WTB CMR Light i30 Wheels: First Ride

WTB CMR Light i30 Wheels: First Ride

Can a 1,300g XC wheelset keep durability high on the priority list?

The world of XC wheels is a crazy rabbit hole. Start looking around and suddenly you are comparing grams, spoke counts, bearing sizes, and how much money you can justify spending before you have even bought tires. We get it. But a low number on the scale is only part of what makes a wheelset worth riding.

WTB's new CMR Light i30 wheels pair a claimed 1,300g wheelset weight with 30mm internal carbon rims and the brand's new Frequency 7X hubs. At $1,800 for the pair, they're aimed squarely at riders looking for a light, fast XC wheelset. I've managed to get a few rides on them aboard my Revel Ranger, and while the low weight was expected, the stiffness caught me by surprise.

What's New?

WTB has been making bicycle components since its beginnings in Marin County in 1982. Tires and saddles might be what first come to mind, but wheels, rims, and hubs are very much part of that history. The CMR Light adds a dedicated lightweight mountain bike option to the brand's carbon wheel lineup.

The recipe starts with 29-inch carbon rims, 24 spokes per wheel, boost hub spacing, and centerlock rotor mounts. WTB lists the front wheel at 609g and the rear at 691g, putting the claimed total at 1,300g. TCS tubeless tape and valves come installed, saving you a couple of steps before mounting tires.

What interests me is how much attention WTB has given to durability and serviceability alongside the low weight. Larger bearings, reinforced spoke beds, and a different way of securing the hub's inner ratchet ring all feature here. I like a light bike, but I also want to keep riding it once the trail gets rough. Those details are worth a closer look.

Carbon Rims With More Than Weight in Mind

The CMR Light uses a 30mm internal rim width, giving modern mountain bike tires a broad foundation. WTB pairs that width with a hookless profile and wide upper rim legs designed to help protect against pinch flats. The asymmetric rim shape, reinforced spoke beds, and 4D spoke drillings are intended to improve load distribution through the wheel.

WTB says it has tuned vertical compliance into the rim while retaining lateral stiffness for precise handling and hard cornering. In theory, that means a wheel that responds when you stamp on the pedals or push hard into a turn, while taking some of the sting out of rocks and roots. As I'll get into below, these definitely lean toward the stiff end of the wheels I've ridden.

The rims also use WTB's TCS tubeless technology. With the tape and valves already installed, all that's left is to agonize over which tires to run. That part usually takes me longer anyway.

Frequency 7X Hubs

The new Frequency 7X hubs have already seen World Cup success with Cannondale Factory Racing's Luca Martin, including overall XCO and XCC titles, according to WTB. Race results are great, but I'm mostly interested in what's going on inside.

Inside, WTB uses a ratchet drive system with a DLC, or Diamond-Like Carbon, coating on the ratchets. WTB says the coating provides greater hardness and lower friction than traditional hard chrome-plated drive systems. The inner ratchet ring connects to the hub through splines instead of threads, with WTB claiming that the interface can withstand more than twice the torque of traditional threaded designs while simplifying service.

Larger-than-typical Enduro bearings are also used throughout. WTB claims the freehub bearings offer up to a 38 percent higher load rating per bearing compared with competitive rear hubs. The larger bearings are intended to create a stiffer axle assembly, improve reliability, and extend service intervals. Bearing load ratings do not tell us exactly how many wet rides a hub will survive, but the emphasis is encouraging.

First Rides

I've been fortunate to get a few rides in on the CMR Lights, and they've already surprised me. Right out of the box, the wheels are ready for tires, with rim tape and tubeless valves pre-installed. On my scales, the total wheelset weight was 1,309g, just 9g over the claimed weight.

WTB sent over a 120 TPI Peacekeeper/Macro tire combo to test with the wheels, but with my Revel Ranger in more of a downcountry mode at the minute, I wrapped the CMR Lights with my go-to small-bike tires, the 60 TPI Peacekeepers. Both tires seated straight away with just a floor pump, a small but pleasant detail. I ran 22 psi in the front and 24 psi in the rear, with no inserts.

Within seconds of reaching dirt, I could tell how stiff these wheels were. I've spent some time on WTB's earlier CZR i30 enduro wheels and was familiar with their reputation for stiffness. Still, with only 24 spokes and so much emphasis on how light the CMR Lights are, I can't say I was expecting that initial ride feel.

Climbing is a dream with the CMR Lights. As expected from a 1,300g wheelset, every bit of power feels like it propels you up the climb. Even with the heavier 60 TPI Peacekeepers, these wheels felt light and snappy, rolling well and accelerating quickly out of corners. I did get some spoke pinging, particularly while climbing steep, techy singletrack where my pedal stroke gets a little more uneven and torque-y. The wheel stayed true, and there weren't any loose spokes after a few rides, but it's definitely something I'll keep an eye on as I put more time on the CMR Lights.

Descending, you can immediately tell these wheels were designed to be light, fast, and competitive on a racecourse. The CMR Lights feel fast and precise, with plenty of feedback telling you exactly what your wheels are hitting and when. Some riders will welcome that sensation, while others will crave more forgiveness. I tend to find myself in the stiff-wheel camp, particularly because I like to corner hard and feel the bike drive forward out of the turn. Even then, the CMR Lights were at the upper end of my stiffness preference. They felt really locked in and efficient on smoother, flowier trails, but bordered on a touch too stiff and prone to deflecting through the really chunky, chattery stuff.

I've only had a few rides on these wheels, but I'm planning on getting a few months of XC shredding and downcountry bashing in to really put them to the test.

Ride With Confidence Guarantee

WTB backs its carbon rims with its Ride With Confidence Guarantee. According to WTB, if you break a WTB carbon rim while riding and you are the original owner, the company will send you a replacement rim for free. No exceptions.

That is reassuring when you're spending $1,800 on a wheelset, especially one this light. The guarantee is for the carbon rims, so don't read it as free replacement of every part of the complete wheel. Still, it's nice to have that support behind something I plan to put plenty more miles on.

What's Worldwide's Takeaway?

WTB has put some real time and effort into the CMR Light i30 Wheelset. Mine came in at 1,309g, mounted up without any drama, and felt light and snappy on the climbs even with my heavier 60 TPI Peacekeepers. I also like seeing serviceability and bearing capacity get this much attention in a wheelset built around speed.

The biggest takeaway from my first few rides is just how stiff these wheels feel. I generally like that direct, precise feeling, and the CMR Lights felt really locked in when I was pushing through smoother corners. On the chunky, chattery stuff, they were right at the upper end of what I find comfortable. If you like a stiff, racy wheel, there's plenty to get excited about here.

I'm looking forward to putting more time on them and seeing how everything holds up, including whether that spoke pinging settles down. For now, the CMR Lights feel very much at home chasing speed, whether that's between the tape at an XC race or sprinting out of corners on the local loop.