Off to Cornwall, near St Austell for summer hols and could do with taking bike to keep the legs turning pre-SiTS. Is there any good riding to be had or am I best sticking some slicks on and doing some road miles?

Dunmere Woods nr Bodmin is good, Bissoe/Poldice Valley is brilliant and there are loads of other areas. Well worth bringing your MTB! It's great for road riding too though.

Cheers, I have found details of the Camel Trail. I assume this would be the best option for a family ride with trailer etc?

camel trail is a good family option, also worth looking at the bissoe to portreath trail,family friendly,a bit more interesting and a bike friendly cafe at bissoe and a pub at the other end, job done.

I've heard good things about Bissoe area too and there's some youtube vids of it. I was going to go there but I'm flying down now.

Bissoe is great – easy track for families, some pretty full on DHing, climbs and jumps plus mad drops for the nutters.

Camel Trail is fine but pretty "easy" and gets very busy. Best to go from Wadebridge towards Bodmin – much quieter.

Found this place helpfull

http://www.cornwallcyclehire.com/

If you're staying near St Austell you could ride out to the Luxulyan valley, and ride up through there. When you pop out the top you're near to the Eden project, and can grap a few road miles over towards Bodmin for a ride round Cardinham. Nothing amazing, but better than just spinning around the roads (which will be busy in the summer)