The Michelin X11 Trials tyre has been the top choice for trials riders world over for years. The tread blocks are made from a very gummy flexible rubber. This flattens out the tyre to provide maximum tread contact patch with the ground surface be it rocky or hard packed clay. Many riders use the 400-18 tyre on the rear for dirt track racing and even general trail riding because they work and last very well. The X Light is best left for Trials bikes.