How Much Faster Are Aero Wheels?

How Much Faster Are Aero Wheels?

Aero wheels don’t just look cool but we’re
also told that they make you faster too. But how much faster? We wanted to do an
experiment to see typically how much more speed an aero wheel can give you.
So to do that we came down here to Herne Hill velodrome in south London
where we are going to put three different sets of wheels to the test. So
the first set of wheels we have is a pair of Mavic Ksyrium R-SYS SLR clinchers.
We’ve picked these because they represent the typical box section
clincher wheel that you get on a normal road bike and most road bikes are
equipped with a shallow wheel like this. Second set of wheels were going to
test are a pair of Enve Smart 4.5 which have a 40mm front rim and a 50mm back rim.
Now we picked those because that’s a very classic typical current
professional set up. For the final set of wheels we’ve got a HED GT3 trispoke
front wheel and a Lighweight Autobahn Disc which is incredibly bling in about
£2500. Now we’ve picked this because it’s said to be the
ultimate time trial setup and it’s been used by the likes of Alberto Contador
amongst others. For our experiment Dr. Hutch’s going to be doing the riding.
For those unfamiliar with Dr. Hutch he’s sort of a pound shop Stig. And he’s gonna
be riding each set of wheels for 10 minutes at 200 watts and 10 minutes at
300 watts around the velodrome. We’re doing this because we thought 200 Watts
was maybe typical of a decent club rider or a sportive rider
and 300 watts is maybe more than a number a time trialist or a racer at
hit. So we’ll see what the benefit might be if you’re riding quickly and even
then what the benefit might be if you’re maybe not going quite at a race pace. For
consistency Hutch is going to begin every run from a rolling start and we’re
using Powertap P1 pedals for power measurement and we’re also using
Challenge Record tyres with latex inner tubes on all the wheels. I’ll be riding
the same Merida Reacto team bike and all the tests and keeping a consistent
position on the drops and all the tests we do to try and keep a level playing
field. Before we get on to the results, Oliver
is a proper scientist and would like to issue a quick disclaimer. Yes, so we’re
aware this is not the most accurate test in the world but for all the wind tunnel
data that exists around bikes and wheels no one actually rides their bike in a
wind tunnel. I do. Apart from Hutch. So based on that we want to see what
actually happens when you ride these things outside so there is value in that
and Herne Hill is about as much as a controlled environment as you can get
outside. So, Oliver, what were the results? The Mavics that you rode first at 200
watts you travelled the distance of 5120m,
an average speed of 30.7 km/h and at 300 watts you traveled 6070m at an average speed of 36.4km/h. So quite a
bit faster faster – yeah, yeah. So then on to the Enves you travelled at 200 watts
5460m at an average speed of 32.7km/h. So that’s two and a bit kilometres an hour faster? A two kilometers an hour faster. And at 300 watts you travelled 6442m at an average speed of 38.6km/h. So again roughly two kilometres an hour
faster. So for the super-duper TT set up at 200 watts you travelled 5520m, an average speed 33.12km/h.
And at 300 watts… Little quicker… Yeah, a little bit quicker. And at
300 watts you traveled 6600m at 39.6km/h. So that’s basically
25 miles an hour. And that’s quicker again. Yeah, so just a little bit
quicker than the Enves but I think the main thing is the difference between the
Enves and the time trial wheels were quite small. So the big
step up is from the kind of box section simple shallow rim wheels up to the
modern rim wheels. Yeah and even at 200 watts you’re traveling 2km/h faster on a 40/50mm rim.
And it’s actually quite windy here today so you know with
the kind of your angles and the rest of it actually deep rims probably start
to perform even better. But it does go to show that I mean even if you’re just
averaging 200 watts over the course of a 100 miles sportive that could really
add up to a massive. If you’re spending 5 or 6 hours out it’s going to be most of another hour’s work. So if saving two
kilometres an hour is important to you then investing in some aero wheels is well
worth considering. How much you care about two kilometres an hour Oliver? I’ve
killed for two kilometres an hour.

About the Author: Michael Flood


  1. I think this is legit. Did a few similar 1 hour tests on my climbing wheels and deep section. Difference was 1.5 to 2kph difference with 250 watts avg

  2. Comparing the ENVE 4.5s to the Mavic R-Sys SLR at 200 watts, the tests showed that the average speed was 32.7 kph for the ENVE compared to 30.7kph for the Mavics. If you extrapolate that out to 40 kilometers, it seems to show that the ENVE wheels save you almost a full 5 minutes. If my math is right, that's a big claim. Are the Mavic wheels that bad or the ENVE's that good?

