With a new 320tpi cotton casing, updated tread pattern with aero dimples, and a race dual compound rubber, the new Bontrager Aeolus RSL takes the mantle as their top (and fastest) road bike tire.
The new tire replaces their R3 TLR and takes a multi-pronged approach to making you faster. The cotton casing is much softer, which helps it deform to the ground more easily for a smoother ride with less rolling resistance.
Underneath the tread cap is a puncture protection belt that, combined with a tubeless setup, helps keep you rolling. A protective layer around the bead keeps the rim from wearing down the cotton and also adds a bit of pinch flat protection.
It also gets a new dual compound rubber, putting a harder rubber in the center so it rolls faster and softer, grippier rubber on the sides for cornering. They say this saves 3.7watts in rolling resistance. But that’s not all…
While Bontrager didn’t dive very deep on explaining the aerodynamic benefits, my guess is it’s the strips and dimples that help trip the air and keep it attached for reduced turbulence. It’s a very different design than the new Continental Aero 111, but they have some numbers to back it up.
What’s noteworthy about this graph is that there are some savings even on the lower end of the speed spectrum (albiet still at a pace most of us aren’t holding solo), and also that the improvements are on a wider 28mm Aeolus tire versus a narrower 25mm R3.
It’s compatible with hooked and hookless rims, but note that the maximum tire pressure varies based on both tire width and rim type.
It comes in 26mm (265g), 28mm (285g), 30mm and 32mm widths. (NOTE: Weights weren’t provided for all sizes yet and based on pre-production models. I have a set in for testing and will provide actual weights in a future review.)
