Osymetric Rings - ramp & pin model shifting problems

Discuss light weight issues concerning road bikes & parts.
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Posts: 5
Joined: Thu Aug 04, 2011 3:22 am

by johnnyb2

Just upgraded from the old Osymetric rings to the ramped & pinned versions that were released earlier this month. Has anyone else installed and got these working?

Ultegra Di2, SRM7950, KCNC chainring bolts.

Finished the installation & I can't get the front derailleur setup properly. Either 50/11 drops the chain off the outside of the large chain ring (outwards) or selecting 50/25, 50/23 & even 50/21 drops the chain from the large front ring to the small ring (inwards). Going back to the old rings everything works fine again.
Didn't use the front derailleur spacer on these or the older style rings, the 50 tooth doesn't need the clearance.
Using Ultegra Di2 so there is no way to spread the derailleur cage at the rear to provide more clearance for the chain, but i'm puzzled why this would be so different, the rings look identical in shape.

The only difference i can see is the new rings don't use circlips to space the 38T chainring - but the instructions also don't have any mention of these so i'm assuming circlips are only for the older generation rings. This would give me an additional 1mm space between the chainrings, but i can't see how this affects my problem.

Not sure how to explain to my NYE guests what the bruises on my forehead are from :doh:


Posts: 271
Joined: Wed Mar 31, 2010 3:37 am

by natefontaine

Can you post a pic? In the big ring looking down from the front, and in the small ring looking down from behind the derailleur.

Sent from my SPH-L900 using Tapatalk

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