Planning 2x11 with 11-40 XT cassette rear.

[bernatv]

So the plan is:

105 11 speed hydraulic shifters.
XT 11 speed 11-40 cassette.

Which rear derailleur??

-Looking deep in internet I've found the Shiftmate 8 to use that with a Shimano XT 11 speed rear derailleur...
or:
-Found a hack to convert a Shimano 105 11 speed rear derailleur so it accepts a 11-40 cassette...

Should be 105 so, any other idea??

thanks and cheers!

[mattyNorm]

I'd say 105 so if this doesn't work you don't waste too much money, what chainrings are you planning on using?

[nickcube]

I'd try the hack with the xt mech and see if it works. The cage will play nice with the 11-40 cassette and it has a clutch

[the_marsbar]

Can't use MTB mechs with road shifters AFAIK...

[Marin]

Do you really need 11-40? I.e., do you need a 50-11 gear on a bike that has a 40 cog in the rear?

BTW, my long cage 6800 derailleur can shift an 11-36 without problems.

[basilic]

What 2 chainrings are you going to use? If you are going to live with the big jumps on that cassette, why not just a single 48 up front.
Or else, go electronic and use 50/46 (or similar) to split the difference between the cogs: 50-11, 46-11, 50-12, etc (like the oldtimers used to do)
You'd have to hack the sftware though.

[bernatv]

I'm doing it for a friend. Thanks for comments.
Chainrings probably 46-34.
No way on 1 chainring. He wants hydraulic brakes and 105, tight budget...

[dfischer1]

34x40 is an abnormally low gear and will have too much torque resulting in a front wheel hopping all over the place, or a back wheel consistently losing traction. An 11-32 cassette with 34/46 chainrings is more optimal.