Shimano’s built-wheel program has been very successful in the road racing market, but, until now, its paired-spoke hoops did not catch the attention of top-level off-road racers. Today, Shimano put the hurt on its competitors in the mountain bike market when it announced their first wheelset to carry the XTR moniker–and their first tubeless wheelset. Code-named the “whm 965,” the XTR wheels weigh a scant-1650 grams a pair. The hubs are CNC-machined items that carry the spoke nipples in lobes (the reverse of conventional flange-type hubs). Shimano increased the spoke count of the XTR wheels from the 16 it used on its 2002 off-road wheel line to 24. The “paired” spokes hook into the side of the rim to provide increased lateral stiffness.
DISC BRAKE HUBS
Shimano’s hubs use a titanium axle and freehub body, in addition to the “Center Lock” splined brake rotor interface to keep the weight of the hubs to the absolute minimum. Published figures are 150 grams for the front and 310 grams for the rear hubs. The semi-aero profile rim is said to weigh 400 grams.
TUBELESS COMPATIBLE
Shimano is happy to announce that the XTR wheels will mount up to all UST type tubeless tires and they are also compatible to conventional tube-type tires. The buzz is that Shimano didn’t bother to receive official UST approval, but it would be suicide if the XTR wheels didn’t operate as well or better than Mavic’s original UST rim design. As far as we can see, the UST group should be happy that Shimano put its weight behind the tubeless tire movement–which, after faltering at bike stores, has gained much momentum among cross-country racers in this country.
WHAT WE EXPECT
Presently, the splined rotor interface of Shimano’s XTR wheelset will only fit XTR disc brakes. Shimano has yet to announced if it will share Center lock technology with other disc brake makers. This is the only fly in the ointment. If Shimano allows competing disc brake makers to produce XTR-compatible rotors, the wheel will surely be a success. Technically, the addition of eight more spokes to Shimano’s paired-spoke design will resist the additional stress and spoke “wind-up” that hub-mounted disc brakes impart on a wheel. Nobody has mentioned a retail price on the XTR wheelset. Barring future sticker-price shock, it’s all good news for mountain bikers.
