Been quite a few times, both climbing and mountain biking. Selva Val Gardena is a pretty safe bet – couple of decent bike shops, tourist info have guidebook/maps of bike routes, and some of the lifts take bikes. Goes without saying that there’s often a fair old chunk of riding uphill on the XC/trail routes. Trail access can be an issue in the Dolomites (lots of German and Austrian ramblers y’see). It’s much better than it was, but definitely best to stick to set routes, or better still, hire a local guide through the tourist office – they know all the best bits of cheeky singletrack trails.
If you do go to the Selva or ‘Sella’ mountain area, I can strongly recommend hiring a guide and doing the ‘Sella Ronda’. There are different variations of the route, but all involve riding a massive circuit around the Sella Massif. I did the ‘gravity enduro’ option (on my regular old trail bike) and it was a stunning full day out – about 950m pedalling uphill, 7 gondola/chairlifts and 4500m descending! I think it was 70 euro for the guide, but that included all the lift tickets that, if bought without guide discount, would have been about 58 euro!
We’ve never camped in the valley, but sure there are sites (maybe more nearer a town called Ortisei, which is just down the valley from Selva).
HTH
