In the late 1990s, Rolf Prima wheels were getting spec’d on a great many Trek road bikes, most of them, at least according to my memory. Their approach of pairing spokes at the rim, rather than alternating the drilling, made the wheels arguably the easiest low-spoke-count wheels to true, but it did come with one liability at the time. The rims cracked nearly as often as eggs.
A few things have changed since then. Rolf Prima ended their relationship with Trek and began hand-building all their wheels in their Eugene, Oregon, facility. They also revised the design of their rims so that the rim failures became, like their relationship with Trek, a thing of the past. Another thing of the past—Rolf Dietrich himself. He retired and sold his shares of the company to his partner Brian Roddy who continues to run the company today.
Since then, the company has introduced carbon clinchers and has brought aluminum rim production in-house. While the carbon clincher rim is produced overseas, all the engineering is performed in-house, so these are not open-mold designs with a fancy sticker. The company went to White Industries to produce all of their hubs, which brings me to another of Rolf Dietrich’s ideas from the 1990s, the patented Differential Flange Diameter.
Differential Flange Diameter is, in short, a high-low flange design, with the high-diameter flange used on the non-drive side of the hub. According to their testing, the DFD results in more torque being delivered to the non-drive side of the hub, which reduces stress on the hub, the spokes and even the rim, making for a longer-lasting wheel. There’s more to their top-of-the-line TdF 5.5 hubs than the flange, of course. The titanium freehub body uses a three-pawl engagement, sits on top of ceramic bearings and is available in Shimano or Campagnolo versions.
I first rode the Ares 4s at the Oregon Gran Fondo this summer, which was also when I got to visit Rolf Prima’s home in Eugene. They were on a Co-Motion Nor’Wester and the aero advantage of the wheels made it a particularly quick-feeling steel bike. After getting home, they sent me a set to ride for a full review and I’ve had a chance to ride them with two different sets of tires and on two different bikes.
The Ares 4 uses a 42mm-deep and 17mm-wide (internal width) rim with a rounded spoke bed, making it comparable to Zipp’s 303 wheel set. My personal preference is for wheels in this class because they offer an unmistakable improvement in aerodynamic performance, are shallow enough not to provide a strong crosswind much purchase and remain light enough that acceleration isn’t compromised.
My wheel set weighed in at 1465 grams; that’s 635g for the front and 830g for the rear, and while that’s exactly 100g more than Rolf Prima claims, it’s worth noting that weight is still 100g less than the 303s and some other competing wheels. How they do that is no mystery. The Ares 4 uses 16 spokes, both front and rear. That was the promise of the paired spokes; you could use fewer spokes, so long as they were paired. Speaking of spokes, Rolf Prima uses what has become the gold standard in bladed spokes: the Sapim CX-Ray.
Such a low spoke count can result in a wheel that deflects noticeably in standing efforts, but I never had an issue with this. Normally, any time I ride a front wheel with 20 or fewer spokes, I can detect some flex, usually when standing on a climb, but I didn’t experience that with these wheels. The 85mm-wide flange spacing might be partly responsible.
I’ve ridden these wheels on a few of the canyons around here and can report that the braking performance on these is preferable to some other carbon clinchers I’ve tried. Rather than just making some white noise under attempts at light braking, these wheels do slow and respond in a nicely linear fashion. It made controlling speed in technical turns nicely predictable.
After having spent some time on a more old-school deep-V design recently, moving to a rounded spoke bed, double leading-edge wheel was, dare I say, a relief. There’s no doubt in my mind that at least in the case of the wheels I’ve ridden, these designs are much faster and handle noticeably better in crosswinds. I’ve talked with a couple of engineers lately who have both said that in their efforts to find out just what the average rider is sensitive to, an improvement in aerodynamics is the only change most will get right. That’s right, an improvement in aerodynamics is easier to pick out than rim material or weight.
What I can say is that after switching between the Ares 4s and the Zipp 303s, I found the 303s to be better in crosswinds. The 303s seemed to be faster as well, but because of differences in tires, conditions and my legs from one day to the next, I’m not going to swear on that one.
At $2399, the Ares 4 is a good $400 less than the 303s and just $200 more than Specialized’s Roval Rapide CLX 40, another comparable wheel (in rim depth and width). It’s a great price for a very high performance wheel, especially when you consider that number includes skewers, brake pads, rim strips, valve extenders and a padded wheel bag. That said, Rolf Prima will also be offering the Ares 4 with its less-expensive American-designed but overseas-sourced hubs. The more budget-minded hubs won’t roll as well and may not last as long as the White Industries hubs, but that down spec will give Rolf Prima a chance to offer a high performance carbon clincher for only $1800. Watch out.