Large diameter, 1-1/8" (28.6mm), double-tubed handlebar that combines great strength, excellent resilience and a virtual guarantee against fatigue failure. Consists of two aluminum alloy tubes, one within the other. Outer tube is 7010-T73, which has extreme resistance to mechanical damage. 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.