Interested in upgrading your TruTrainer Travel cycling rollers to our Classic model to add inertia and resistance to your cycling workouts? Our Flywheel Load roller comes with everything you need to get a real world ride sensation unparalleled by other stationary cycling trainers. The upgrade kit consists of a fully assembled rear roller with integral flywheel/viscous load device with mounting nuts, a flywheel belt guard and mounting screws along with a flywheel drive belt. TruTrainer’s design features a tubular steel flywheel encased within an aluminum roller tube. The flywheel spins 4 times faster than the roller via the geared belt drive. What does this mean to you? Simple, you get a real world ride sensation that includes momentum and aerodynamic drag force simulation; and converting your Traveler Rollers is a snap and can be accomplished in 15 minutes with a 6 mm Allen wrench.