Rear mech max sprocket ?

[nickfrog]

Hi,

My M950 XTR rear mech has an official "max sprocket size" of 32t.

Has anyone managed to fit a bigger cassette (34t) on a mech with such limitation ?

Thanks.

Nick

 

[scant]

it'll work, you might need to dial in the B tension screw depending on the shape of your dropouts mech hanger.

 

[littleblackflash]

Why,

Hill's aren't that steep near Worthing. Have you considered a smaller chainring?

 

[nickfrog]

Sorry, I should have explained.

I am converting to single chain ring which will be a 29t as I am sacrifying the top end (which I only use on the road, ie never) to the benefit of the low end where I will only lose half a gear compared to my current triple M950 set-up.
The question is, am I going 10 speed with a 11-36 which means changing rear mech too or shall I compromise with a 34t / 9 speed and keep the rear mech?

Hills here on the South Downs are very short but can be brutal and I am fat and old.

 

[littleblackflash]

I'll try the 11-32 first and if you can't get up the hill, then try an 11-34.

BTW, I'm also in the South Downs hills and old, overweight and lazy cycling goupe

 

[nickfrog]

I just got the ring today amusingly so I'll fit it as it is keeping the 11-32 as you say and then maybe go up to 34.
The scary bit is when you look at the figures:
Currently 32t x 24t = 1,56M
32t x 29t = 1.88M
34t x 29t = 1.77M
36t x 29t = 1.67M

 

[cyfa2809]

Currently 32t x 24t = 1,56M
32t x 29t = 1.88M
34t x 29t = 1.77M
36t x 29t = 1.67M

what is this? ive seen perry talk about it but have no eyed deer what the hell is it? (x) spins of crank = distance moved (in that ratio)?

 

[nickfrog]

Yes, that's what it is, M is meters, for each revolution of the cranks, it's the distance covered.

 

[Harryburgundy]

Meters gained...the late great Sheldon will explain

 

[one-eyed_jim]

Pedant here says:

little m for metres.

Meters gained...the late great Sheldon will explain

It's normally referred to as development. Sheldon uses "gain ratio" to mean the reciprocal of mechanical advantage.

My M950 XTR rear mech has an official "max sprocket size" of 32t.

Has anyone managed to fit a bigger cassette (34t) on a mech with such limitation?

No problem.

Incidentally, Shimano now make a 9-speed 12-36 cassette. I've been thinking about using one to set up a low-geared 2x9 - probably something like 40 28 at the front.