The 51 SPEEDSHOP Mono-Riser Aerobar System eschews the typical twin tower stack of most aero bars in favor of a single, adjustable spacer stack. The design’s wide base provides stability while also simplifying setup…just two main bolts hold the armpads and extensions assembly in place, and it’s adjustable in almost every way to get the perfect fit and position.
The main pillar uses 5mm and larger spacers, allowing you up to 65mm of stack, adjustable in 5mm increments. The extensions’ base can be angled within a 12º range to find the right tilt, and multiple elbow pad base plates allow for plenty of fore, aft and lateral positioning options.
Brake cables run internally through the bull horns and pop out the side of the stem for smooth lines running into the top tube, where many tri bikes place their entry ports. Claimed weight for the system is as low as 816g in the slammed position, but more spacer use will up that slightly.
The kit comes with everything you need for $899. All hardware is corrosion-resistant stainless steel, and the carbon base bar is stiff enough to resist torsional flex during out-of-the-saddle sprints. Its Kamm-Tail profile keeps it aerodynamic.