When our MiG-21 was shipped from Bulgaria, the tires and wheels were removed from the gear legs (which are part of the wings) and tucked into the wheel wells. We finally fished them out and man are they heavy! Of course, they have to be... many, many plys to take the abuse of landing at over 150KIAS. The MiG-21UM lands just a tad slower than older models (it is, after all, a trainer) but you still only get about 22 landings to a set of tires, and that's if your luck holds out.
Here Phil is seen commenting on the similarity between a MiG-21 tire and a 1953 Dodge truck tire.