I've been given a basic full suspension mountain bike that I'd like to strip down and convert to single speed. I initially didn't think this would be possible without using a chain tensioner as it has vertical rear dropouts, and the rear suspension means that the bottom bracket to rear cluster dimension varies with the suspension travel. I've had an idea though. If i set it up with a single sprocket and chainring and a chain of approximately the right length could i fine tune the chain tension by removing the rear shock and replacing it with a custom length solid bar? (or possibly an adjustable one, but that might be tricky to make strong enough) I'd lose the rear suspension, which i don't want anyway, but would the rear of the bike be up to coping with undamped bumps through the rear wheel? I intend sticking to roads by the way.