Did the swap and a few experiments today in a bid to answer some questions...
Sizes.....
xtr m900 jockey wheels are 8.2mm thick including plates to each side and take a 5x 12.5mm bolt
Xt m735 ( my only comparison) use the same centeron top jockey wheel system, but they are not the same. This version of xt are 10.2mm thick and use a 5x 15.7mm bolt.
You can swap the jockey wheels and the bolt over, but the float amount is different. Xt is 1.5mm.... xtr 1mm. In practice this did not shift as well and widens the cage towards the wheel. I doubt this made and real difference, but obviously its something to be aware of. I assume the xt float is more as it was made to run on wider spaced 7 speed systems.
The roller boy jockey wheels need to be fitted with the " type a" narrowest spacers supplied. This brings them to 8.2mm.
These have very limited float, but this is countered by the top jockey teeth being cut away on the leading edge, so the chain moves on the wheel.....rather than the jockey moving with the chain.
These are also directional.....note the arrows on the wheels or this will not work.
Shifting worked well straight out the box, and after a very slight cable tweek, solved a few of my niggles, probably being caused by a worn top jockey.
Photos. Roller boys ( note cut away teeth on top A jockey)......xt jockeys in xtr mech (too wide and too much float)......roller boys in xtr mech.
Sizes.....
xtr m900 jockey wheels are 8.2mm thick including plates to each side and take a 5x 12.5mm bolt
Xt m735 ( my only comparison) use the same centeron top jockey wheel system, but they are not the same. This version of xt are 10.2mm thick and use a 5x 15.7mm bolt.
You can swap the jockey wheels and the bolt over, but the float amount is different. Xt is 1.5mm.... xtr 1mm. In practice this did not shift as well and widens the cage towards the wheel. I doubt this made and real difference, but obviously its something to be aware of. I assume the xt float is more as it was made to run on wider spaced 7 speed systems.
The roller boy jockey wheels need to be fitted with the " type a" narrowest spacers supplied. This brings them to 8.2mm.
These have very limited float, but this is countered by the top jockey teeth being cut away on the leading edge, so the chain moves on the wheel.....rather than the jockey moving with the chain.
These are also directional.....note the arrows on the wheels or this will not work.
Shifting worked well straight out the box, and after a very slight cable tweek, solved a few of my niggles, probably being caused by a worn top jockey.
Photos. Roller boys ( note cut away teeth on top A jockey)......xt jockeys in xtr mech (too wide and too much float)......roller boys in xtr mech.
