3M cart band tension

I just thought of a really simple way to tell if the band in your 3M cart is shot if you don't happen to have a tension meter handy. Take off the cover of a known good cart, set it on a table with the capstan roller facing away from you and pull the band at the edge closest to you with your index finger. The cart will move towards you on the table after about one row of dots (for example) on the baseplate of belt deflection. Good belts will provide quite a bit of tension by the time you reach the edge of the cart. Obviously, the exact values vary with the friction on the surface you're using, but you get the idea. Bad belts have significantly less tension and require a lot more deflection to produce enough force to overcome the friction of the table.