Joining VeloClub not only supports the work we do, there are some fantastic benefits:
by Dave Rome
January 9, 2020
Photography by Hunt Bike Wheels
Aero testing, or at least the data, can so easily be tricked and tweaked to provide the desired outcome for one’s brand. And so my attention was gained when Hunt shared a press release that openly admitted its newest rim-brake wheels were competitively fast, but not the outright fastest on the market.
Hunt’s latest trio of new carbon aero rim-brake wheelsets – an extension of the current Limitless range – are certainly about as fast as the biggest-name wheels, and they do so at an impressive price point. But the most interesting story here is the data shared within the company’s latest white paper that shows how the likes of Roval, Zipp, DT Swiss, and Enve currently compare in the wind.
I cover the basics of these new Hunt rim brake wheels below, but first, let’s look at the data from the British company’s latest white paper.
For this, Hunt returned to the GST wind tunnel in Immenstaad, Germany to test and compare its new Limitless rim brake wheels against a number of benchmark competitors. The testing was done with the wheels mounted to a Canyon Aeroad CF SLX and with the same Continental GP5000 tyres, tested in 23, 25, and 28c variants used across all wheels.
Various yaw angles were tested, and the weighting of the data was done according to the so-called ponderation law, which was proposed by Mavic and is perhaps the closest thing we currently have to an industry standard for evaluating aerodynamic data. However, Hunt’s testing did omit the most extreme 22.5- and 25-degree yaw angles, simply because its chosen wind tunnel’s turntable doesn’t go past 20 degrees yaw.
All wheels were tested in motion, at a rolling speed of 45 km/h. Such a speed is generally quite typical for wind tunnel tests of cycling products, even if it’s on the high side of what many of us mere mortals are able to maintain.
This chart shows how Hunt’s new 52mm-deep wheel stacks up against the test competition. A lower number in the centre column is better.
The end results point to Roval’s CL50 and CLX64 wheels being the outright fastest for wheels of 50 and 60 mm depths; Enve’s 4.5 SES and 5.6 SES wheels came second in each category respectively. Hunt has its new 52CA and 62CA wheels ranked third behind Roval and Enve, but ahead of Zipp and DT Swiss.
Hunt versus the 60 mm depth competition.
One area of this testing that brings out my cynicism is the lack of comparative data for the tested 28c tyres. Hunt’s new wheels are optimised with 25c tyres in mind, and Hunt data points to there being a small increase in drag with each tyre size increase. However, a few brands, such as Zipp, have previously claimed that some of their wheels offer the lowest drag when used with 28c tyres, and so it is possible that certain configurations not shared could lead to more favourable results for certain brands.
For those keen on really deep wheels, the new Hunt 82CA (82 mm depth), combined with a 23c tyre, is shown to be the fastest setup tested, beating the Zipp 808 NSW and Enve 7.8 SES. Although what’s more interesting is just how little drag is reduced with such a deep wheel when compared to the impressively quick (and shallower) Roval CLX 64.
A drag comparison between Hunt’s three new wheels.
Hunt’s new rim brake aero wheels are an extension on the Limitless range, previously only available for disc brakes. The Limitless range comprises Hunt’s first fully conceptualised-, designed- and engineered-in-house wheels, steered by Hunt’s engineering and product manager Luisa Grappone. Grappone joined Hunt some two years ago having worked on projects with Boeing before turning to the cycling industry to become a senior product engineer at 3T and then more recently Campagnolo.
First released last year (and recalled soon after), Hunt’s Limitless 48 Aero was a disc-only design where the 34 mm external width was only made possible due to the lack of clearance constraints offered by the use of disc brakes over traditional rim brakes. Of course, those space constraints remain present on current rim brake bikes and so Hunt couldn’t simply add brake tracks to its ultra-wide flagship aero wheel.
The new Carbon Aerodynamicist range consists of three depth options.
As a result, the company’s new Carbon Aerodynamicist range, consisting of the 52, 62 and 82, offers a U-shaped rim profile that’s not too far removed from its competition. Each depth rim offers an approximate external width of 27 mm, and an internal 19 mm width.
The braking surface is a “Griptec basalt ceramic fibre” which, Hunt claims, offers excellent braking performance and durability.
The specific rim shapes and widths vary slightly between depths.
Hunt, a consumer-direct wheel company, supposedly set about the design knowing it wanted to stay with a hooked rim bed for tubeless and clincher compatibility. The rim widths are optimised for 25c tyres, however, Hunt claim 23 and 28c tyres are fine for use, too. The rims have been designed to the pending ETRTO road tubeless standard.
All three rim depths are laced with Pillar’s Wing 20 straight-pull aero spokes and to Hunt’s Race Season Sprint hubs. These hubs offer a competitively quick 7.5-degrees of engagement from three stepped pawls. The freehub body is given a steel insert to prevent cassette teeth from digging into the aluminium splines.
Like the Limitless 48 Aero Disc wheels, all Carbon Aerodynamicist wheels will come fully fitted with typically high-priced CeramicSpeed bearings as stock.
The three depth wheels will be available as pairs or individually for mixing-and-matching depths (a shallower depth for the front wheel is a popular choice). Hunt quote the 52CA, 62CA and 82CA to weigh 1,518, 1,575 and 1,738 grams respectively.
And while Hunt may not be the very fastest in its popular 50 and 60 mm depths, it’s hard to argue with the asking price. For example, the 52CA wheelset is priced at US$1,549 / £1,182 / AU$2,259 including global shipping (potential import taxes and duties not included). The wheels are expected to be in stock by late March.