Probably all the best riding is around Truro, Penzance way so you'll be close to some of the best stuff in cornwall. I live in north cornwall (Wadebridge area), north cornwall is alright, but not as many spots as south cornwall though. Hustyns though is good for AM sort of riding, plus cyclist have right of way over walkers and horse riders so there's plenty of trails to be found, better in the winter though as the brambles are a nightmere.