After 250 km I had a flat tyre, no off-road and speed at maximum 45 km/h. It'very difficult to get a inner tube of the same size, only with unknown brand. Yesterday I changed it and today way already flat again. How is it possible that nobody has stressed the low quality of inner tube of these expensive toys? The inner tube of a monowheel should be developed for a double load (only one wheel..) but nobody seems to care about that even if these toys go at almost 100km/h. knows someone about a brand that produce a compatible inner tube?