2x9 transmission

[kipperthedog]

I am toying with trying a 2x9 set up insted of my current 3x set up.

I have a 10 speed compatible 38t/24t ring set to go onto an m750 XT crank set, with the remainder being Deore 9 speed. I cant see any problems with this, and drivetraincaculator.com doesn't either. I may come unstuck if the bottom swing Deore front mech won't slide down the seat tube enough to look tidy, but a Deore 10 speed top swing might then be necessary, which shouldn't be a problem either.

Has anyone tried this sort of combination and found otherwise?

I could also just remove the outer ring and run 32t/22t which would keep it on 9 spped rings but the front mech will certainly not go low enough then, and I think it may be lacking at the top end.

 

[Matthews]

Re:

I run 2X9 on both my HT's , 22/36 seems to give a good spread , got bashguards on instead of big ring as a chainsaw blade in the leg is not my idea of fun , if I can't pedal fast enough on the 36 then it's time for a rest as I'm doing 35>40 mph , no problems shifting between the front 2 (ones a xt crankset ,ones a deore crankset both originally 3X9) and use deore steel chainrings as they are cheap and last well , just wound the limit screw in on the front mech and use a standard 3X shifter , did the same to the wifes on one but left the 32 on the front as her legs are weedier than mine thankfully .

 

[mattr]

I've done the same on a couple of my bikes. Have bought a double front mech for both as the triple is a bodge and doesn't work as well as it could (I wasn't happy anyway, others might live with it). It was also quite easy to lose the chain out board when hammering through rocky stuff.
Moving the mech far enough down had it clipping the chainstay and shifting was less than ideal.

Bit of a no brainer for the 20 quid it cost me.

Also chain line isn't ideal on a converted triple, so my race bike got a proper double crank too. (No bash guard)
The training bike has stays about a metre long, so it uses a double/bash. And the chain line I live with.