Next to tires, wheels are one of the most important components a person can pick to improve their bike’s ride. The right wheelset can make a bike accelerate faster, ride smoother, or steer better. Of course heavy, flexy or fragile wheels can make a bike feel much worse too. I’m happy to report that Crank Brothers’ new Cobalt XC are fast (light & stiff), tough (so far), and really, really nice looking.
I’ll admit that I was pretty confident I was going to order a set of the Cobalt XCs the moment I saw the early photos- before reading the accompanying text. When read more about them, I was even more convinced by their low weight, new spoke design and rim strip-free tubeless compatibility (which I think is imperative), and claimed strength- I was sold.
When the wheels arrived (we were on the company’s waiting list) I mounted a pair of the Schwalbe’s new Racing Ralph Evo UST 2.25 tires with no fuss and started riding. Prior to the Cobalts, I had been riding Fulcrum’s Red Metal Zero wheels and been impressed by their light weight and strength for what’s being called ‘trail’ riding. I mention this because the Fulcrums were fantastic- and the switch to the Crank Brothers wheels didn’t change the feel of the ride much at all- and that’s good. It’s possible that UST rims with about the same weight, quality and dimensions will feel similar no matter who built the wheels.
The Cobalt XCs seem fast when riding and, although I was still chasing the same fast guys I always do, I did feel a bit sprightlier. I could definitely feel the light weight when the wheels turned downhill though- they accelerate very quickly once you pass over the peak of a hill. In fact, I often had to rein them in long before I have to brake on some other wheels.
In order to create a hole-free, sturdy rim [without infringing on others’ patents], Crank Brothers have come-up with what they’re calling Twinpair spoke technology. Instead of attaching each spoke to the rim through a threaded hole [like Mavic, Shimano or Fulcrum], their rims are extruded with a central rib for a Y-shaped profile. This rib is pierced by little metal barrels to which a pair of spokes are mounted. The in the Cobalt XCs’ case, the rib is machined away between the spokes to save weight. There is also a central rib inside the rim itself [like WTB’s LaserBeam rims from the mid 1990s] to stiffen the rim vertically and resist the paired spokes’ tendency to try to collapse the rim. All of this allows the rim’s outer wall to be unbroken and therefore stronger and hold air without adding significant weight or requiring a sealing rim strip. To keep the user from having to remove rotors and cassettes to true the wheels, the nipples are long. Really long. See how the spokes are half blue? The blue halves are the nipples. It's weird, but it works (and makes the wheels bluer).
The other fun new thing about these wheels is the new quick-release design. Crank Brothers have split the quick-release lever into two halves. Crank Brothers claim that it takes less effort to release the lever if you pull one half and then the other. This is probably true but I usually don’t have a problem getting the quick-release lever undone. It may be a boon to all the weak-gripped mountain bikers out there- there must be a few who’ll appreciate the feature. I think that they look nice.
I have only about a hundred miles on them so far, but 60 miles of that distance was two rides of about 30 miles each. Both were punishing rides with a fair amount of wet thanks to New Mexico’s monsoon season. The second ride in particular was vicious, with a 10 mile downhill close to 6,000 vertical feet and filled with rocks, roots, mud, and water crossings. The other was a point-point ride on Taos’ South Boundary and Elliott Barker trails, featuring plenty of technical climbing, fast descents, torrential rain, lightning and hail. Other than some strange “pinging” noises from the spokes over slower technical sections that had me looking down to see if I had busted one, they performed flawlessly, and didn’t keep me from hitting some truly scary speeds on the descents.
After all this, the rear wheel was a bit out of true, but not bad. This is not something I consider a problem on new wheels after some hard use- most need a slight “tune-up” after some early mileage. I’ll have them trued at my local shop and imagine that will be that. If they don’t stay true, that could be an issue and I’ll post that in a later report.
The Cobalt’s are advertised as weighing 1540 grams and mine came out very close to that at about 1550 something grams. That is very light for a tubeless wheel that can handle the kind of rides that it has proven it can. They have a two year warranty and retail for a whopping $1,000.00. I like them and will post an update as I get more miles on them.