IIRC the 5000's are a bit faster than the 4000s II. Maybe a bit more aero as well.
With that being known, there is no harm in testing with the 4000s. You just know the final #'s are going to be a touch better than what you got.

I do all my personal testing with Zipp 808/disc but race a faster HED set up.

Tires/wheels those typically aren't the questions you're trying to answer, plus there is a ton of research on those things. When testing position/helmets/clothing are typically more important questions to solve.

Now if you've got unlimited time......!!!!

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Brian Stover USAT LII
Accelerate3 Coaching
Insta

Any reason why you test on something different than you race on? Just curious.

Also has anyone else here been to the Boardman? I was there last year and had lower than expected CdA from my baseline. A few friends have had similar results compared to other tunnels all else being equal.

So I don't put miles on my race tires & for consistency since that's what all my A2 tests have used. If I'm just testing and not racing it's also 2 less things to pack/ship/travel with. I'll happily go put in a 5-6h training day but ultimately I'm lazy in other areas like packing


There was a thread on the reason why. iirc bc they remove the tare where other tunnels do not. But you should search for that for positive confirmation

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Brian Stover USAT LII
Accelerate3 Coaching
Insta

Cheers for the reply. I will look for that.

Sorry for the derail. Back to Daniela.

I always just assumed that a super9/808 vs a HED jet disc / 9, would pretty much be a wash. Did your HED setup actually test faster with same tires etc being used on both sets?

Thx

She's still on long cranks, 172.5. Interesting she hasn't jumped on the short crank bandwagon. I finally made the change last year from 172.5 to 165 and am really sold, sure haven't lost any power with the swap, that's for sure.

Seems the Europeans tend to still run longer cranks, for instance see the long cranks fitted with the Canyon Speedmax.

Actually according to JP Ballard at Swiss Side, the GP4000 II is more aero than the GP5000. One of the least Aero tires is the GP TT, he stated in a blog last year that the aero benefits of the GP4000 made it a significantly more efficent tire overall than both the GP5000 and GP TT

As JP Ballard and his Swiss Side team have a background in Formula 1 aerodynamics, as well as one of the most sophisticated wind tunnels in the cycling industry, and supplc Team INEOS with their wheel, I would tend to go on their recommendation.... which is probably why Daniela is riding at GP4000

Since when is Ineos riding on Swiss Side wheels? They are all riding on Shimano wheels. I thought they were just partnered for aero testing.

Hmmm, the rolling resistance difference between the 4000 and 5000 is quite substantial. I do my own roller testing and the 4000 didn't that well. The faster you ride, the more the tradeoff shifts to an aero tire over a faster-rolling but less-aero tire. Probably depends on a course as well, I would think a flatter course would favor a more aero tire and a hillier course would favor the lower rolling resistance tire. The vast majority of triathletes are averaging speeds less than 25 mph in tris and I suspect most of us are better off giving up a bit of aero for the lower rolling resistance of the 5000.

In addition, she did ride the 5000s in Kona.

So maybe it's just an older pair of wheels that she is using for testing purposes only? Could be that simple...

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DFRU - Detta Family Racing Unit...the kids like it and we all get out and after it...gotta keep the fam involved!

boardman set their tunnel up on the cheap, i.e. without f1 knowledge on how to set-up, calibrate, use etc.

when mclarenf1 worked with specialized on their wind tunnel (after specialized had built and already started using it), they essentially had to start the specialized guys from scratch and tell them to forget everything they had been doing and thought they knew.

the experience of f1 teams using wind tunnels is unparalleled and i definitely wouldn't consider using the boardman tunnel as a result.

So maybe it's just an older pair of wheels that she is using for testing purposes only? Could be that simple...


Pro Triathletes at this level have multiple bike and even more multiples of wheelsets at their disposal.

So yes to this!

And it's not like the 4000's were dog's of tires - with latex tubes in them, they were up in the top-5 as I seem to recall in overall performance!

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Steve Fleck @stevefleck | Blog

You're correct, my mistake.

Which is why I would tend to trust the findings from Swiss Side... Also helps that they are proper aerodynamicists, not general engineers. Do Boardman and Specialized etc actually employ anyone with a deep level of aerodynamics experience and education?

I need to look for JP's podcast on the topic, but I think he said that at 25 mph, the GP4000 saves over 10w compared with GP TT - He said that the GP5000 was OK, just not as good as the GP4000

I use GP5000

We did this in the tunnel as well as Crr - the 4000 was good at lower yaw and the TT wasn’t so, but the TT still wins out on Crr combined with CdA:

https://www.aero-coach.co.uk/gp-5000-data

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AeroCoach UK
http://www.aero-coach.co.uk

Could be comparing all things equal to her last velodrome and making changes only to the bike, position, clothing, helmet, etc... Then doing tires last after getting all the other improvements?

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http://www.sfuelsgolonger.com

Some of the Ineos guys have been seen using the Princeton “whale wheels”. This might have just been at World’s last year