Redesigned for 2012, the Crossmax SXs are Mavic's 'all-mountain' option. They're daily drivers, handling both long cross-country rides and rowdy descents with aplomb, and they've stood up well to six months of testing, including use in two enduro events. For aggressive trail riding they're hard to beat, but they need a wider rim to truly live up to their 'all-mountain' billing.
The SXs are just right in a lot of respects. They feel stiff when steering and pedaling yet have enough give that they don’t pinball off of every trail obstacle, with the big, round Zicral spokes adding to the lively ride feel.
At 1,787g (with valve stems but without front 20mm axle and rear quick-release skewer) they're reasonably light, too. In fact, when pedaling cross-country, they don’t feel appreciably heavier than their lighter cousins, the Crossmax STs – and we’ll happily take the wider rim and couple of extra spokes.
We haven't pulled any punches with the SXs, either. We've ridden them on all types of terrain from straight up, buffed out cross-country to lift served enduro racing and even an underground hammer fest on some of Moab, Utah’s burliest, most testing terrain. They've taken jumps and medium sized drops in their stride, and have even stood up to drops in the 8ft range (with transitions).
Mavic's Crossmax SXs are great daily drivers and worthy of enduro and Super D racing, too
The rims have a few dents in them, but we've not found any sign of cracking or serious damage. Midway through our testing we were able to unhinge one of the Zicral spokes from its hook style hub mount, but after reattachment and a quick check of the wheel’s tension, we took back to the trail without further ado. The wheels continue to run true.
Mavic say they've had no problems with spoke ejection in the previous SX or in testing of the 2012 model (they polled lab and field testers as well as the sales force). In fact, they say our experience is the first they've heard of the issue. They've chalked it up as an isolated incident and have no further explanation.
The only other issue we've had is with braking noise—a set of our Shimano Saint discs (203mm front/180mm rear) that run silently on other wheels begin to howl during extended bouts of braking on the Crossmax SXs, however, other brakes with smaller rotors (180mm/160mm) didn't produce the same noise.
Possible explanations include, but aren't limited to, the painted rotor mounting surfaces or the design of the new, lighter hubs. While annoying, it has no obvious effect on performance. On the subject of that striking new white painted finish, we'd rather Mavic had stuck with anodizing.
Mavic's SX hubs are painted white – could this explain our problems with brake howl on long, steep descents?
White paint tends to be heavier than other colors, as more coats are needed. Switching to a different finish would save a few grams and, since the wheels already ride light, Mavic could put the weight right back in with a wider rim extrusion. As it is, the 21mm (internal width) rims are solid with a 2.3in tire and wide enough to keep a 2.5in tire from rolling around too much. But we'd take them wider if given the option.
Mavic's mountain bike product manager, Manuel Berschandy, told BikeRadar that the paint adds less than 15g per rim. "We chose this option because the weight penalty is minimal on a wheel like the SX, which will be fitted with heavy tires in most cases," he said. "That is, however, not something we can tolerate on race-oriented wheels like Crossmax SLR. Given the feedback we already have, the look is worth the small added weight."
As for rim width, Berschandy told us Mavic opted for 21mm for two reasons. "One: the weight of the rim would have increased with the same profile and the same finish," he said. "We already have some extra weight with the paint but that doesn't mean we don't pay attention to the rim weight, which has a huge impact on the wheel behavior and performance.
We put a slight dent in the rear rim
"Two: with the current 21mm rim we're confident, thanks to top riders and field tester feedback, that the shape given to the tires is optimal – not too cubic, not too round – for those tires that measure 2.3 to 2.5in. So there's no need for wider rims. Our downhill race wheels, the Deemax Ultimate, are also 21mm internal and our downhillers love them and never complained about the wheel being too narrow."
Width aside, the true UST rim with its new bed profile makes quick work of mounting and inflating both UST and non-UST tires tubeless, even with a standard floor pump. The hubs are uber-compatible, accepting 15mm and 20mm front through-axles, as well as 9mm quick-release, 135mm- and 142mmx12mm rear through-axles. The front adaptors and rear 142mm adaptor come standard, while the 135mm adaptor is sold separately.
The ITS-4 freehub is noticeably faster than some of Mavic’s competitors, and we've had no issues with it becoming sticky or slow. The steel cartridge bearings in both front and rear hubs have run exceptionally smoothly – better than some ceramic bearings we’ve used.