Cassette/RD question

All 10s shimano shifters, derailleurs and cassettes are compatible with each other. Your wheel has an aluminum freehub body, which shimano says needs deeper splines than the steel bodies on other hubs (deeper splines to increase the area the cassette presses against). I've used Ultegra cassettes on hubs specified for D/A only without incident, even though it's out of spec.

I am not clear, I also in attention thread insert helicoil

That sounds like some real BS... the carrier design is the same between Dura-Ace and Ultegra (and I would think 105 as well), so designing a hub working only with D/A and not Ultegra would be technically impossibly... plus, Ultegra cassettes are more durable than Dura-Ace... and cheaper to boot.

+1, this is my understanding as well. I don't think you'll have any issues other than perhaps having to have the derailleur adjusted.

I just put an ultegra 12-27 on my brothers bike, he runs a 105 for a rear derailleur. No issues.

I just got some Easton EA50 SL wheels and was trying to put a 10 speed 105 cassette on.  I could not get it to tighten up all the way (not sure if this is the same problem they are idicating).  I just went to the LBS and got a small spacer that goes on before the Cassette and problem solved.  Perhaps that is all that is needed.  I realize my wheels are a lower end model but it's worth a try.  He didn't even charge me for the spacer so that's cheaper than a new cassette.

And the Ultegra 10sp RD should work fine with the DA cassette if you do have to go that route as others have indicated.  Check this link out if you like...
http://www.shimano.com/publish/content/cycle/saus/au/en/technical_service/compatibility_charts/road_compatibility.-MainContent-0002-DownloadFile.tmp/Rear%20drive%20road%20compatibility.pdf.pdf


Edited by jaredfore 2009-08-17 9:25 AM

The only issue that I could possibly see if some of the components are older then others. First, is everything 10spd. Second, DA/Ultergra/105 components have all gone through design changes in the past 5 years. Even not all DA 7900 series components are not compatable with DA7800. Ultegra and 105 have also been upgraded in different years.

I would check with Shimano directly to make sure what is compatable across the three lines.

Thanks for the feedback.  The issue is with "spacing", so I'm wondering if just a spacer will be needed in order to get these wheels to work with his existing 10spd 105 cassette.  According to the Easton rep, the 90 SLX's rear hub works with some of the Ultegra 10spd, and only about 25% of the 105 10spd cassettes.  My concern, was if he does need to swap out the cassette...would it be compatible with his 105 RD. 

The cassettes and derailleurs are all compatible. It's the wheel's cassette body that may/may not work with certain group cassettes. If you can get it to fit the wheel, you can use cassettes and derailleurs in any combination.