The large flywheel housed in the body of the Hammer allows it to simulate grades up to a leg-busted 20%. CycleOps Hammer direct-drive smart trainer. © Z. Schuster / Cyclocross Magazine

The large flywheel housed in the body of the Hammer allows it to simulate grades up to a leg-busted 20%. CycleOps Hammer direct-drive smart trainer. © Z. Schuster / Cyclocross Magazineundefined