Originally Posted by dabac

If extreme durability is what you're after you might also want to consider using even numbers of teeth on both sprocket and chainwheel. If you also keep track of which teeth on both sprocket and ring that ends up between outer or inner plate(one tooth on each end is enough) you can keep the whole drivetrain going in synch, which is supposed to give you a bit of extra wear out of your parts before replacement will be required.