Attach the ENVE Carbon Clip-On TT Bars to your existing road bike for the aerodynamic efficiency desired for triathlons and ultra-endurance events. It's a solid choice if you're just starting in triathlons, as you won't have to empty your bank account on a time trial superbike. The Carbon Clip-On TT Bars (and pad carriers) employ uni-directional carbon for exceptional stiffness and strength, as well as lightweight riding efficiency. They attach to standard 31. 8-millimeter bars found on your road bike, giving you the option to cut them in with either a J or S-bend shape.