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Mercury A5 aero carbon road wheels get Paul Lew designed Kamm Tail rims

Mercury A-Series carbon road wheels Kamm Tail 10 aerodynamic road bike wheels, designed by Paul Lew aero guru A5
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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).

Mercury A-Series carbon road wheels Kamm Tail 10 aerodynamic road bike wheels, designed by Paul Lew aero guru A5

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.

Mercury A-Series carbon road wheels Kamm Tail 10 aerodynamic road bike wheels, designed by Paul Lew aero guru A5

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.

Mercury A-Series carbon road wheels Kamm Tail 10 aerodynamic road bike wheels, designed by Paul Lew aero guru A5

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…

MercuryCycling.com

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Schmoe
Schmoe
3 years ago

I call BS. The last time I knew, Lew only used 2D sectional analysis on from leading section of the wheel. He didn’t take into account the full wheel system, and his programming was less than ideal. The CFD graph in the article is reminiscent of that same work. Lew was more salesman than engineer. Hopefully Mercury didn’t spend too much consulting with him.

Hexsense
Hexsense
3 years ago

Kamm Tail works great by chopping off the TAIL of aero foil.
Spoke edge is the tail only on less than half of the circle, it is leading edge for another half.

Be skeptical, until they proven good by third party test.

AK_Ben
AK_Ben
3 years ago

A similar Kamm-tail rim profile wheel from Zeal reviewed by CyclingTips.com received pretty low marks, especially surprisingly on crosswind performance.
http://www.cyclingtips.com/2019/03/zeal-camerig-44-carbon-clincher-review/

Dex
Dex
3 years ago

I’m sure that Zipp and Reynolds have nothing to worry about regarding wheel performance. All these wind graphs are generated to increase sales to gullible dentists and lawyers who want to get expensive speed products so they can say their wheels are faster when they go off the front while the rest of the group is still in warm up mode for Tuesday night worlds. They get an extra 3 seconds of glory before they get summarily dropped because they would rather buy speed than do a few extra intervals.

Mr Pink
Mr Pink
3 years ago

Lost me at “Paul Lew”

Greg
Greg
3 years ago
Reply to  Mr Pink

(deleted)

Mick
Mick
3 years ago
Reply to  Mr Pink

Ditto…

gmagee
3 years ago

Wheel drag as it actually affects vehicle motion is highly concentrated at the top of the wheel. The CFD guys don’t know this, or don’t want you to know. Embarrassing. So measuring drag on the wheel as force at the axle, is only a relative measure, not a real world comparison. One needs to measure drag reduction at the upper part of the wheel, as this is where the action really is. That is why actually shielding the upper part of the wheel from headwinds is extremely effective, especially against ground headwinds.

The potential benefit of the chopped tail rim profile is improved crosswind transparency, and some shielding of the nipples in strict headwind conditions. Better is to use a traditional shallow rim with swiveling spoke tailfins over round spokes, now legal for Ironman. The fins auto adjust to the crosswind angle.

Tubeofcaulk
Tubeofcaulk
3 years ago
Reply to  gmagee

dude, not the place to promote your product @gmagee. Don’t hijack the thread for your own gain. It’s unbecoming.

Gillis
Gillis
3 years ago
Reply to  Tubeofcaulk

I wouldn’t say he’s promoting anything, not directly. He doesn’t specify a product. He doesn’t link to any website. The hotlink on his name (which isn’t a brand name or anything) here says who he is, sort of, but still doesn’t take you to website. He argues his point civilly.

Robin
Robin
3 years ago
Reply to  Gillis

It only seems like he’s not promoting himself and his product because this time, unlike the multitude of other times, he forgot to mention his product or provide a link to it.

blahblahblah
blahblahblah
3 years ago

why all the hate im sure these wheels will save you 1.2 seconds in a 200K (yes that is 200) time trial, provided the wind is at 31.453729 degrees

Bill Bob
Bill Bob
3 years ago

So at 90° at 50km/h 1110g drag more for Zipp, which would equal 111 watts? Aha.

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