Schwalbe's Rock Razor
is an important tire. No doubt half of you will stop reading as soon as we mention that it was developed from enduro racing, but bear with me. One of the best things about the discipline, is that companies are pushed on to develop products that are really very good out in the real world, and not just up in the rareified air of World Cup racing. Here in Europe, top enduro racers have been running semi-slick rear tires, like the Maxxis Larsen for a number of years. The logic is that if you have long transfers to tackle on the saddle, a fast-rolling rear tire helps you save precious energy for when the clock starts. Yet, there was always a big sacrifice, because for technical terrain, you had no tread to help you when things got ugly. That lead some clever folk at Schwalbe rethink the semi-slick tire saying, "Why can't we at least have tread on the side?" The result is the Rock Razor.
Rock Razor semi-slick is one of the most innovative tires of recent years
• Purpose: All-mountain/trail/enduro/downhill (dependent on carcass)
• Sizes available: 26 and 27.5, 29-inch from summer 2014
• Carcass: 2.35-inch, Evolution-Snakeskin and Super Gravity
• Compounds available: Pacestar, Trailstar (intermediate)
• Tubeless ready: Evolution Snakeskin and Super Gravity carcasses
• Weight: 665g or 925g (26" / dependent on carcass)
• MSRP: $93.25 (Super Gravity - tested)Construction
We looked in depth at the construction of Schwalbe's new aggressive tires when we reviewed the Magic Mary
, so we won't go into depth about that here. The Rock Razor comes in roughly the same sizes and options as the Magic Mary. It is the tread pattern, though, that matters with the Rock Razor, that is where the big innovation is. It as a semi-slick design with DH side knobs. And they are big side knobs - a shade smaller than Magic Mary, but still so substantial that they would look more than at home on most full-blown DH race tires. The side blocks are lined up consistently - all the same size and the same space apart - which is vital for cornering when you dig the side of the tire into the ground. On the top, the small block pattern is square, also with consistent spacing, and while there may not be much tread, what is there behaves utterly predictably. Schwalbe adds a little moto influence to the crown tread, with every other row slightly raised to increase braking bite.
It is the combination of fast-rolling center blocks and a burly, aggressive edge pattern that makes the Rock Razor so good. Schwalbe offer it in three different casings to suit any style of riding.
We tested Schwalbe's 1,000g, Supergravity casing, with the Trailstar rubber compound, in both the 26 and 27.5-inch wheel sizes. Mounting the tires tubeless depended very much on the rim. With the DT Swiss EXC 1550 wheels, the Rock Razors needed a compressor to seat the beads. With the newer DT Swiss Spline ONE EX 1501 and Stans Flow EX wheels, they were a joy to work with, more or less seating with a floor pump.Out on the TrailClimbing:
Switching from a full knobby tire, like Schwalbe's Magic Mary to a semi-slick tread pattern is nothing short of a revelation for long road and fireroad drags. Even though the Super Gravity version of the Rock Razor weighs the same as a Magic Mary, it transforms how the bike climbs, as the rolling resistance is dramatically lower. What was less-expected was how well it did when we got onto real dirt, offering a surprising amount of traction. We kept running the Rock Razor all the way through the winter and it really impressed us. The ride that sticks out most was trying to get up an ice-covered fireroad. There were two us; one on the Rock Razor, the other on another semi-slick rear tire with a more diagonal tread. While the other semi-slick fishtailed and floundered, the Rock Razor quietly got the job done with a minimum of fuss. Of course a full knobby tire would offer more traction, but usually, we ended up feeling that our talent was letting us down before the Rock Razor did.Cornering:
This is what makes the Rock Razor so much better than any other semi-slick. The side tread is nothing short of awesome and, much like with the Magic Mary, you can lean the tire in and hold the bike firmly on the side tread. When you transition from centre to side tread, the difference in the tread profile means you can feel exactly when you get onto the side, which is a great help to manage traction. However, the Rock Razor may not suit less confident riders. To corner well with this tire, you need to lay the bike onto its side. Try to keep the bike upright and you will feel yourself sliding.
We ran the Rock Razor in all conditions and were continually impressed by how well it performed.
After riding the Rock Razor in the rear for a few months, we got complacent and dropped into one of the ultra-steep DH lines near our test area in Sospel. Once you get used to the tire's excellent grip when leaning the bike into corners, you can easily forget that it is still a semi slick. On the kind of steep terrain, where you need to use your rear wheel to control your speed, we found ourselves sliding out of control into the catch berms. It is a tire with limits and when you drop into that kind of terrain, you are asking for trouble. You need to think about braking with this tire and get it done ahead of time. We really like the combination of this tire on the rear, paired with a Magic Mary front (although we have heard reports than Brendan Fairclough runs them both front and rear on his trail bike in the off-season, but he clearly brakes a lot less than we do). We have spoken to riders struggling with this tyre when paired with a less-aggressive Nobby Nic front tyre and we do believe that you need a bigger front tire for it to work. All the traction for braking is coming from the front, so you'll need something more muscular than a semi-slick to stand up to the task. Again, these kind of constraints won't suit everyone. Lifespan:
We have been pleasantly surprised how long the Rock Razor has lasted. It seems to have a harder compound than some of Schwalbe's other offerings. Our current rear tire has been on the bike for nearly three months now and we are only just starting to think it may need to be retired. There isn't a huge drop-off in performance once this tire starts to age either. It may lose the sharpness of a fresh tire, but it still feels good out on the trail.Pinkbike's Take:
| Schwalbe's Rock Razor is not a tire for everyone. You'll need to be honest with yourself when you are considering the Rock Razor. If you are not confident leaning a bike into corners and braking precisely, then it is probably worth looking at a more forgiving option. As Nukeproof's Greg Callaghan says, "These tires will make a man of you." That said, we love it. Paired with an aggressive front tire the Rock Razor is a perfect combination for aggressive trail riders and enduro racers, and we have ran it all conditions with few misgivings. Schwalbe have produced a welcome evolution to semi-slick tyres. We expect the Rock Razor to be the most-copied tire of the 2014-2015 seasons. - Matt Wragg|