I live in Colorado and have a torn meniscus. Its been about 4 weeks since I’ve torn it and the pain is subsiding. I went for a light 15k bike ride yesterday on my road bike. The route I took had hills and also had some flat parts. I was pretty skeptical about riding with a torn meniscus, but it didn’t turn out too bad. The only part that hurt is when I stood up to pedal on those big hills. Also sprinting took a pretty good amount of pain along with the improper gear shifts. Overall road biking with a torn meniscus isn’t that bad. It doesn’t hurt at all unless you do the things hat I mentioned. Mountain biking on the other hand I would stay away from, especially if your jumping, standing up to pedal or standing on rough downhills. I know you hate to hear it, but in this case road biking is by far the best if you have any hope in staying fit before your surgery.