Aero data from 19 wheels by Hambini

[spdntrxi]

anytime I've seen NSW compared to Firecrest.. no aero improvement.. so it does not matter.

[RyanH]

@hambini

Any chance you could take a crack at quantifying braking performance of the various wheels?

[alcatraz]

That's not easy. A brake test should include dry/wet braking and 3+ different pads.

Do you simply measure braking distance or build a big contraption with a heavy roller to slow down.

Do you measure brake lever pressure?

/a

[hambini]

I posted in the comments to the article, but on-rider testing is difficult, particularly if not using aero bars to really lock the test rider(s) into a replicable position. Even then, you have to be really cognizant/careful to replicate torso, head/neck, hands, etc.

Tire choice can also be very wheel-specific and it's not clear if each wheel was tested with its optimal tire. If all wheels were tested with the same tire, then some wheels were advantaged while others disadvantaged depending on if the chosen tire was a good choice for that particular wheel.

I have replied on the blog post but for completeness I'm writing the response here.

The rider was aligned with a laser. His hinges were "targeted" and then aligned with that.

And I take on board the comments about the tyres. They were all conti GP 4000S II. It is possible for some variation in there but changing the tyre changes more than one control variable.

Hambini

[ryanw]

Would like to see how my 4.5s compare to 404s and the 3.4s...

[bilwit]

Would like to see how my 4.5s compare to 404s and the 3.4s...

I think the generalizations we can take from the results is that depth trumps profile but is pretty insignificant at "normal" speeds ~30kph between any mid-depth wheel. Judging from the performance of the 7.8s and the 3.4s, it seems to me that at 30kph the 4.5s would fall in the Shimano C50/C60 category at 185w and if you assume it also follows those same trends, it should be ~600w at 50kph, perhaps a bit under but in any case, I certainly wouldn't expect them to be faster than the 404s at all given that they're less deep (48mm/56mm versus 58mm/58mm) AND if you take the 3.4s as guideline, the ENVE profile may not be very fast for what it is (or costs).. but that's ignoring all the other things like ride comfort, stability, stiffness, braking performance, etc

[kgt]

That's the moral IMHO:

"In the bike industry, wheel aerodynamic testing has generally been conducted by two groups of people - Wheel manufacturers and journalists. Wheel manufacturers will usually adjust tests to make their particular wheels look more favourable than their competitors in testing. This is usually achieved by a combination of adjusting speeds and angles. The reality is this type of test is not impartial. Journalists on the other hand tend to visit their local university and ask some clever boffin to conduct their testing for them and give them the results or go to their local velodrome, hold a speed and see how much power the wheels consume. Both of the above testing methodologies are not representative of the real world."

So whenever a new 'scientific' test by a big manufacturer or a popular magazine comes up, just keep calm. Probably it is not that credible.

[ryanw]

Time to buy some Bont 60s and remove the decals me thinks....

[MagicShite]

hambini, any good idea where the HED Jet 6s lands?

I gotta say despite the very good deal on Yoeleo wheels, I very much still prefer alloy braking surface.

[hambini]

hambini, any good idea where the HED Jet 6s lands?

At a guess it would be in the top third. As we are not funded in anyway, most of these wheels were donated from people we know/bike shops, I will see if I can get a set.

I'm going to add some more bits to that test about test protocols. Some of the individuals on Slow Twitch have questioned mine and my colleagues "Aerodynamic credentials".

Just to clear this up. The list of wants:

Lightcycle V and U profile
Farsports
Hed

Any others? I can't promise but I can certainly try.

Thanks
Hambini

[morganb]

hambini, any good idea where the HED Jet 6s lands?

At a guess it would be in the top third. As we are not funded in anyway, most of these wheels were donated from people we know/bike shops, I will see if I can get a set.

I'm going to add some more bits to that test about test protocols. Some of the individuals on Slow Twitch have questioned mine and my colleagues "Aerodynamic credentials".

Just to clear this up. The list of wants:

Lightcycle V and U profile
Farsports
Hed

Any others? I can't promise but I can certainly try.

Thanks
Hambini

I'm interested in all of those plus any of the newer Roval wheels (21mm internal models).

[morganb]

The Rovals I have only seen in one test where they performed very poorly (bikeradar), but there was hardly any information on the test procedure and the gaps between wheels seemed unrealistically large.

[ichobi]

Rovals are technically hed. Specialized bought HED patent. So if he's are aero so should Rovals.

Sent from my Pixel 2 XL using Tapatalk

[jhalmar]

Please remove this post if it bothers someone but here is Tour 10/2017 wheel test data where they tested middle depth disc brake wheels and Roval CLX 50 disc is included. More info can be found by purchasing the actual magazine.

[Beaver]

hambini, any good idea where the HED Jet 6s lands?

At a guess it would be in the top third. As we are not funded in anyway, most of these wheels were donated from people we know/bike shops, I will see if I can get a set.

I'm going to add some more bits to that test about test protocols. Some of the individuals on Slow Twitch have questioned mine and my colleagues "Aerodynamic credentials".

Just to clear this up. The list of wants:

Lightcycle V and U profile
Farsports
Hed

Any others? I can't promise but I can certainly try.

Thanks
Hambini

Hi Hambini,

Reynolds Aero 46 or 65 would be interesting for comparison as they are the only ones with a real teardrop shape.

In the Tour Mag. tests they were always some watts worse than the torodial shapes.

Regards,
Beaver