  3. To be able to go 2kph faster with the shallow wheels you probably would need about 30 35 watts more. The Enve wheelset is around 2800 euros. So its kinda like buying a watt for 80 90 euros….

  4. Another interesting real world test would be to compare a relatively good aero alloy rim, like the November FSW3, which compares favorably to a ZIP 303 in the wind tunnel, to other deeper rims, like the enve 4.5 / Zipp 404. I would think given the wind tunnel tests that a good alloy rim wouldn't give up much to its deeper counterparts. I would bet in a 40 kilometer run, a good alloy wheel would be within 15 to 30 seconds of some of the best carbon wheels.

  5. This is a very big difference! I did upgrade my wheels for 50 mm Easton wheels on my road bike, can't say for sure that I saw a difference as I couldn't compared to my old times with the non aero setup, but I find it very satisfying when I overtake other riders at 50 km/h on a flat section.
    But still, when it comes to upgrading your aerodynamics, you should make sure the cheap parts are already focused on aero before spending much$$$$ for aero wheels (helmet, shoes, clothes, body hair, gear cables, baggies, rear spoiler…)

  6. what are the weights of those wheels?
    of course lighter wheels will be faster
    this test has to be made with wheels that weight the same


    2km/h is huge. But did you try to recast the aero gains into Watt savings? I quickly used Aeroweenie calculator: I left all the default values, except I have changed the CdA to 0.45 (in order to reproduce your 200 Watts for 30.7kmh case, but it should not matter that much, since we use SAME CdA for 'bike A' and 'bike B'). So, having same CdA, I put v1 = 30.7kmh, and v2 = 32.7kmh, press the magic 'Do Physics' button. Results are: ~200W @ 30.7kmh agains ~238W @ 32.7kmh. dP ~= 38W (!!!)… THIRTY-EIGHT WATTS! According to ALL articles, graphs, ads, etc. that I've seen, 38W sounds just toooo much for box-rim VS 40-50mm aero!.. I mean, I would like to believe that my aero wheels give me that kinda boost alread at 200W, but… is it legit?

  8. I always love to see these real life tests. Much better then to see a bunch of wind tunnel data. Great work guys. 🙂

  9. I can attest to this. I am roughly 1 to 2mph faster on my carbon rim Zipp 808s than on my PowerTap wheels. Is it because they're deep dish? Or is it because Zipp's bearings are far superior? Probably a bit of both.

  10. Good test. Nice to see real world stuff like we do, outside of the wind tunnel, which is such a compromised environment as to be of little use for practical results.
    And also goes to show how testing between wheels OF THE SAME DEPTH, in a wind tunnel is pretty pointless as they will all be within operational error of each other, despite what the adverts say….

  11. I think a better number then say just saying 300watts is putting up the watts per kg as 300watts for a skinny 60kg guy may be 5 watts per kg whille a heavier say 75kg rider is only doing 4kg. but other wise nice video

  12. The european's are a strange bunch. They weigh themselves in stones and count their money in pounds. I do like the metric system though :))

  13. It's interesting to see the difference, but it's a bit of a joke to choose arguably the most unaero modern wheels on Earth as the comparison. As someone said below, the R-Sys wheels came last in the aero section of The Great Wheel Test a few years ago.
    Ok, that was in 2008 but, as far as I can find out, they've still got 4mm-thick, round, air-catching spokes. R-Sys wheels might be light, but that are total parachutes. 🙂
    Incidentally, the Great Wheel Test totally killed all Ksyriums, since we saw how draggy they are.
    Most tests like this use old, very unaero wheels, such as Open Pros with 32 spokes — I assume to exaggerate the difference — but I hardly know anyone who rides wheels like that. I wish they'd compare the aero wheels to "real" alu wheels that people actually use these days, such as Eurus, Fulcrums, shallow Shimanos, or Bontragers, etc, etc.
    In other words, the test is an unrealistic comparison, because we can buy passably aero alu wheels for HEAPS less cash.

