I’m building out a TT bike for stage race TTs and I’m kind of intrigued by tossing a pair of H3s (or H3Ds) on it.
Love the aesthetics…but I don’t know about the real world aerodynamics. Anyone have any data on how they stack up with, say, a pair of Zipp 808s?
Not “the best” in all situations, but still pretty darn good. The big question to me is what do they do to you mentally for a TT? If they get you in-the-mode, if you feel like a speed machine when you’ve got them under you, go for it.
H3’s are still relevant and a good wheel (afaik H3D’s aren’t UCI legal). Pros choose them as they’re good over a variety of yaw angles and predictable. The 808 is faster.
Still legit. If you’re fast or there’s no wind the H3 (with the right tire) is still the fastest front wheel out there. Disc would be a hair better in the rear, especially in a crosswind.
The laws of aerodynamics don’t change, but our ability to understand them (hopefully) does.
The HED 3 was developed largely by DuPont for Specialized, then the design wound up with HED wheels. That means a significant amount of money went into the research and development, more than a bicycle wheel company would have had at the time of its development.
The design concept is still valid. Still efficient across a wide envelope of yaw angles at attainable velocities.
The wheel has recently been modified congruent with the trend toward wider rim beds and wider tires.
There was a version with a deeper section rim fairing. That was evolved mostly because of Lance Armstrong ad Viatchslov Ekimov, who both used the wheels in Tour de France and grand tour time trials. They consistently averaged over 28 MPH, so the deeper rim section on those versions may have provided an additional benefit. For riders like you and I, who average below 28 MPH even on a good day, the deep section probably crosses the threshold of the extra weight perhaps inkling any additional high speed aero benefit and the wheel may feel less stable.
For the tubular all carbon version (not the new wider version though), what is the best size tubie to use on it?
Would a 22mm veloflex carbon be too wide for it? Better to find a 19mm Vittoria Corsa CX?
There was a version with a deeper section rim fairing. That was evolved mostly because of Lance Armstrong ad Viatchslov Ekimov, who both used the wheels in Tour de France and grand tour time trials. They consistently averaged over 28 MPH, so the deeper rim section on those versions may have provided an additional benefit. For riders like you and I, who average below 28 MPH even on a good day, the deep section probably crosses the threshold of the extra weight perhaps inkling any additional high speed aero benefit and the wheel may feel less stable.
Hmmm, I would have thought that the opposite would be true? At higher speeds riders will experience far lower yaw angles, and therefore the benefits of deeper rims become reduced. My understanding was that the higher the yaw, the more a deep rim/disc will benefit you. The irony of this, of course, is that it means for many ‘average Joe’s’, on the days when they will most benefit from a deep section front wheel (windy days, hence high yaw), they are too uncomfortable with the handling to use them.
Check out the top TT results from this year’s races and you will see more H3C’s than any other wheel. They are fast, always have been, and always will be.
Jack
yeah, it was good enough for lance, wiggins and the english tt champs but pretty sure its going to hold you back.
If they are good over the variety of conditions, why is the 808 faster? Is it something i should look at upgrading?
When you look at HED’s own aero data, the H3 series is fast, but not faster at zero yaw than deep spoked wheels, and it stays very consistent across a range of yaw angles, whereas deep rims get faster up to the point that they stall. Unfortunately, HED pulled the aero charts they used to show off their website. Below is an old graphic from Zipp.
Based on this, the H3 can’t compete. But, Team Sky, with the biggest budget in pro cycling and a philosophy of marginal gains, used them, and now uses the Shimano 3 spoke. Tom Dumoulin, a favorite to be the next TT world champion, just scorched the Vuelta TT on a 3 spoke front.
Clearly, something else is going on here. I have heard that the way the 3 spoke interacts with the fork improves its performance beyond what you see in the wind tunnel, though Sky’s Pinarellos have forks with very wide legs to avoid turbulence from the wheel. Clearly, teams with a lot of resources and interest believe it is the fastest option for their riders, though some TT legends (eg. Tony Martin, Fabian Cancellara) use “conventional” wheels.
And, as already pointed out, what pro cyclists or triathletes use may not be relevant to mortals. Top TT riders average over 30mph, so they don’t see much yaw. I average…well…somewhat less. As has also been pointed out, your deep wheels may not be helping you unless they are also scaring you, since their advantage is at wider yaw angles.
The H3 went out of favor for a while because it requires a very narrow tire to perform well–19-20mm. Pros have gone to much wider tires for better comfort and lower rolling resistance. HED developed the GT3, which is tubular only, at the request of pro teams a few years ago. Same design, just wider, so it performs well with a 22-23mm tire. At Eurobike last week they showed a new H3+ that uses their 25mm wide rim.
