There are various Rock Razors, including a sub 700g ‘Snakeskin’ version but the Super Gravity uses the latest evolution of Schwalbe’s four-ply sidewall, two-ply under tread Gravity carcass.
This keeps the tread mobile for moulding to the trail but the tyre very stable at low pressures to the point where it feels like a rear suspension upgrade. Once you’ve got the thick sidewalls into place it seals easily and the sense of trail connection is outstanding for such a sturdy tyre.
At under a kilo it’s noticeably lighter and more agile in feel than most tyres in its category. The ranks of multiple small split topped knobs are ramped for even easier rolling and it adds instant and obvious pace. You can put a surprising amount of brake or chain torque through them without slipping though.
The transition onto the big softer compound side knobs is seamless too, so grip increases just when you need it for corner carving. The only downside is potential tread tearing or delamination if you start skidding and scuffing too much, so ride smooth and smart if you want a reasonable return on an expensive investment.