Came to service my spare bike today and as I lifted the wheel out of the frame, the freehub fell off. It’s a 135qr hub and axle has sheared completely in the location of the pawls. It’s a superstar switch ultra hub. Is is worth repairing- are replacement axles available? Not sure why it’s sheared, bearings seem fine.

Even if replacement axles aren’t available just buy a new hub and gut it for spares. In fact that’s probably a better idea anyway, gets your spare bearings, freehub etc. No point throwing the wheel away for that.

http://www.superstarcomponents.com/en/switch-rear-adaptor.htm

axle available here.

I’ve seen axles break on various hubs from hope to own brand, it may have been a dodgy axle but fortunately they are not too expensive to replace.

I had exactly the same thing happen on a Switch Ultra. Replacement axles are available. I’m not 100% sure about the durability of the superstar axles, though, but these are the hubs I have got so slapped a replacement in.