ON RUNNING CLOUDBOOM
£170 The carbon midsole revolution continues with the Cloudbooms
Carbon fibre’s impact on running continues apace with On’s new Cloudbooms, which feature their traditional Speedboard infused with 15% carbon. Why not 100%? On’s 100% prototype shattered into pieces within the first kilometre. That’s why they settled on that 15%, striking a proficient balance between stiffness – so maximising energy transfer – and run-gait flexibility.
The Speedboard is the carbon filling in another first for On – a double set of their lugged CloudTecs. This dual offering is supplemented with their Helion foam, which is damn comfortable. And impressive. As are the speed credentials. Over runs ranging from 5km to 15km, they felt fast. Very fast. In fact, they raised a smile few shoes do. The carbon hit helped, as did the mild curving of the Speedboard that allows for a rocker motion. On says it’ll work up to a marathon. For biomechanicallysound athletes, we’d agree. Everyone else should set their limits at 21km.
Weight is a pretty good 248g (for UK10.5), which is partly down to the incredibly thin mesh upper. In all honesty, it’s so thin we question its durability and would advise keeping those toenails trimmed. Questions are also raised about the durability of the lugs as a couple tufted up during the test period, yet that was down to sharp stones wedging between the lugs when we diverted off-road. So keep these for road use only. All in all, these are cracking shoes, if at a high cost.