Choosing New Rims/Hubs & Assessing Size I have a 10 year old Trek 7300 FX hybrid which came with Matrix 750 double walled rims. "559 x 19" is marked on the sticker of these rims. The tyres fitted are 700 x 38C (622) - I'm assuming (should I be?) that the rim/tyre combination give me a 700c wheel?

The problem I have is that the freehub on the rear has gone (there's a crack on the inner cone section covering the bearings) and so it's not freewheeling without locking the chain up, and I'm thinking about a new hub and spokes versus a set of new wheels. Looking at the hassle versus cost savings, it seems that Amazon will provide a decent set of wheels spoked, hubbed and tyred for around £60 whereas a wheel rebuild might save me about £10 to £20 on that amount.

Any ideas?
Freehubs can be removed from the hub and replaced; it involves removing the axle from the hub and then loosening a fixing bolt with a 12mm allen key.
Visit your local bike shop and ask if they have any thrashed rear cassette wheels; if they're cool they'll give it to you free or next to free.  Pull the freehubs and hope to find something compatible; there are several different spline patterns.