Meggamouse has a jelly used in tyres for cherry pickers as their tyres need to be puncture proof. The jelly can be removed and fitted to other tyres. The ones on Meggamouse were on Velocirippa and are nearly 10 years old now, the hubs have been replaced many times but the tyres have all sorts of holes and still behave like a fully pumped up air tyre.

Downside; they are 3kg each, the jelly is injected as a liquid and baked for 24hours so has to be done professionally and is not cheap. 10 years from a set of tyres is pretty good value for money though in my book..........