With the old racing ralph tread this schwalbe rapid rob active kevlar guard wired mountain bike tyre is an attractive option for beginners the foundation of all active line yres is a high quality 50 epi carcass coarsely woven 20 or 24 epi carcasses can no longer be found in schwalbes range the much more densely woven 50 epi carcass is far more puncture resistant and robust at the same time the fabric needs less rubber coating and thus has a reduced weight naturally every active line tyre h