Schwalbe built these tyres to offer almost as much grip as the Racing Ralph but, thanks to that close-packed tread in the centre, to roll faster than the ridiculously fast Furious Fred. Schwalbe’s Rock Razor, while crazy quick, thanks to its Prodigy-haircut design that’s bald in the middle and spiky on the sides, is rear-only on all but the driest hardpack. The Thunder Burt is more versatile.
At 425g and with minimal tread it’s eager to accelerate. On hardpacked trails the almost complete lack of trail buzz sees it fly along. The cost is thin sidewalls, so with lower pressures the carcass rolls on the rim and rock/pinch damage is a risk. We struggled to get our early production samples to seal tubeless, however it’s also offered in a SnakeSkin version, which adds a bit of extra sturdiness and makes it easier to seal.
They’re too flimsy for spirited trail riding, but put the Thunder Burt in the context of racing tyres and it makes a lot of sense, especially on the rear with a decent pressure to protect it.