BayAreaUser

I'm changing my cassette(s) to 12-27s given that i will be doing a significant amount of climbing in preparation for the death ride. I'm changing 3 cassettes. On the Madone, the caad 9 -which has 105 components so that's not an issue, and I'm secretly changing my gfs because .. well she could use the lower gear but does not want to admit it.

Currently on the madone i'm running a dura ace 7800 grupo. I can however find 105 cassettes (take offs) for 35 bucks locally. This sounds a lot better than upgrading to 7900 units for $160+ (if that).
Will i be able to run a 105 cassette without major problems with the dura ace 7800 chain and derailer? I'm pretty sure i can, but just wanted confirmation.
I searched and could not find a yes or no answer. I also have the compatibility graphs, but i can't understand them to save my life.

Thanks.

NathanC

Yah.

eric01

10 speed Shimano cassettes are interchangeable across the board. Only difference I'm aware of are some Easton freehubs which -- for whatever strange reason -- are minutely different and are specifically designed for only dura-ace. But that's a very rare anomaly.

Otherwise, you're doing what I've been doing for years. Train on 105 -- steel cogs, cheaper, longer lasting. Race on Dura Ace. More expensive, lighter and slightly less durable due to Ti cogs vs steel cogs.

BayAreaUser

Thank you guys!
That's the answer i was looking for =)
I was just unsure whether 105 cassettes would be compatible with 7800 chains or even 7901 chains down the road.
Thanks again!

ruindd

I "think" the new 7900 hubs will only take shimano cassettes (i.e. you can't use sram), but other than that sram/shimano 10 speed is all interchangeable. So you can go 105 cassete on a (non-7900) dura ace hub with a rival RD and ultegra crank.

NRRider

Don't forget to check your chain length after you replace the cassette. I learned that the hard way and ended up with a costly wheel repair due to the RD hitting the spokes.