Long or Short Rear Mech?

DonLykeB

Hey Everyone.

Completely inexperienced when it comes to gear sizes and the such.

Pretty much I need to buy a new rear mech, and I wanna buy this one http://www.chainreactioncycles.com/mobi ... 7C258685UK However I really don't know which size to pick, I have a 10 speed cassette. 10 Speed chain and a two speed crank HOWEVER I only ever use the larger gear on it.

The sizes for the mech are as follows:
Large - 47T
Medium - 39Y

I have a Boardman Mountain Comp 2016. If anyone could help me out here I'd be very grateful.

DonLykeB

DonLykeB wrote:

Hey Everyone.

Completely inexperienced when it comes to gear sizes and the such.

Pretty much I need to buy a new rear mech, and I wanna buy this one http://www.chainreactioncycles.com/mobi ... 7C258685UK However I really don't know which size to pick, I have a 10 speed cassette. 10 Speed chain and a two speed crank HOWEVER I only ever use the larger gear on it.

The sizes for the mech are as follows:
Large - 47T
Medium - 39T

I have a Boardman Mountain Comp 2016. If anyone could help me out here I'd be very grateful.

cooldad

(Number teeth big ring minus number teeth small ring)plus( Number teeth big cog minus number teeth small cog)= capacity.

If it's 39 or less, medium cage will be fine. 40 upwards get a long cage.

Chances are with a double ring a medium will be fine. Unless you have a crazy huge cassette.

DonLykeB

cooldad wrote:

(Number teeth big ring minus number teeth small ring)plus( Number teeth big cog minus number teeth small cog)= capacity.

If it's 39 or less, medium cage will be fine. 40 upwards get a long cage.

Chances are with a double ring a medium will be fine. Unless you have a crazy huge cassette.

Counted 38/24 on the Crank and 36/11 on the Cassette which brings me to 39. So I guess medium it is, thanks alot!