Reviewed: Shimano’s Dura-Ace C50 carbon clincher wheels

reviewed by Matthew Pioro

From deep, flat-inducing potholes to gravel roads, I pushed Shimano’s Dura-Ace C50 carbon clincher wheels hard. The hoops are built to withstand a lot, but I wanted to see just how much.

The rims are a mix of aluminum and carbon fibre. Alloy is extruded to create the brake track. Unlike some wheel manufacturers, Shimano doesn’t machine off the hard – and in some cases, structurally important – crust-like surface that forms after extrusion. The company creates a thin and strong aluminum section from the start. It then adds the carbon fibre, not only to create the aerodynamic rim profile, but for structural rigidity and vibration absorption. With aluminum and carbon fibre at work on the wheels, you get the benefits each material has to offer. With the alloy brake track, you have excellent stopping power, far better than on a carbon-fibre track, and can use stock pads to scrub speed. The carbon fibre is, of course, lightweight and highly tunable. While the alloy does mean the wheels weigh more than full carbon-fibre hoops, the braking power and control are worth the extra mass.

Shimano calls the C50’s rim profile D2. When D2 appeared on the 2013 wheels, it brought a more bulbous shape to the C50, in contrast to the V-shape rim of the earlier models, to help cut through the wind. The company says the 50-mm-deep profile reduces drag at yaw angles from zero to 15 degrees better than other aero shapes. I found the wheels behaved very well in a variety of conditions, even when the wind wasn’t coming from an optimal direction.

The hubs use cup-and-cone bearings instead of cartridge bearings. Cup-and-cone may seem like an older, less sophisticated technology, but it’s on Shimano wheels for well thought-out reasons. “We use cup-and-cone in all of our hubs because of their ability to offset loads placed on wheels,” said Ben Pye, technical specialist at Shimano Canada. “Cartridge bearings are designed to take an up-and-down load, like the prop shaft of a machine. They are not designed to work with something that has torsional loads, wind loads and cornering loads, which is what’s happening in a hub.” The cupand-cone bearings can offset the forces that come not only from riding in a straight line, but also cornering and rocking the bike back and forth when you are out of the saddle. Also, cup-and-cone bearings need much less servicing than cartridge bearings.

These wheels performed excellently on all the roads I took them down. I lucked out with a bunch of gravel rides while I had the C50s. The roads, of course, were a lot of fun. The wheels were up to the task of keeping me rolling on the rocks and ruts, as were the 25c Vittoria Open Corsa CX tires. The C50s are durable, but not at the cost of performance. Yes, you get a bit more weight with the aluminum on the rim and the cup-and-cone bearings. But every time you hop on these wheels, you’ll be able to push them hard.

SHIMANO DURA-ACE C50 CARBON CLINCHER
Rim depth: 50 mm
Materials: Carbon fibre and aluminum
Weight per set: 1,672 g
Hubs: Shimano Dura-Ace 9000
Price: $2,450
Website: bike.shimano.com