because I'm stupid tell me what rear mech I need.

I have a new Niner 29er full suss frame. An RIP 9 to be exact. 120mm travel in the rear.

I plan on running it with a 39/22 10 speed chainset and an 11/32 cassette.
I currently have a sram x9 medium cage RM that was going to go on it. But I fancy one of the type 2 new ones, so was wondering, do I need a long or medium cage? The medium would be fine on the 11-32 but does the fact that its full suss complicate the issue?

Thanks for any help you can offer.

If I plan on putting a larger ratio cassette on the back – say 11-36 does that make a difference? That would need the long cage correct?

On a slightly different note, would I be able to use a 3×10 front mech shifter with a 2×10 front mech?

I run a medium cage on an 11-32 cassette with a triple and it’s fine (Shimano though)
I also have a 3sp shifter and a double chainset and that’s fine too, just with a ‘dead shift’ ie. the final press down doesn’t do anything. (Road bike though)

I think you need a 2 speed front shifter with a double as the spacing is different (I Think!).
I also believe the rule of thumb is 2 rings at the front medium rear mech, 3 rings for a long. My bike came with a medium and I have an 11-36 rear mech!

Jay

The things that strike me are:

1. 39/22 is quite a big gap – 17 teeth is a lot in a single jump. 14 or fewer is generally a lot better. Many are 38/26 this is pretty smooth. So have a think about this before doing it.

2. With such a big difference you may find you need to use a triple front mech as I GUESS the max capacity of the double front mechs are less than 17. Capacity being the difference between big and little.

3. If you are running 10 speed why not get an 11 or 12/36 cassette which will resolve the issues on the front but give a similar range of gears.

4. Rear mechs have two numbers associated with them. One is a Max which relates to the biggest sprocket they can take. The other is capacity which is the total difference in teeth between the biggest and smallest front and back added together. If you are running a 36 cassette and a 12 tooth difference at the front you should be fine with a medium. Triple chainsets with a 36 on the back will need a long cage rear mech.

Shimano front shifters are switchable between double and tripple – not sure about SRAM.

HTH

Hi, you can run a double set up with a triple shifter from sram, I switched my nerve am from a 3×10 to 2×10 and used the same mech and shifters for both.

Sorry, my mistake, its a 39/26!
Does that change anything? So I could put a medium on no problems?