Bike-maker Trek has something new this holiday season, two models without chains.
It's the first time the chain-less technology is being used in mass-produced bikes.
Instead of the dirty, noisy chains, a silent carbon-fiber belt connects the pedals to the rear wheel.
Trek officials say the belts are not only grease- and rust-free, they also last longer than the old school chains.
The chain-free bikes start at about $930.