  14. I think the biggest difference is looking at your bike with cheap shallow stock wheels and looking at your bike with deep sections (alloy or carbon) and the mental aspect of "im riding wheels that cost more than the bike itself" is a big difference

  15. The problem with this test is that the Mavic R-Sys isn't a typical box-section wheel at all. In fact, it might be one of the least aerodynamic wheels you can buy. It has enormous tubular spokes and nipples, which don't taper into bladed until a few centimeters from the rim, and I'm not sure the profile of the blading is sufficient either to match a CX-Ray or even a traditional round spoke. Of course, that thick top section is where relative velocity is twice that of the rider on the top of the wheel. There's a company that tested 50+ wheels in 2008 and they found that the 2007 R-Sys (spokes haven't changed) had the worst aerodynamics of all, by far.

  16. THANKYOU for doing tests at low wattage for us casual cyclists who can’t hold 45kph 🙂
    Please incorporate more lower wattage test data in future testing. We low powered cyclists want this info too.

  17. Might have tried to standardize it by using different depth wheels from the same manufacturer (or even from the same range within that manufacturer) to make it a more apples-to-apples comparison, and to mitigate difference in weight from different manufacturers for the same depth wheels.

  18. how much of the time saved is due to the weight loss of wheels rather than how aero they are? for a more accurate test, all 3 bike setups need to weigh the same

  19. Please make the same test in a bunch ride setup. Are aero wheels faster in a group sportive i want to know. I think no difference as long as i hug rear wheels infront of me combined with uphill advantages. Take it to the test!!!

  20. I only have a set of Shimano r501 wheels. I've covered my rear. Now I'm thinking to buy a front Campagnolo Scirocco wheel. I hope it is enough.

  21. I like these real world tests. I like that the other guy rides his bike in a wind tunnel

  22. This is the kind of test that should be done…that wind tunnel stuff leaves out the component of external conditions.

  23. I have friend that has 15 pound Scandium bike for 1980's, Rims are very old school, light weight but almost squared off. Please redo test with those type of rims. Post photo all 4 types and results of all 4 types on one page is possible. so you see and compare is one or two screen shots – paused for those of us that like to review data. Thanks. Love your testing. real life. Come to Arizona and do fund raiser ride _ Tour de Tucson. Must pick up race packet with photo ID day before race. Ride on.

  24. Would never buy anything from Ribble cycles simply as a result of the relentless tedious onslaught of their fucking adverts .

  25. the r sys have just 20mm outer width -> crap aerodynamics with a 23mm tire (thats probably even wider than labeled as the case with many clinchers). most cheap ~23mm wide box section wheels outperform the r sys by a good margin unless you put on a 19-20mm tire.

  26. Good data, but not an informative video when it comes to making a buying decision. Nobody buys a wheel to drive around an outdoor velodrome like this. There are hills, mountains, stop and acceleration in the real world.

  27. GNC give very different results, 4x less savings! average 0,5kph @200watts not 2kph!!! Cycling weekly seems not trustly

  28. This is twice the amount that manufacturers like Marvic claim – which would be twice the amount of what really happens.
    Try doing this on an indoor track with top track cyclists. Dual world track champion Shaun Eaddie says a disc wheel is worth 1/10th sec in a 200m sprint.
    I raced in the early 70's and our times at club races using the same track were just as fast as today's. I still use steel and light weight aluminium rims, bladed spokes, cup and cone hubs.
    Im reminded of one of Chris Hoy's training bikes. He added 4 x 10kgm weights and used it to ride up hills. This is how you punch out 2,100 watts.

    Ask yourself how many races have you lost by less than a second? Considering high performance tyres are just as good as carbon wheels and cost less than $200.

  29. A set of Enve 4.5’s one of the most expensive wheel sets money can buy. How are we expected to rule out the quality of the hubs and bearings on a set like this? So a set of 40/50 rim profile wheels on a more modest set, are we to see the same gains / or very little or no gains?

  30. l for one am happy for this video , l was correct in thinking l am not a pro so l dont give damn about over priced carbon aero wheels and JUST stick to lightest alloys rims with some aero profile but nothing insane 🙂 as for the difference in speed l ll just pedal faster 🙂

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  32. I did not know these guys were lovers! Wow, they dont sound gay, surprized they are doing each other! Sick little puppies!

  33. Seriously this weight and aero Bs is getting embarrassing man just grow your legs for God's sakes. Bring in 14 kg bikes and watch the rats abandoning ship lol.

  34. To everyone who thinks that this test is legit… How often you cycle on the track? Only this will discard this test as something you should rely on. Thanks

  35. "Aero" is a joke, a ridiculous lie. How pathetic are you that you buy into such nonsense? Calling all pathetic weight weenies, "aero" myopes, we need your wallet now………………………………..

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