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by James Huang
April 13, 2018
Photography by James Huang
TECH NEWS BROUGHT TO YOU BY BIKEEXCHANGE
The Schwalbe X-One Speed fills the gap between the dirt road-friendly G-One Speed, the ultra-popular G-One Allround, and the aggressively knobby X-One Bite. Schwalbe says its latest mixed-surface tire is a “speed miracle” on dry tracks with stable cornering characteristics thanks to its progressive tread design, but how well it lives up to that billing depends heavily on carefully dialing in your pressure.
Many will view the X-One Speed as yet another gravel option from Schwalbe, but the company intends it more as part of a three-model range aimed more specifically at cyclocross, with the X-One Allround in the middle, the more aggressively treaded X-One Bite for mud and softer ground, and now this new one for harder surfaces. The model name itself should perhaps be the biggest clue about that aim, but it’s also evident in the sizes offered. While the multi-surface G-One Speed and G-One Allround are both available in a generous range of widths, both the X-One Speed and X-One Bite are only available in a UCI-friendly 33c casing.
Nevertheless, the X-One Speed borrows some elements from the ultra-versatile G-One family, such as the casing construction and the round, low-profile knobs that are tightly spaced down the center of the tread. As with the G-One, the idea with that distinctive pattern is to provide a modicum of extra grip for more dependable drive and braking traction when upright, along with the surprisingly low rolling resistance that has characterized the G-One family.
The Schwalbe X-One Speed wears a very interesting-looking tread design that aims to combine straight-line speed with reassuring cornering traction.
Schwalbe pairs that speedy center tread with knobs that get more aggressive as you move outward from the center. At the very edge is an array of 2.5mm-tall dash-like blocks, while the tapered transition knobs in between resemble little rubber doorstops. And although the X-One Bite also uses a progressive knob design, the change in height from 3mm in the center to 4mm out at the edge is far more subtle than it is here. If you’re a mountain biker who was around in the late-1990s and wondering why the tread seems so familiar, it’s very similar to what Bontrager once did with the Revolt SS.
The X-One Speed may only be produced in a single width, but Schwalbe does produce it in two casing constructions. The top-end Evolution model tested here sports a “Tubeless Easy” 127TPI nylon casing and thinner Microskin casing reinforcement for more suppleness, while the mid-range Performance variant makes do with a less pliable 67TPI casing, a tougher RaceGuard protection layer, and tube-type construction.
| Related: Clincher, tubular or tubeless tyres?
Interestingly, claimed weights are the opposite of what you’d expect, with the X-One Speed Evolution coming in at 370g each, and the cheaper X-One Speed Performance supposedly tipping the scales at a slightly lighter 350g (although the total weights will flip again once the mass of an inner tube is added to the Performance version). Actual weight for my pair of Evolution test tires straddled the claimed figure at 361g and 391g apiece — roughly on-par with claims, but with more variation than I’m used to seeing these days.
The center knob pattern is highly reminiscent of Schwalbe’s ultra-popular G-One Allround with its tightly spaced array of round dots. The tread height gets progressively taller as you move further out toward the sidewalls, though.
Retail price for the X-One Speed Evolution is US$80 and the X-One Speed costs US$48. International prices are to be confirmed.
As with every tire, the X-One Speed comes with a recommended range of inflation pressures, which in this case is 40-70psi. I’m no stranger to running tubeless cyclocross tires, though, having made the switch from tubulars to tubeless full-time more than six years ago. Pressures in the low-20s have historically presented few issues for my 70kg frame, but seeing as how my testing of the X-One Speeds would include some rocky terrain, I initially went with what I thought was a fairly conservative 35psi.
At that pressure, the X-One Speed felt anything but speedy. In fact, it was notably slow and sluggish, with disappointing levels of rolling resistance from the not-so-supple casing. Worse still, I found the cornering grip to be a bit lacking as well. Whereas the larger G-One Allround models can rely on their generous casing widths to provide grip on a wide range of surfaces, the X-One Speed instead has to lean — literally — on its knob design, which, at least to me, didn’t seem sufficient to close that gap in footprint size.
The semi-stiff casing works better at slightly higher pressures as it helps keep the slower-rolling transition and shoulder knobs off the ground when traveling in a straight line.
Some tires are more sensitive to changes in pressure than others, however, and as it turns out, the X-One Speed is one instance where you’re much better off paying heed to manufacturer suggestions.
At 40psi, the tire’s performance is transformed, and much more in keeping with expectations.
With a bit more pressure to help the casing maintain its shape under load, the transition and cornering knobs don’t come into play as much when you’re upright, and so the rolling resistance feels much more inline with the G-One Allround — one of my absolute favorites for mixed-conditions riding. And when you lean the X-One speed over at those slightly higher pressures, the additional casing support also helps push the shoulder tread into the ground better for more surefooted traction through soft corners.
The dash-shaped shoulder knobs are nearly continuous, and provide a decent “shelf” on which you can lean during hard cornering.
Even better, the squared-off profile also provides more of a “shelf” to lean on relative to tires with more rounded profiles, which I found especially useful when the ground was particularly loose. That sort of profile is more amenable to controlled drifting through slippery corners than the rounder G-One Allround, too, which is more prone to sliding out when pushed past its limits.
As has been my experience with other Schwalbe mixed-terrain tires, durability of the X-One Speed has been pretty good, and both samples were easy-as-pie to set up tubeless, requiring only a high-quality floor pump and about 30cc of sealant to get them seated and sealed.
In fairness to Schwalbe, the X-One Speed is a solid option when viewed in the intended context of cyclocross racing. It’s pretty fast and offers good cornering grip, and for privateers that actually have to pay for their own equipment, the hard-wearing durability is refreshing.
However, I’ve never been a big fan of semi-stiff cyclocross tires for high-performance applications, regardless of rubber compound or tread design. While they can be made to roll quickly and grip well, it always feels like a compromise as compared to tire carcasses that are inherently more apt to conform to the ground. Tread design is important, but footprint size is arguably more so in many situations.
Addix is the terms Schwalbe uses for its custom rubber blends. Whereas the upper-end Evolution model gets a single-compound formula, the mid-range Performance model gets a dual-compound tread cap.
The higher pressures the X-One Speed seem to demand for optimal performance also compromise ride quality, and despite claims, it isn’t actually UCI-legal in terms of size. Actual width on a 21.5mm-wide rim at 40psi is 34mm on the nose, and unless you’d prefer to mount these tires on rims with fairly narrow internal widths (which I don’t recommend), you stand the very real possibility of running afoul of race officials at the starting line.
In light of all of that, I like the X-One Speed, but I don’t love it.
For cyclocross racing, my money is still on the tried-and-true Donnelly (née Clement) PDX/MXP/LAS trio, all of which have noticeably softer casings and better grip in questionable conditions, as well as what feels like a faster roll at a wider range of inflation pressures. Tread durability seems about even between the two brands, too, and while the X-One Speed has the edge in terms of casing durability, the modest casing volume limits its usefulness for everyday riding.
The profile is quite squared-off for a mixed-surface tire, which is good for softer ground, but makes for vague cornering on asphalt.
If an all-purpose mixed-terrain tire is what you’re after, I’d go with Schwalbe, but not this particular model. Instead, I’d recommend the more versatile — and truly superb — G-One Allround in a 35c or 40c size, depending on what will fit in your bike. The larger casings provide ample cushioning, while somehow offering nearly as much cornering grip as this X-One Speed (unless the ground is very loose), a more natural feel when cornering on pavement with its more rounded profile, and a faster roll overall.