Mavic prides itself on the quality of its R&D. Not content to just launch the new tubeless ready Cosmic Ultimate UST all-carbon wheelset, it’s also shared extensive research on why you need tubeless. Its recommendations on tyre pressures across different terrains are embedded in the MyMavic app.
First off, Mavic measured rolling resistance at different pressures (measured in Bar across the bottom of the graph: 4 Bar is 58psi, 6 Bar is 87psi and 8 Bar is 116psi), indicating that a UST tubeless set-up (the blue line) rolls better regardless of tyre pressure, but particularly at lower pressure.
Next up, rim width. Testing 23, 25 and 28mm tyres on rims that were 17mm, 19mm and 21mm wide shows that there’s little difference in how well the tyres roll between rim width (although other research suggests that there may be aero benefits from the smoother rim-to-tyre transition with a wider rim).
Then Mavic investigated the effect of road surface on rolling resistance at different pressures. This is interesting: whereas the higher the pressure, the lower the rolling resistance in a lab simulation on a smooth drum, on a real road surface, there’s a tyre pressure sweet spot at which rolling resistance is minimised. Pump up your tyre above this pressure and you start to add rolling resistance, particularly on a rough surface. Tyre compounds are typically tested for rolling resistance during development on a machine with a smooth drum.
All this is plugged into the MyMavic app algorithm, which will spit out a recommended tyre pressure front and rear, dependent on your weight, your bike’s weight, your tyre and rim widths, where you ride and how comfortable you want to be, as well as whether it’s raining or not.
We reckon that the Mavic pressure recommendations are a bit higher than we’d normally ride. But then we do have especially bumpy road surfaces here in the UK.