Dave the Smeghead
Über Member
The tyre will be there for resistance. Would a running parachute do the same job? Something like this: -
http://www.amazon.co.uk/gp/product/B009OH7G4I
The tyre does so much more. Tie a rope round it and run with it for added resistance, flip it end over end on the ground for squats, back and arms, jumping in and out of the centre with "high knees", pull it with the rope from a seated position for arms and back etc.