Anybody notice these on HED’s website? The data on the 9 is remarkable IMO. I reached out to them via twitter and their website to see what type and what size tire they used in testing. No response just yet but it’s the weekend so it might take a day or two. FWIW, I enquired about a Jet+ disc a month ago and they mentioned to me over the phone that they’re recommending 25mm tires for all of their new Jet+ wheels.
Edit: HED got back to me this morning with the following reply:
We ran 22mm conti attack. It makes the tire to rim transition very smooth.
Andy Tetmeyer
Hed Cycling Products
Not going to lie, I didn’t expect that. I thought for sure they would have tested a 23mm or 25mm GP4000S.
HED Jet 6+
HED Jet 9+
manufacturers are optimizing their marketing data for GP4000s tires… shooting for those awesome drag numbers at 17.5 degrees of yaw.
HED Stinger tubulars used to be faster than their clinchers… now that everyone’s using the magic aero GP4000s that has changed.
And the majority of people need not be concerned with anything above ~12degree or so of yaw
.
Agreed. I don’t think I would want a front wheel as deep as a Jet 9+ if it is windy enough for yaw angles >12.5 degrees. The Jet 6+ has only a few more grams of drag than the
Jet 9+ at yaw angles <12.5 degrees which probably makes it a better choice as a front wheel for most people. I wonder how much faster a disc is then a Jet 9+.
jet 6 has
I wonder how much faster a disc is then a Jet 9+.
^^ I always had a hard time believing that chart. I can’t believe a disc wheel such as that jet disc can’t even delve into the negative drag area at any yaw angles haha. SO sad…
Disc wheel testing protocol can vary quite a bit. Unlike most other wheels, you can’t use a front wheel. So then you are going to have non symmetrical drag on each side. Which do you publish? Or do you average both? Do you include a cassette on the wheel or not, and if so, what cassette? and so on.
^^ I always had a hard time believing that chart. I can’t believe a disc wheel such as that jet disc can’t even delve into the negative drag area at any yaw angles haha. SO sad…
0 deg yaw numbers are the same as the non + models when you compare to the data they released in 2012
if that is with a 25c tire that would be remarkable.
even with 23c tire I wonder.
I never paid attention to that Hed Jet Disc graph since it is old data and doesn’t make sense when compared to the current Jet non-disc plots.
What TT bikes even fits a 25mm tire on a Jet + wheel extrusion (which would make it look more like a 28)? Certainly not Cervelos.
What TT bikes even fits a 25mm tire on a Jet + wheel extrusion (which would make it look more like a 28)? Certainly not Cervelos.
The new cervelo TT bikes probably do. They were kind of specifically designed to handle 25c
Even on the new P5, I’d bet that would be a fairly tight fit. I’ve seen a few Ardennes + wheels running 25c tires on them and the tires were really fat.
Personally I think the new wider Ardennes are a great idea for a road bike, but I just don’t see the point for triathlons or TT’s. How often do you really worry about high yaw angles anyway?
if that is with a 25c tire that would be remarkable.
My sentiments exactly.
Personally I think the new wider Ardennes are a great idea for a road bike, but I just don’t see the point for triathlons or TT’s. How often do you really worry about high yaw angles anyway?
If you could achieve the same low yaw performance with a 25mm tire I’d jump on that rim in a heart beat. Run it at a lower pressure for greater riding comfort which is a factor in triathlon IMO.
What TT bikes even fits a 25mm tire on a Jet + wheel extrusion (which would make it look more like a 28)? Certainly not Cervelos.
The new cervelo TT bikes probably do. They were kind of specifically designed to handle 25c
I am running a Super-9 w/ 25mm GP4000s on my P5
0 deg yaw numbers are the same as the non + models when you compare to the data they released in 2012
if that is with a 25c tire that would be remarkable.
even with 23c tire I wonder.
I don’t trust any data by any manufacturer that isn’t accompanied by test details (i.e. test facility, tires, tunnel speed, fixture tare or not included, etc.)
0 deg yaw numbers are the same as the non + models when you compare to the data they released in 2012
if that is with a 25c tire that would be remarkable.
even with 23c tire I wonder.
I don’t trust any data by any manufacturer that isn’t accompanied by test details (i.e. test facility, tires, tunnel speed, fixture tare or not included, etc.)
it’s like they just extrapolated a number… “well if 23mm stalls at 15 degrees then 25mm must stall at 30 degrees. Let’s just plot the line and connect along the same slope.”
0 deg yaw numbers are the same as the non + models when you compare to the data they released in 2012
if that is with a 25c tire that would be remarkable.
even with 23c tire I wonder.
I don’t trust any data by any manufacturer that isn’t accompanied by test details (i.e. test facility, tires, tunnel speed, fixture tare or not included, etc.)
it’s like they just extrapolated a number… “well if 23mm stalls at 15 degrees then 25mm must stall at 30 degrees. Let’s just plot the line and connect along the same slope.”
My only counter to the above sentiments is that HED has been around long enough to know that magazines (TOUR, etc) will do their own wind tunnel tests as will other manufacturers and if the data that they (HED) present on their own website is significantly off they’ll get tarred and feathered.
Thanks for that. So nothing groundbreaking at relevant yaws. I guess the only question now is what tire/width was used.