Kent T-29 Men's Mountain Bike, 29-Inch A lightweight 6061 heat treated aluminum frame provides an excellent foundation Shimano RS25 Shifters and TZ31 Derailleurs ensure a precise and crisp drivetrain Lightweight alloy 29-Inch rims provide lower rotational weight compared to steel rims making the bike feel agile and easier to handle 29 x 2.1 inch all terrain knobby tires provide great grip on any surface The 170mm crank set with 28, 38, 48 tooth rings is made from steel for durability and strength