[Rendel Harris]

Just acquired a very lovely 2014 Specialized Roubaix Pro SL Dura Ace with an 11-28 rear cassette. I know 28 is the maximum size specified by Shimano for this groupset, but equally I know one can usually easily run a few teeth above the official limit. Just wondering if anyone else has run a 30 or 32 tooth big cog on Dura Ace of this vintage? Any advice much appreciated.

Topic

[Dnnnnnn]

Rendel Harris wrote:

Rendel Harris wrote:

I have my doubts it will cope with a 32

I’ve tried an older short cage 105 mech (5500 series, I think) and found this. No problem with 30 but 32 was a sprocket too far. Adjusting the B screw didn’t seem to help much – there was just too much chain for the short cage to take up.

[Rendel Harris]

Yeah, bit of equipment vanity

Yeah, bit of equipment vanity I must admit to keep a Dura Ace rear to match the rest of the groupset… maybe somebody should sell Dura Ace stickers to go on Ultegra derailleurs…

[Simon E]

A long cage mech would be the

A long cage mech would be the ideal solution. If it was me I’d fit it anyway and leave it on there.

[Rendel Harris]

Thanks, tried it with a 30

Thanks, tried it with a 30 from another bike and it works fine. From the look of the setup I have my doubts it will cope with a 32 but I have a spare Ultegra long cage I can put on if heading for the really steep stuff. Cheers for the advice.

[Simon E]

A 30T cassette will work fine

A 30T cassette will work fine, Shimano are known for their conservative compatibility figures. If there is plenty of adjustment on the b-screw then 32T should be no problem. Here’s one bikeradar thread for example.

If that’s not the case you could possibly look at adding a Wolf Tooth RoadLink extender.

[Author]

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