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Shimano XT All Mountain wheelset
by Phil on 16th January 2008
Gravity works both ways, as I've been finding out for the last couple of months. The downs might not be more fun when you've 'earnt' them but a bit of XC keeps you sharp in the off season. But no-one here wants one of those skinny blokes bikes so I've been rocking this proper 'am' wheelset to see if it takes the Peak District hits.
In the old days, when men were boys and (masters riders were younger men), the options for complete wheels were slim. If you wanted a decent wheelset, you specced out a fancy custom build yourself. Looking over the photos from Interbike last year, things are changing. Custom wheelsets are the new black - and now the 'big S' are in on the act.
For 2008, Shimano have revamped the XT groupset and now offer two complete wheelsets in the range. As most of our readers tend to the 'burlier' side of riding, we got hold of the All Mountain wheelset to hang on the Meta and put through the wringer.
These hoops are made from 26.4mm wide UST rims, laced with 24 straight spokes onto Shimano's own XT hubs with centrelock rotor fitments. The front hub features a 20mm bolt thru for added stiffness and compatibility with the increasingly common bolt-thru all-mountain forks (Pikes, Lyriks etc). Being UST, they can be set up tubless very easily.
The graphics are striking - black components offset by red details with 'aggressive' rim stickers (which look a million dollars when they are spinning fast!). Looks are personal so check out our review gallery and make your own mind up!
Weight is bang on for the application with the all up weight quoted at 2050g (bare wheels only). Measuring up against my Bulb/Mavic/DT combo, the front came in at 1160g, including centrelock rotors, versus my Bulb/521CD and 6-bolt rotors which pegged 1198g. 38g in favour of Shimano.
The rear, on the other hand, was 1244g versus 1416g, Shimano saving 172g and adding up to a total saving of 210g (almost 1/2 lb) for the Bulb/Mavic/DT pair. Most of this is in the hub and a Pro II may well close the gap.
Where the XTs score big time on the weight front, though, is that they are UST compatible from the get go. More on tubeless on page 2...
24 spokes not only offer lighter weight (a mere 8 spokes and nipples may not be enough to get really excited about) but also offer less wind resistance. Since each spoke has to cut through the air as the wheel spins, dropping spoke count can help reduce wheel drag. My roadie colleague explained the top of the wheel is going twice as fast as you are (them roadies love this kind of thing!). This extra drag makes a big difference to the lycra crew and now the 'AM' crew can benefit too.
Straight pull spokes on the castellated rear hub
Shimano have opted for straight pull spokes on this wheelset. I'm not normally a fan. Since there's no elbow to provide a 'torque reaction' during truing, the result is that the spoke often spins at the seat instead of the nipple, making them a real bugger to tighten. However, Shimano cunningly forge a flat into these spokes, near the nipple, and provide a slotted spoke key to use like a spanner. This detail actually makes the wheels easy to work on as you can remove all tendency for the spoke to twist under load.
Hex nipples and dedicated spoke key
Another welcome tweak is the hexagonal alu nipples. Aluminium saves a few grams at the most important place on the wheel, but the traditional square nipple tends to round off really easily. With more meat and increased contact area, the hex is much better. Just don't expect to borrow someone else's spoke key on a ride, pack the one provided!
The whole lot spin on some reasonably light and dependable XT hub shells that use Shimano's preferred loose ball and cup and cone setup. These angular bearings are well sealed and adjustable, should the need arrise. To help the smooth spin, small counterbalance weights are brazed on the rim opposite the valve stem! Cool attention to detail.
Centrelock rotors on the 20mm bolt through front hub
It's no surprise that the hubs require the proprietary Shimano centrelock rotor system. I was a bit biased, but in use these make a lot of sense. Locking is achieved with a cassette tool, or a hollowtech bottom bracket tool for the 20mm front hub. This system ought to be more secure and fitting rotors is a breeze. Removal will be simple too so next time I fly with the bike, I'll just whip them off. Centrelock to 6-bolt adaptors are now available too.
Overall the XT wheelset is very well specced, nicely put together and a respectable weight. Read on to see how the hold up to a battering and hear about my fun with latex.
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