Hunt is launching a new range of Carbon Aerodynamicist rim brake wheels that feature aero technology derived from its Limitless disc brake wheels introduced last year.
The 52mm, 62mm and 82mm-deep profiles have been developed in-house by Hunt's product engineering manager Luisa Grappone.
"We've been able to take the principles found during the Limitless research project [widening sidewall profiles below the tyre interface to improve performance and stability across multiple yaw angles], and apply these to rims that make the absolute most of the space offered inside a conventional calliper brake," says Hunt.
"An optimum aerodynamic benefit for a drop-bar bike is yielded from widening rim profiles. The reason for this is that it allows for a far more 'blunted' spoke bed area, which (depending on which part of the wheel you're looking at) is both the leading and trailing edge.
"The benefits of blunted spoke bed areas revolve primarily around the predictable airflow, with the wind 'hugging' the rim as it passes across it (as opposed to older style V-shaped rims, which would create turbulence in the form of stalls). The wider profile ensures the flow stays attached to the surface as long as possible before the point of separation, which is key as yaw angles increase."
A rim brake rim provides very different challenges from a disc brake rim because of the width constraints of the calliper, and a different fork design. The 48 Limitless Aero Disc has a profile that measures 34.5mm at its widest point while the maximum width of the new Carbon Aerodynamicist rim brake wheels varies from 28.1mm to 29.5mm.
The tubeless ready rims have an external width of 27mm at the brake track and an internal width of 19mm (62mm and 82mm-deep models) or 19.5mm (52mm-deep model). They're hooked for compatibility with both tubeless and non-tubeless tyres, and the aero performance is optimised for 25-28mm tyre width.
Hunt says that the 82mm-deep Carbon Aerodynamicist wheelset is faster than tested competitors
(the Zipp 808 NSW is the same depth as the Hunt, the Enve SES 7.8 and DT Swiss ARC 1400 Dicut 80 are both a little shallower) when fitted with a Continental GP 5000 23mm tyre, while the 52mm and 62mm models are both "incredibly competitive".
Hunt's results say that its 52mm-deep wheelset proved more aerodynamically efficient than the Zipp 303 NSW (45mm deep) and the DT Swiss ARC 1400 Dicut 48 (48mm deep), but less than the Roval CL 50 (50mm deep) and the Enve 4.5 SES (48mm deep front, 56mm deep rear) when fitted with a Continental GP 5000 tyre in either a 23mm or 25mm width.
Its results say that the 62mm-deep Hunt wheelset proved more efficient than the Zipp 404 NSW (58mm deep) and DT Swiss ARC 1400 Dicut 62 (62mm deep) but less efficient than the Roval CLX 64 (64mm deep) and the Enve 5.6 SES (54mm deep front, 63mm deep rear).
Hunt did its wind tunnel testing at 45km/h (28mph) covering yaw angles of +20° to -20°. The full testing methods, results and interpretation (including details on the wind averaged drag calculation) are set out in a white paper that introduces the Carbon Aerodynamicist range.
All of the wheels are made from Toray T700/T800 carbon-fibre with unidirectional sidewalls and 3K weave bed and spoke areas. Griptec basalt ceramic fibre brake tracks are designed to offer excellent braking and durability.
The wheels use Hunt Race Season Sprint hubs with Ceramic Speed bearings. The rear hub engages in 7.5° when you start to pedal. A steel spline insert protects the cassette body from the digging in of sprockets.
Hunt 52 Carbon Aerodynamicist wheelset 1,518g £1,189
Hunt 62 Carbon Aerodynamicist wheelset 1,575g £1,249
Hunt 82 Carbon Aerodynamicist wheelset 1,738g £1,329
You can mix and match front and rear wheels of different depths.
Get more info over at www.huntbikewheels.com
Mat has been in cycling media since 1996, on titles including BikeRadar, Total Bike, Total Mountain Bike, What Mountain Bike and Mountain Biking UK, and he has been editor of 220 Triathlon and Cycling Plus. Mat has been road.cc technical editor for over a decade, testing bikes, fettling the latest kit, and trying out the most up-to-the-minute clothing. We send him off around the world to get all the news from launches and shows too. He has won his category in Ironman UK 70.3 and finished on the podium in both marathons he has run. Mat is a Cambridge graduate who did a post-grad in magazine journalism, and he is a winner of the Cycling Media Award for Specialist Online Writer. Now pushing 50, he's riding road and gravel bikes most days for fun and fitness rather than training for competitions.