There are 2 basic types of gear clusters for rear wheels. Casette and freewheel. Freewheel threads onto a seciton of the hub, whereas casette type hub has a splines and the casette slides onto the sprines and is retained by a locking nut.

Casette hubs support the axle farther out by having a bearing placed outboard, under the end of the splines, and freewheels support the axle right at the hub. Much easier to bend or break a freewheel axle vs a casette.

do a search, there is a ton of information. Casette is better, but I do not know if you can get a 127mm rear spaced hub or not.


Tom