Upgrading my lads 7 speed MTB, can I used a 10speed XT RD

[mattrixdesign2]

Different question/different bike to the one I have just posted.

My other lad has a Carrera MTB with modern shimano stuff, but only 7 Sp.

I have a spare XT (10sp) mech. Can I simply swap the mechs out? i.e. can a 7sp shifter work the XT mech on a 7sp cassette?

 

[hamster]

In short no, the cable pull is different on 10 speed MTB. Any 7/8/9 speed will work fine though.

 

[mattrixdesign2]

OK, thanks

 

[frank.youngman]

Re:

Surely poor advice.If I read the original post correctly the question is whether a 7 speed shifter will work a later rear mech.

The answer is yes,the mech itself is not indexed,it is the shifter which determines the distance the rear mech moves and preserves the indexing.

I used to routinely use 9 speed XTR rear mechs with 7 speed XT shifters.

 

[mattrixdesign2]

Re:

That is kind of what I was hoping. Its a low end shimano 7sp setup, I was going to just chuck in a spare xt mech. In the near future thinking of adding a 8-9 casette and new shifter. I don't think 10sp will fit.

 

[RickTheUncivil]

If shifter and cassette are both 7 speed, the mech will work like a 7 speed. I have mega 9 mech working 8 speed shifters and cassette, I have an old xt 8 speed mech working with 6 gears on my boys bike no problem.

 

[Sundayjumper]

Re: Re:

If I read the original post correctly the question is whether a 7 speed shifter will work a later rear mech.

The question is whether it will work with a 10sp mech.

The answer is yes...

The answer is no.

...the mech itself is not indexed,it is the shifter which determines the distance the rear mech moves and preserves the indexing.

True, sort of. The shifter is indexed and pulls a certain amount of cable per click. The geometry of the rear mech determines how far it moves for a given amount of cable pull. They need to be compatible. When they moved to 10sp, Shimano changed things.

I used to routinely use 9 speed XTR rear mechs with 7 speed XT shifters.

But you've never used a 10sp mech. Which was the question.

As hamster has already said, a 10sp mech will not work with 7/8/9 sp shifters.

 

[mattrixdesign2]

Re:

Lol. Thanks

 

[02gf74]

If shifter is index type, it will not work due to 10 spd mech needing mire cable pulled.

From what ive read, the amount is 2x, so a 7 spd thumb shifter will work with about 5 gears before it runs out of cable, never used thumb shifter but if they are like down tube shifters, the limit is set by the rear mech so it may work for all 7 gears.