Osymetric chain rings

Do you use them?

12 messages
31/07/2012 at 12:08

I was reading about Osymetric chain rings today. I thought I would find out if many of you use them and spread a bit of knowledge if you have never heard of them.

Wiggo, Froome and others all use these. Apparently they allow you to produce less lactate. They are basically a cam which give you a higher gear when you can use your big muscles to most effect i.e. 1 o'clock to 5 o'clock and a lower gear when you can't use these big muscles.

This provides more info including a paragraph on tri/duathlon benefits:



TheEngineer    pirate
31/07/2012 at 12:13

I have some interesting scientific papers on them if you'd like to PM me your email address, mate. Particularly keen on getting some myself when the budget allows. My only reticence is that they may require some fiddling with derailleurs to avoid fouling - but I'm sure that's not too much trouble to sort. 

They came up in conversation in the Bike Numpty thread too recently.

31/07/2012 at 12:28

Yeah it's the derailleur fiddling that I find quite offputting to be honest. Apparently it's easier on shimano and a mission on SRAM. I'll drop you the email address in a pm. Thanks for sharing

Didn't know about the bike numpty thread. Will check it out!



31/07/2012 at 12:33
I looked at them when I had my TT bike built. And the guy who built it said the cost wasn't justified for a fat old bloke !

My SRAM looks identical to the Ultegra on my other bike. Seems easy enough to keep in trim
31/07/2012 at 12:53

Dave when you fit the ring you need to raise the front derailleur and often it needs to go above where it is designed to go. Apparently it's a bit easier on some of the shimano setups. The cost seems to be about 100 quid per ring. I was wondering if maybe having a big osymetric ring and a small round ring up front might be a good idea. Anyway it's not something I will do any time soon myself but was keen to see what others thought of it.

31/07/2012 at 12:56
I have a carbon frame so the mount could have been fitted anywhere. More a case of where the mount was brazed on when it was built.
31/07/2012 at 13:12

my understanding is that you have a fixed brazed on point which was not situated with an osymetric ring in mind. So apparently this can make it awkward to get the FD set up. I may well have that all wrong though

31/07/2012 at 16:07
They aren't compatible with new SRAM red black chain rings unless you machine out the internal part that sits behind the drive arm on the crank,
Doozer.    pirate
02/08/2012 at 07:03
I use Q rings not osysemetric. Not quite as extreme but still add some efficiency savings in my opinion
02/08/2012 at 09:13

these and sky kit will be the best sellers of 2012/13


The Disco kit and cadence of 110 is dead - long live the Wiggo.

05/08/2012 at 19:35

Didnt Shimano do some thing similar many years ago ( Biopace) but stopped doing them due to people having knee problems?

TheEngineer    pirate
05/08/2012 at 21:23

Chris, yes they did. Except they put the areas of high load in the wrong place!

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