Hey CC!

Sorry to be a bit late on the trigger, I'm traveling across the East right now, currently in Halifax, and have limited access to computers... (Not unpleasant!)

You indeed can mountain bike in Whistler, there are all sorts of trails that I know of, although I ain't no mountain biker.

Another option, especially if time is limited, is to stick to the North Shore. I believe there are interesting trails all over North Vancouver, and Deep Cove is known as the mecca of mountain biking. There are all sorts of trails there too. My theory would be that there would be a broader variety of difficult trails than easy ones there, but I could be mistaken.

I agree that you should check the other forum...