Mercury isn’t limiting carbon rim development to trail bikes, they’ve also been working with aero-guru Paul Lew on an all-new A-series of aerodynamic carbon road wheels as well. While at first glance they aren’t as visually striking as those flat-topped, mystery Fiber-X carbon enduro wheels, they do use a decidedly unconventional chopped top Kamm Tail rim profile to slice the wind.
Mercury A-Series, Kamm Tail aero carbon road wheels
Mercury Cycling says they worked with aerodynamics specialist Paul Lew to develop a fresh approach for the new their A-series wheels. First conceived in CFD, the wheels use a shape that Mercury is calling Kamm Tail 10 (#patentpending).
The idea just like you see in aero frame profiles is that by chopping off the tail of an aerofoil shape you get the effective drag reduction performance of the longer shape lighter with less material, and with less impact from side wind conditions. On the wheel the effect looks even better as the chopped Kamm tail works similarly in the opposite direction, just like most modern blunt-nosed aero rim profiles. It even seems like the controlled air flow off the leading rim edge creates more of the ‘sailing effect’ we’ve seen in some aero wheels, knocking drag dow to zero (even providing some forward push) at strong quartering wind angles.
This first new A5 aero wheel has a real depth of 55mm that is said to perform with the same perceived effect as an effective 67mm depth rim. Complete wheelset weight isn’t superlight at a claimed 1754g, but here the aero performance is key, and Mercury says they measurably outperform benchmark aero wheels like the Zipp 404 Firecrest & Reynolds 58 in almost every wind condition.
The new A-Series wheels are set to be officially debuted in Taipei this coming week, and will include 36mm, 55mm & 77mm depth rim options (equating to effective 50mm, 67mm & 92mm depths, respectively.) All of the wheels will offer rim & disc brake variants with hi-temp carbon resins, and use straight-pull Mercury Tempest hubs with 2:1 lacing for balanced tension.
Like the new mountain bike wheels, we should have the full aero details within a week. Keep an eye out…