MrSparkles

Happy Thanksgiving to all.
Can current Shimano 105 brifters (ST-5700) operate current Shimano MTB rear derailers (I would like 34-36 teeth capability)? Is it likely my LBS can set this up?

Can current Shimano 105 brifters (10speed) operate 9 speed Shimano MTB rear derailers? Is it likely my LBS can set this up?

Thanks!

cyclist2000

I thought that you would use a 9 speed mtb derailluer with the 10 speed 105 shifters. I am using a the ST-5603 with a 9 speed mtb derailuer on my touring bike.

onespeedbiker

What am I missing here?

Anyway, to the OP, as long as the mtb derailleur is the standard high normal; this is a common pairing for touring and tandems.

shelbyfv

9 speed mtn bike rd will work, 10 speed mtn bike rd will not.

MrSparkles

To make my convoluted questions more succinct; my current drivetrian is 2012 Shimano 105 including brifters, I would like 34-36 tooth capability in the rear which means I must install a MTB RD. Will my 10 speed 105 brifters work with 9 speed MTB RD? I like the Shimano LX T661 that Rivendell sells.

onespeedbiker

Yes, the LX T661 mtb derailleur will work with your road 105 brifters.

HillRider

+1. However you will have to continue to use a 10-speed cassette and chain unless you install the proper J-tek Shiftmate to allow 10-speed brifters to operate with a 9-speed cassette.

onespeedbiker

Why would the OP want to revert to 9 speeds? He has 10 speed brifters and a 10- speed cassette already and will be buying a new 10 speed mtb cassette; the only question was can the OP use a 9 speed derailleur to shift with a 10 speed cassette and the answer is yes. The problem is Shimano 10 speed derailleurs are the new Dyna-Sys, which are not compatible with the OP's 10 speed brifters, but the RP can use a Shimano 9 speed derailleur in place of the Dyan-Sys 10 speed derailleur. And the answer we both agree on is YES!

HillRider

I fully understand and agree with what you are saying. The only reason I referenced a 9-speed cassette at all is that they are easier to find and more available in the wide range the OP wants to use. I realize shimano and SRAM sell 10-speed cassettes with 32 or larger cogs but they are pretty new on the market.

WingSuit

Sent you a message, Mr Sparkles

eofelis 

Yes, it will work. My Specialized Ruby road bike has 10sp Ultegra 6600 sti shifters and a 9sp XT Shadow rd on a 10sp 11-36 cassette. It works perfectly. We have a few hills here in Colorado.
My bf set this up. He has also set up some friend's bikes like this (Ult & 105 10sp sti's).

cycle_maven

I use 10-speed brifters (microshift and shimano ultegra) successfully with 9-speed MTB derailleurs (Deore LX) *and* 9-speed cassettes. To do this, you don't need a Jtek shiftmate- all you need to do is use the "alternate cable routing" (google it) to the derailleur and set the limit screws correctly.