Chain or shaft drive in Sahara?
 

Any advice if spare chain and sprockets are needed, for drive through Sahara on Atlantic route to Ghana and back to Europe?
Considering all sand, gravel, stones etc...

Or is shaft drive the no 1 choice?
-Leaves only a few bike choices...

a chain should do you for 15-20,000km as long as you let it run dry. putting grease on it attracts dust which grinds the rollers and sprockets. if you're doing a fast day on tarmac, pour a little engine oil the rollers, but don't use grease. I did 5,000km on an XR400 last winter and barely adjusted the chain.
Richard