|9 speed freewheels?????||oncetcr1|
Aug 9, 2002 11:46 PM
|I live in australia and i have a pair of zipp 440 rims, the rear had a screw in 7 speed sach cluster on it and im wondering if u can get 9 speed version or a screw on cassette body, cus my local bike store reckons they dont exsist|
|I reckon your local bike store is right. Here's why:||Spoke Wrench|
Aug 10, 2002 11:20 AM
|A hub that uses a spin-on freewheel has the drive side axle bearing inboard of the freewheel, under the hub flange. The axle from that point outward to the frame dropout is unsupported. On a cassette hub, the drive side axle bearing is located farther out, actually within the cassette freehub body.
The farther inward you move the bearing, the more apt the axle is to bend. I think that hubs with seven speed spin-on freewheels are on the marginal side for axle bending frequency. I wouldn't want to go any farther.