With the magnetic or fluid Trainer, the rare wheel rotates on a small 1’’ solid steel roller. If one ride with the original tire of the bike, it gets bald and then worn down due to excessive heat produced by the small steel hub rotating at high RPM and the tire positioned at one point only. So Trainer tire is a must for such bike trainers. However, in the case of   ‘Ashwa Pro Traveller’, a Trainer tire is not required. This is because the rare wheel is not stuck in one position. It actually swings on two aluminum drums of 4’’ diameter which does not generate any heat at whatever speed or rpm you ride.