Old 04-23-18, 02:57 PM
Senior Member
Join Date: Jul 2009
Posts: 788
Mentioned: 14 Post(s)
Tagged: 0 Thread(s)
Quoted: 379 Post(s)
Likes: 0
Liked 3 Times in 3 Posts
Originally Posted by Meowriano View Post
Hi, im just curious if anyone knows if the shimano deerhead has enough range to shift a 9spd 12-36 cassette?
Not likely. It's probably not an issue of the in-out range, it's mostly the maximum cog capacity. XT Deerhead RDs have a factory max rear cog rating of 34 teeth, which is close enough probably to fudge. But that rating is only when used with the Shimano SFR dropout, which has a hanger length of 29mm, 5mm longer than the "standard" hanger. If your hanger length is less than 29mm, it's risky. Measure that first. If it's much less than 29mm, I wouldn't even try it.

If your hanger is 29mm or more, it still also matters what chainrings you have. The Deerhead was intended for use with a triple chainring, and as such can handle a 22t chainring difference and a 40t total capacity. If your chainring set has a 16t difference, you're at max capacity anyway, so I wouldn't try it then either.

If your hanger is 29mm or longer, and you have a double chainring set that is less than a 16t difference, then you will have a little spare capacity. In that case, you could run the chain a link short, which might give you the cage swing and jockey wheel gap you need to get on the 36t. You'd have to be very careful not to cross-chain big to big, but you shouldn't ever do that anyway, right? Right?
Ghrumpy is offline