Hollow Stem (31.8mm Bar Bore x 53mm)

Incompatible with carbon fiber steerer tube forks, these Box Two Center Clamp 1 Inch Stems are crafted from premium 6061-T6 aluminum. They boast an open skeletal design and single mid-bolt wedge mounting, making them one of the lightest 22.2mm bar bore mini stems available. A 40mm extension stem weighs only 132 grams/4.6 ounces. Featuring a single-bolt wedge clamp, they eliminate rear-facing pinch bolts that could injure the rider's knees. Available in 40mm or 45mm extensions, and in anodized red, blue, or black with laser-etched graphics and five hollow chromoly Allen bolts. Suitable for 22.2 handlebars, they require at least 30mm of exposed steerer tube for proper clamping force. Not compatible with carbon fiber steerer tube forks. Maximum recommended user weight is 99 pounds.

• MAXIMUM POWER DELIVERY: The Box One Oversized 31.8 x 1-1/8" Center Clamp BMX BMX Bike Stem features an enlarged interface and larger surface area to ensure optimal energy transfer from handlebars to wheels. This minimizes energy loss and increases stiffness, giving you faster acceleration and sharper handling during aggressive riding.
• PRECISION STEERING CONTROL: The Box One Oversized 31.8 x 1-1/8" Center Clamp bicycle stem, cold-forged from 6061-T6 aluminum, minimizes twisting and flex, maintaining a strong, stable connection between your handlebars and fork. The result is ultra-responsive steering, ideal for navigating technical trails, making quick maneuvers, or sprinting off the line.
• KNEE-FRIENDLY CLAMP DESIGN: Engineered with a dual mid-bolt wedge clamp system, the Box One Oversized bicycle stems move bolts away from your knees to prevent contact and injury. This design also reduces weight and offers a sleek, compact profile perfect for BMX racers who demand comfort and control.
• LIGHTWEIGHT AND DURABLE: Designed for strength without extra weight, the hollow 6061-T6 aluminum construction offers outstanding durability at just 244g (53mm) and 246g (60mm). With a 0°degree stem, 44mm stack height, and chromoly bolts, it's built for serious riders who need power and reliability.
• COMPATIBILITY AND SIZING: Box One Oversized Center Clamp bike handlebar stem is available in two sizes: 53mm and 60mm. The stem fits 31.8mm handlebars and 1-1/8" steerer tubes. It is fully compatible with Box One XL, X2, and X5 forks, as well as Box One Cro-mo and Alloy Triple Taper handlebars. Not compatible with carbon fiber steerer tube forks.