Downhill Mountain Biking
Three ski resorts offer lift-accessed biking in the Canadian Rockies. The best is probably Kicking Horse Resort, though Fernie Alpine Resort comes a close second. Panorama is a little smaller and tamer, though worth a stop if you're passing by.
But many of the best and most challenging trails are outside the resorts and of the home-made variety and accessed by locals who take turns by shuttling the trails using 4x4 pickups in groups.
This is a hard thing to set up for the visitor, but, if you can try Mount 7 near Golden (which can generally be driven using a normal 2-wheel-drive vehicle) and 3 Kings near Fernie which you'll need a 4x4 to access. The local info centres can give you direction to either.