Reynolds Aero 58 clincher wheels

Despite a couple of niggles, the Reynolds Aero 58s are excellent wheels: fast, stiff and stable in sidewinds.

New from Reynolds for 2013 is the Aero wheel range, featuring new rim shapes and other technology designed to cheat the wind and increase your speed. The range is clincher only, and comprises three rim depths: 72mm, 90mm and the 58mm model tested here, which is likely to appeal to the road racing crowd as well as triathletes and time triallists.

New technology

The biggest news is the development of a new rim cross section which Reynolds term Dispersive Effect Termination, or DET for short. Here's the man behind the idea, Paul Lew to give you a quick overview of the benefits:

In keeping with the trend for wider wheels pioneered by the likes of HED and Zipp, the Aero 58 (and indeed all models in the range) feature a brake track width of 26.2mm. To put this into perspective, the Zipp 404 Firecrests measure in at 24.7mm, though they do balloon out to 26.5mm below the brake track.

All aero benefits aside, this width could cause some issues with clearance, especially in older frames designed before the advent of wider wheels - I struggled to get them to clear my brake pads on my time trial bike for example. Try before you buy is most definitely recommended.

The wide brake track is where the similarities to the Firecrest and other wide rim shapes end however, as the Aeros taper down to a sharp point at the trailing edge, contrasting with the blunt trailing edge employed by nearly all the competitors.

Despite the increase in overall rim width, the width between bead hooks is still pretty conventional at around 15mm. As a result, 23mm tires are the maximum recommended for aerodynamics as a wider tyre will tend to balloon outwards, adversely affecting the transition between tyre and rim.

Stepping up

The reason for the narrow internal width is that the rim steps outwards from the leading edge to the brake track, creating a little ledge which runs around the whole wheel. The purpose of this is to create a zone of low pressure to help re-attach the air to the rim surface, after it has been disturbed by the tyre. This feature is unique to the 58mm and 72mm versions, as the 90mm version actually features a step on the inside surface - the idea being that air behaves differently as it passes over rims of different depths, so each rim shape must be unique.

For those geeks out there (myself included) Reynolds have published a white paper going through the design process and testing of the DET technology. This is available on the Reynolds website [currently down or we’d link to it - Ed]. In summary, there's been a lot of thought and effort gone into the aerodynamics of these wheels - even the valve hole is aero optimised.

As well as aero performance, the other key consideration with full carbon clinchers is their braking performance. The Aero range employes Reynolds' CTg (Cryogenic Glass Transition) brake track which is a specific carbon laminate claimed to improve heat dissipation, thereby providing a more consistent braking performance even under extreme use. The wheels come with Reynolds' Cryo Blue brake pads, designed specifically for the CTg surface. Use of any other brake pads will invalidate your warranty.

One the road: speed increase & cross-wind stability

Out on the roads, the Aero 58s are discernibly fast and easily give you a 2km/h speed increase over a high profile wheel such as a Mavic Ksyrium (my normal training wheels). As a power meter user, I was consistently impressed with the average speeds I was able to achieve on rides where my power wasn't anything special. Comparing the Aero 58s to other wheels of similar depth (in terms of pure straight line speed) would require proper wind tunnel testing as the differences are too subtle to fully appreciate while out riding. Reynolds claim their wheels to be the fastest but then they would, wouldn't they?

What was most surprising was the 58s stability in crosswinds. Recent weather has been very windy and provided the perfect testing grounds for wheels claiming to be the best handling on the market. Consistent, high cross winds proved no problem whatsoever, it was only in really gusty conditions, such as when passing a gap in a hedgerow, that the 58s could be unsettled. Such was their predictability that I had no issue taking them out in 20+mph winds a mere 10 days after breaking my collarbone. I was able to test the wheels back to back with a set of Enve Smart 3.4s and felt that the Aero 58s were easier to handle despite being nearly 20mm deeper on the front wheel.

Stopping

Braking performance in the dry is very good, with a smoothly progressive feel and plenty of top end power. Coming directly off Mavic's market leading Exalith braking surface onto these 58s, the difference in power and modulation was only small.

However, despite the revised Cryo blue pad design with large water shedding slots, the Aero 58s still exhibit the delay between applying the brakes and actually slowing down that affects most rim brakes. When the power does turn on, it is quite grabby so you really have to be paying attention. By no means are the 58s bad in the wet compared to other carbon wheels, but there's still some way to go before they are as predictable as alloy wheels.

At 1601 grams (measured, without skewers), the Aero 58s aren't going to set weightweenies' hearts a-flutter, but this is still pretty good for a clincher wheel of this depth. More importantly, the wheels ride a lot lighter than they are, being easy to get up to speed when sprinting out of corners.

Deep section carbon wheels often suffer from brake rub due to an imbalance between the rim stiffness and the spoke stiffness. The push towards improved aerodynamics has led to reduced spoke counts which simply can't handle to stiffness of the deep section, carbon rims. You often see the Tour sprinters using custom wheels with more spokes for this very reason. I couldn't tempt the Aero 58s into any sort of brake rub, which speaks to how balanced the wheels are. It's obvious that plenty of thought has gone into making this the ultimate road racing wheel.

Niggles

From a performance point of view, the Aero 58s are right up there with the best wheels in the market. However, when considering dropping over 2 grand on a set of hoops, you want every detail to be perfect. I had a couple of niggles with the Reynolds Aero 58s which put a small damper on an otherwise flawless performance.

Firstly, the wheels tend fill up with water when riding in the wet. The internal nipple design - another bugbear of mine but not such an issue on clinchers - means that there are plenty of entry points for water around the locations at which the spokes enter the rim. You have to take the tyre off to drain the rim which is a pain.

A couple of handy little bungs are included with the wheels, which prevent the valve from rattling around and seal the valve hole from water, but these both fell off after a couple of rides. You'd have thought this would have been identified in the road testing stage but obviously the roads in Utah are a lot smoother than in the west country.

And finally, why do wheel companies insist on supplying wheels with crappy external cam skewers that die after a few rides in the wet? Yes, they are light, but skewers are one place I'd prioritise function and safety over shaving a couple of grams. My advice: stick a couple of Shimano skewers on them and be done with it.

Foibles aside, the Aero 58s have muscled their way to the top of the mid-depth carbon clincher pile.

Verdict

Fast, quick-accelerating and superbly stable in crosswinds, the Aero 58s set the new benchmark in carbon clincher performance.