Bontrager's Race Lite Stem is a reliable race-ready tiller worthy of the finest road and mountain machines. Thanks to its one-piece, cold-forged 6061-T6 aluminum construction, it's strong, light and stiff. The CNC-machined 4-bolt faceplate is ultra tough and evenly distributes clamping forces your bars. And, the angled, opposing-bolt steerer clamp is safe, secure and compatible with carbon steerers.
Stem length is measured along the side of the stem from the center of the steerer to the center of the handlebar clamp (see diagram). Keep in mind that as a stem provides more rise, its effective length decreases. In the example above, if the +17-degree stem measures 135 mm, it actually extends 108 mm parallel to the ground.