The revolutionary Twinwall handlebar is an oversized diameter 1-1/8" (28.6 mm) handlebar which utilizes two tubes, one within the other, borrowing principles from aircraft design to give the best combination of lightness, strength and safety. Since their introduction in 1998, the Twinwall has been the handlebar of choice for more professional race teams and has helped more riders win championships than any other handlebar in the world. The following features are integral to the Renthal Twinwall handlebars: Twinwall construction - consists of two aluminum alloy tubes one within the other. Outer tube is 7010 T73 aluminum, which has extreme resistance to mechanical damage and is anodized to prevent corrosion. Inner tube is ultra high strength 7010 T6 aluminum and is hard anodized to resist wear from twist grip and controls. Rubber seals cover the join to keep out water and cleaning fluids. Laser-etched positioning grid. Renthals pioneered bonded lightweight single bolt clamping system for the crossbrace, greatly increases strength whilst still allowing flex. Knurling - grip end only - increases bonding between bar and grip. No knurling in clamp area, this could cause stress on the riser and lead to fatigue failure. A specially developed injection-molded crossbar pad is fitted with every handlebar. Note: Renthal Twinwall handlebars require the use of oversized 1-1/8" handlebar clamps. Renthal Twinwalls are used by more factory teams than any other handlebar, including: Honda Red Bull Racing, Monster Energy Kawasaki, Pro-Circuit Kawasaki, Rockstar Suzuki Canidae, TLD Lucas Oils Honda, Team Honda Martin Racing, Team Kawasaki Europe, Team Suzuki Europe, Factory KTM Europe, HRC Honda Japan, KHI Kawasaki Japan and Suzuki Japan. Renthal. We build championships.