Long-Term Test: Shimano Dura-Ace R9270 C50 Wheels

After already testing the new Shimano Ultegra wheels over 2,000 km last winter, we put the new Shimano Dura-Ace R9270 C50 wheels to the test over almost five months and in all conditions. Very versatile high-end wheels that prove extremely reliable.

By Guillaume Judas – Photos: Vincent Lyky / 3bikes.fr

At the same time as the new 12-speed Dura-Ace and Ultegra Di2 groupsets, Shimano presented new wheels at the end of last summer, in both product tiers and with 36, 50 and 60 mm rim profiles. These wheels are touted as more aerodynamic than the previous range, lighter and more responsive. For the 50 mm deep tubeless wheels tested here, for example, Shimano claims a 5.1-watt reduction in aero drag compared with the previous C40s, and even 1 watt better than the old tubular C60s, thanks to the shape and width of the rims. In terms of weight, we weighed the C50s at 1,487 g per pair, about 130 g better than the previous C40s. In the tubular version, the C50s would even drop to 1,332 g, which is very impressive for this rim depth. In the same configuration (50 mm, tubeless), the Ultegra wheels come in at 1,610 g.

This weight saving comes, however, with a wider rim, with an internal width of 21 mm and an external width of 28 mm, in line with current trends. This allows wider tires to be fitted and, above all, gives them excellent seating on the rim. The actual tire width depends on the brand and model, but with Michelin Power Cup 700×25 for example, the measured tire width is 27 mm on the Dura-Ace wheels. A very good compromise between efficiency, grip and comfort, and also aerodynamically, since the tire sidewalls ideally extend those of the rim.

Wheels compatible with 12-speed only

The new Shimano Dura-Ace wheels feature new hubs, 45 g lighter, that keep extremely reliable ball and cone bearings. They are fitted with a Direct Engagement freehub body which, according to Shimano, makes it 63% faster to respond when accelerating again after coasting. This system uses two toothed rings that mesh into each other, rather than a pawl system.

Additional micro-splines on the freehub body let the sprockets engage perfectly with the freehub, increasing the torsional stiffness of the wheel during accelerations. As a result, the body is only compatible with Shimano’s new 12-speed cassettes, unlike the Ultegra, which are compatible with 12-speed cassettes but also 11- and 10-speed ones. As for spoke lacing on the front wheel, it is 1:1 (the same number on each side), with 2.0-1.5-2.0 mm spokes to save weight. The rear wheel, for its part, has a differentiated 2:1 Optbal spoke lacing.

Aesthetically, the Dura-Ace (and Ultegra) rims now adopt a matte finish, with more discreet logos than the previous versions. It looks good and goes with anything, but this type of finish is fairly sensitive to dirt and the grease stains that come off the drivetrain.

Finally, in terms of price, the new Dura-Ace wheels have a retail price of €2,099 for all models, whether for 36, 50 or 60 mm rim heights, for tubeless or tubular versions, and even for the rim-brake versions (tubular only).

Five months on two different bikes

While we first got acquainted with the Dura-Ace R9270 C50 during the first test of the 12-speed groupset, including a mountain outing, the first real assessment over several weeks dates back to the test of the Orbea Orca Aero at the start of 2022. Then, from the end of March, we had a second pair of wheels fitted on our usual bike. All in all, we rode nearly 10,000 km with two pairs of wheels and two different bikes, in very varied conditions.

The first thing to point out is that the wheels do not always behave exactly the same way depending on the bike they are fitted to. The Orbea Orca Aero is a bike with very sculpted tubes, very stiff and not especially light. With this setup, the Dura-Ace wheels stand out for a liveliness that partly counterbalances the stiffness of the frame. They are very responsive when accelerating, and fairly easy to get back up to speed, even on steep gradients. They offer just the right amount of lateral flex to give the bike a certain versatility, while blending perfectly with the aerodynamic lines of the frame. On the flat at high speed, the efficiency of the whole setup is very noticeable, and we were pleasantly surprised by the stability of the bike, even with a strong crosswind and 50 mm rims. The weight of the machine, its geometry and the fact that the cockpit is relatively long (with weight over the front wheel) gave very good control in this situation, despite the rider’s light weight. In short, in this particular case the Dura-Ace C50 wheels soften the Orca Aero and give it versatility.

The sensations change somewhat with the Tarmac SL7, which is 1.5 kg lighter and has a different geometry. The top tube is longer here than on the Orbea, and the stem is shorter. For the same distance between the saddle and the brake levers or the bottom of the handlebar, a little less weight sits on the front wheel. The shape of the tubes is also less extreme, and the rim profile is less integrated into the overall profile of the bike. With this setup, the Dura-Ace C50s keep their liveliness and sharpness, and they even seem to weigh much less than they do. Accelerations remain very crisp. The wheels are stiff, but not excessively harsh or brittle when you are overly optimistic about your gear choice. But on this bike they feel a little less smooth than on the Orbea. On sprints launched at close to 60 km/h, they hold together when you put maximum watts through the pedals. Here they follow the behavior of the frame perfectly, and come across as very high-performance wheels while avoiding being too exclusive, just like the SL7 itself. On the other hand, the Dura-Ace C50 wheels make the bike more sensitive to crosswinds than the Orbea. The Tarmac is already a bit twitchy up front, with very quick steering, and here a sidewind can quickly make a ride demanding with such a profile. In this particular case, and without being extreme, the Dura-Ace C50s tend to make the Tarmac’s behavior a little more pronounced.

That said, our opinion of the Dura-Ace C50 wheels is very positive, first for the good compromise they offer between weight and stiffness, and second because reliability appears to be fully there. After 7,000 km on the Tarmac, nothing has changed. There is no runout on the rims, and the bearings spin as they did on day one. Spoke tension seems identical to that of a brand-new pair of wheels. The freehub’s engagement when resuming pedaling, slightly quicker than average, is noticeable at first, then quickly becomes transparent, so quickly do you get used to this high level of performance. Beyond the crosswind sensitivity inherent to this rim height (more or less noticeable depending on the frame they are paired with), the Dura-Ace C50s finally stand out for a certain form of absolute versatility. They belong to the category of high-performance wheels, but their behavior is not caricatured. Above all, the 50 mm rim height never seemed to us to be a disadvantage when accelerating, on steep climbs, or even in the mountains. With good tires (tubeless or with inner tubes), the Dura-Ace C50s can be used all year round, regardless of the amount of climbing. That is their very first asset.

In the C60 version, the Dura-Ace are expected to be even stiffer and more exclusive, with reinforced spoke lacing. They are therefore best reserved for heavier riders, sprinters or big-mileage riders. In the C36, with a lower rim height, they are without doubt less sensitive to crosswinds. Given the overall quality of this new model’s build, this may be the version to favor for cyclosportive riders or lighter riders.

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