At 1260g with carbon spokes, Hunt’s Proven Race XC UD Carbon wheels sound like a time bomb for regular trail use. The only thing these super light, super responsive wheels have blown up in a year of testing though are my worries and my mates’ legs. That puts them right at the top of our best XC mountain bike wheels leader board for racers and fast riders with one eye on the prize… and the other on the price.

Hunt Proven Race XC UD Carbon need to know

• Under 1270g – measured – for a taped and valved pair
• All new super light, front and rear specific 30mm internal carbon rims
• UD carbon fibre spokes are ultra light but 30% less stretchy than steel
• New S_RapidEngage 90T free hub system has only two degrees of lag
• 29er only but compatible with tires from 2.0 – 2.6mm
• Lifetime ‘H_CARE’ crash replacement warranty

Bladed carbon chops the weight of a standard steel spoke in half, and the reduced count (20 and 24 front and rear respectively) helps slice the weight down too

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Design and specifications

The bladed UD (UniDirectional) carbon fibre spokes are the big headline with the Proven Race XC UD Carbon wheels. Despite weighing just 2.7g per spoke (the industry standard Sapim CX Ray steel spokes are 4.4g) they have 30% less elongation under load than steel.

And unlike some monocoque carbon spoke wheels, tension can still be adjusted conventionally via the alloy nipples. They’re easy to replace too, not that I’ve had to so far.

The Provens are front and rear wheel specific with more compliant carbon and fewer spokes up front

The wheels themselves are front and rear specific, both have carbon rims with a 30mm internal rim width, 36mm external width and 22mm depth with a hookless edge and H-Lock bed profiling for a secure ‘pop’ into place.

The front wheel only has 20 spokes though and a lighter (348g), more compliant carbon construction. The rear wheel has 24 spokes, and a tougher, stiffer 369g rim. That brings complete wheel weight down to 1,266g for our set.

That low weight has recently been eclipsed by the latest sub kilo Specialized Roval Control World Cup carbon spoked wheelset, but at £2,500 they’re almost double the price. So are the Bontrager Kovee RSL wheels, which are a comparable 1,245g weight; and the Syncros Silverton SL; and DT Swiss XRC 1200 wheels, which are actually heavier. Meanwhile more price matched options like the Reserve XC28 and Mavic’s CrossMax SLR are significantly heavier, at 1480g and 1570g respectively.

Hunts new hubs have two degrees of engagement, which means there’s virtually no lag between stomping on the pedals and accelerating

Hunt’s latest S_RapidEngage MTB hubs use a 90 tooth driver ring and 3×2 double tooth pawl clutch. The remodelled rear hub uses ultra low friction EZO bearings, a reinforced axle and enlarged drive side flange to equalise spoke tension.

Centrelock rotor mount comes as standard, but you can switch to traditional 6-bolt if you like

The wheels are only available in 29er but that’s fair enough for the intended XC audience. The centerlock rotor mount can be adapted for 6 bolt and you can choose SRAM XD, Shimano MicroSpline or Shimano HG free hub bodies when you order.

The wheels come pre taped for tubeless tyres with Hunt valves and a signed hand wheel building card in the box. You don’t get spare spokes in the box though, so you’ll have to wait for Hunt to post you some if you do snap one.

Seating even the most flexible XC tyres is easy on the Proven rims, where the tyre bead is pinched together to hold air

Performance

The valves and the H-Lock ridges in the rim bed make inflation easy, pinching the base of the tyre together for a better seal. That makes them much easier to get tyres onto or off than the flatter, fat-edged Roval Control wheels that are an obvious competitor.

They’re easier to swap tyres off than the asymmetric Reserve XC28 rims too. Just prepare for a potentially frightening bang as they hop from the H-Lock to the outer rim edge to seat properly. Upgrading to high flow valves would make inflation even easier too as the supplied set is conventional Presta style.

Presuming you’ve used a suitably light tyre the acceleration gains of the Race XC UD wheels are as dramatic as they are obvious. Not only through the reduced mass but also the essentially instant freehub pickup and taut feel of the carbon spokes. Not only will they gift you an extra gear when kicking hard, they also make it easier to flick and kick around if you want to add some steeze to your speed. The super fast bearings and bladed spokes keep things rapid even when you’re just rolling or pumping too.

I’ve been riding these wheels for months now, and I’ve given up being surprised that they’re still on one piece

XC racing is no longer about hyper velocity at the expense of a hysterical breakdown when things get tech though, and the Hunt UD’s reflect that really well. A lot of superlight wheels I’ve ridden compensate for a low spoke count with super high tension that sends you skittering and skipping across the trail rather than gripping. High stiffness can also hammer the momentum out of you on those dreaded lumpy field sections that haunt most race tracks.

However, despite the less stretchy spokes the re-profiled rims of the UDs are positively calm and settled in comparison. If you know your wheel feel, they’re noticeably less high strung than Syncros, Roval and DT Swiss options, with a surefooted grip and footprint more like Reserve’s XC28s or Zipp’s Hi-Top wheels.

Or to put it simply, they ride like really well-balanced, predictable wheels and if you’re running RockShox forks you can add Torque Caps for extra accuracy at the front.

While the rim top flange isn’t as dramatic as Roval’s Control wheels, I’ve regularly rolled out of clattery jank situations and am very surprised that the tyres are still inflated too. The rims themselves are totally fine as well, with occasional white marks wiping away with relief after rock strikes.

There’s no sign of bagginess in the spokes, despite proper trail bike use

Cynics will be disappointed to hear that after a full year of hammering the spokes are all still completely intact with no obvious wounds or loss of tension. For full disclosure I’ve not managed to knock a rear mech into them at speed or fully locked them with a skewered log, which might well be the end of them – as it would metal spokes.

However I’ve bounced plenty of sticks and stones off both wheels and generally treated them like a full on trail wheel, not a lightweight exotica, and they’ve never glitched or flinched once. If you do snap a spoke they’re replaceable with a standard steel one until Hunt sends you a spare too. The reinforced rear axle hasn’t snapped like older Hunt axles can and those fancy foreign bearings are still spinning quietly and smoothly.

The best blend of weight watching, strength and cost? Hunt could just be Proven right (sorry!)