Hi Martin
CW front and rear wheels are interchangeable. Hubs being the same but totally different from other 2.3/4hp hubs, and both having a dummy belt rim for the brake mechanisms. The sprocket is dished and retained by a notched threaded locking rim secured by a "C" spanner. The sprocket has tapered splines in its centre which engage with the matching tapered splines on the offside of the hubs. There are 100 splines on this locating arrangement. The sprocket itself is very heavily fretted like a cobweb and being dished and having this splined center is a very difficult and expensive item to make from scratch. I have always recommended that where an original exists it should be re-toothed when the sprocket teeth have become worn. Because of the fretting the amount of metal available on the outside to turn off and weld a new ring of teeth is very small and the best solution is to reduce the overall gearing slightly by adding one tooth to the gear which has the effect of making it slightly larger and giving a bit more metal to make a good weld. Chris.
