to inch worm you up a hill ,its a bit like that single speed grind ,where on a grannied bike you'd just spin till you get knackered , but on a s/s you keep going a bit longer ,you know what i mean
this is the same in a pedal stroke ,power slack,power slack , a bit like a GT rts to be honest

some have said fit some of these to an early full suss bike and bounce yourself into the shrubbery , might try it sometime

 

[shogun700]

If I remember correctly, the first generation are heavily ovalized, later versions less so. I think the reports of knee problems came primarily from those who turn high pedal RPM, and this led to the less-oval Biopace 'HP' designs.

I like low RPM and big gears, might be why they work for me.