If you have 5 or 6 hours to spare, this is quite a nice route. I would start it from either Two Dales or Bakewell personally, if I wasn’t starting from the train.
http://www.bikehike.co.uk/mapview.php?lnk=http://www.cs.nott.ac.uk/~jqm/Long_Matlock.gpx
Lots of good trails on that route too, except for the obvious Monsal Trail boring railway track bit. Bakewell-> Chatsworth -> Baslow Edge -> Great Longstone -> Bakewell is a really nice loop. The Chee Dale, Monsal Head bit is not so much about technical challenge – more of a scenery and nice big hills section.
Oh and I may have got the wrong turning marked in Little Longstone for the Monsal Trail – just take the path signposted Monsal Trail, I think it might be the next one down the road.