Trainers & Mountain Bikes Can I use a trainer with a mountain bike? 

I want to the same bike off road at weekends so I don't really want to change the setup of the bike.
You can use a trainer on a mountain bike, but a big issue that you will run into if you don't want to change set-up between the trainer and your rides on the weekend is that running knobbly tyres on a trainer is just plain noisy. If you are determined to run the same tyre on the trainer as off-road, I'd recommend looking into the tyres that have a raised, slick low rolling resistance portion in the middle, with knobs on the sides to help with cornering.