For 2015 Shimano completely redesigned their XTR wheels. As with the previous version, they are offered in both Race and Trail flavours. The Race version provides a 20mm inner width. We opted to test the wider Trail version which measures 28mm externally and 24mm between the bead hooks—not super wide but it’s enough to support to a good sized trail tyre.
Our 29er test wheels
weighed in at 1,726g (795g/931g) which is around 50g over the claimed figure
(the Race version is around 100g lighter).
The most obvious
difference with the new wheels is found in the rim. From the outside you’d think
it was all-carbon but it’s actually alloy with a carbon outer wrap. The inner
alloy extrusion is thinner than usual while the outer carbon layers add
stiffness.
These rims have a
tubeless compatible profile but the inner surface is drilled, so tubeless rim
tape is required (they come pre-taped). Tyre fit seemed on the loose side. This
makes tyre removal easier but you’ll probably need a compressor and a bit of
patience to get certain tyres to mount.
GETTING GREASY
The package is held
together by 28 straight-pull spokes and some very lustrous smoky looking hubs.
As with all Shimano wheels, they utilise ‘cup and cone’ bearings. Shimano says they
are better at handling side loads than the more commonly used cartridge bearings.
We suspect this is true but the design presents a number of pros and cons.
On the plus side they
are entirely user serviceable. With the correct size cone spanners, you can
entirely strip and rebuild the hub with fresh grease. While you can repack cartridge
bearings, it’s often less successful and many people treat them as a disposable
item. There are more individual balls inside than with a typical cartridge
setup and you generally get better control over the bearing preload—it requires
a deft hand but you can get them spinning just right.
The negatives are that
it’s a bit fiddly to work on. Some of the balls run loose in the cup, so you
need to take care not to drop them on the workshop floor. With the ability to
fine tune the bearing preload comes the chance that you’ll stuff it up; too
much preload will kill your investment quick smart. And finally, the cones and
balls are replaceable but wear the inner bearing cup and the hub is toast. We
pulled our hubs apart at the end of our review and the grease was still looking
pretty fresh, so the sealing certainly appears to be up to the task.
There's no
adaptability with these hubs; the front is 15x100mm while the rear is 12x142,
they are the only options with the Trail wheels. They are made for Centre Lock rotors;
there’s no six-bolt option although some companies make aftermarket adaptors if
you need them. As you’d expect, the freehub is Shimano only (10 or 11-speed).
There’s no SRAM XD Driver option and they no longer offer a 26-inch option.
On the trail the
wheels proved sufficiently stiff and surprisingly robust. The 2mm thick bead retaining
hooks look a little dainty but they I didn’t sustain a single dent. The rear wheel
did go out of true by 2mm or so but it straightened up after a quick whirl in
the truing stand.
The freewheel mechanism offers 36 engagement points, which is on par
with most high-end wheels, offering good control on technical trails. We also
appreciated the titanium freehub body. It didn't show any signs of gouging on
the cassette splines—it seemed far more robust than alloy.
Retailing for $1,670 they sit at the upper end of what you’d expect to
pay for a high-end alloy wheelset but they are cheaper than carbon. You still get
the cool carbon rim looks and they proved to be a reliably tough all-round
trail wheel.
