Originally Posted by GeezyRider
As you can see, there is still plenty of room for more rubber. If I had a burning desire, I could probably easily fit 20x1.95 tires on the bike.
That looks a little iffy, to me. A larger tire probably needs twice as much extra vertical space as needed for each side. If the frameset accommodated V-brakes, there'd probably already be enough room for 50mm tires.