Personally, I retired my H3. I loved the way it sounded and behaved in crosswinds, but a 20mm tire at 120psi is not as nice to ride as a 25mm tire at 100psi…it looked and felt like you were riding an ice skate on the front. Chances are the aero gains of the narrow tire were offset by the better rolling resistance of the wider tire. But the H3+ has me interested, especially if they release it in the blacked out rim.
Because, let’s face it, we are age groupers. Our potential performance is enhanced far more by feeling fast because you look fast than it is by a watt or two of drag savings.
So, it comes down to who you want to be like–Wiggo, Froomey and Dumoulin, or Der Panzerwagen and Spartacus.
They not only made the new trispoke wider, but less deep in the rim section as well…that decision was a head-scratcher for me.
I’ve got some wheel-only data I’ll be showing soon that shows an H3, even with a VERY narrow tire (19c Bonty AeroTT) isn’t as fast as either a Jet 6+ or Roval CLX 64 with a tire that measures ~24mm wide mounted on them from 0 to 15deg of yaw.
So, at this point, I’d have to put my vote on “outdated”.
Yet when AndyF and I tested the H3, we couldn’t get any wheel tire combination to come close to the H3/AW19 front. Some of the 20mm Supersonics I’ve measured mounted come in at 19mm. Your tests indicating better rolling resistance than the AW19, show the Supersonic might be faster. I haven’t measured my C2 Jet9 faster in field testing with any tire either. I race each wheel under different circumstances, so I’m not knowingly biased or financially biased toward either being faster. The Jet 6+ being faster would be surprising, so I’m looking forward to your data. Not owning a Jet 6+, I am financially biased, hoping it is faster, so I could sell two wheels and only have to own one.
Yet when AndyF and I tested the H3, we couldn’t get any wheel tire combination to come close to the H3/AW19 front. Some of the 20mm Supersonics I’ve measured mounted come in at 19mm. Your tests indicating better rolling resistance than the AW19, show the Supersonic might be faster. I haven’t measured my C2 Jet9 faster in field testing with any tire either. I race each wheel under different circumstances, so I’m not knowingly biased or financially biased toward either being faster. The Jet 6+ being faster would be surprising, so I’m looking forward to your data. Not ogwning a Jet 6+, I am financially biased, hoping it is faster, so I could sell two wheels and only have to own one.
Interestingly enough, the H3 I tested was slightly faster aerodynamically with a 20c SuperSonic mounted on it as well 
HED used to (still do somewhere?) have a chart which allowed you to show the yaw/drag curve for a particular wheel once selected. This diagram did show at low yaw the H3 to be fastest but as soon as yaw went out to iirc about 10 degrees it did not see the drag drop away like the deep spoked wheels.
HED used to (still do somewhere?) have a chart which allowed you to show the yaw/drag curve for a particular wheel once selected. This diagram did show at low yaw the H3 to be fastest but as soon as yaw went out to iirc about 10 degrees it did not see the drag drop away like the deep spoked wheels.
This is why you have to ride super fast, producing low yaw.
HED used to (still do somewhere?) have a chart which allowed you to show the yaw/drag curve for a particular wheel once selected. This diagram did show at low yaw the H3 to be fastest but as soon as yaw went out to iirc about 10 degrees it did not see the drag drop away like the deep spoked wheels.
This is why you have to ride super fast, producing low yaw.
well yes but the point I was making was this is at odds with the chart posted by Zipp. Unless you do your own testing it just comes down to who you believe, as is usually the case!
They not only made the new trispoke wider, but less deep in the rim section as well…that decision was a head-scratcher for me.
I’ve got some wheel-only data I’ll be showing soon that shows an H3, even with a VERY narrow tire (19c Bonty AeroTT) isn’t as fast as either a Jet 6+ or Roval CLX 64 with a tire that measures ~24mm wide mounted on them from 0 to 15deg of yaw.
So, at this point, I’d have to put my vote on “outdated”.
I think the primary focus for the GT3 was low yaw (for the pros) and they might think that the very slight increase in drag by a less a deep section at low yaw would be offset by the handling and weight advantages (pro TT’ers probably still like low weight, reasonable or not).
I did field measurements a couple of years ago showing an H3 and a Jet 6 C2 (23mm rim), both with 20mm Supersonic, was within a watt or so at ~0 yaw (standard deviation around 1-2W or so IIRC). Would love to see your data - and which tire you used. I guess this was at the Specialized windtunnel? (side note, do you have a feel for the accuracy and repeatability of that tunnel?).
I’m interested to see their new H3+, I really hope somebody will take some pictures and get some data on it at Interbike, since nobody seemed to do so at Eurobike. That said, from a pure and simple frontal area calculation a standard deep spoked wheel with 18 CX-Ray spokes will have ~35cm2 of spokes while a three-spoke will have 3-4 times that, i.e. Cd of each spokes has to be more than 3-4 times lower for them to be better - of course, this is neglecting any interaction with the rim, fork, etc.
… Our potential performance is enhanced far more by feeling fast because you look fast than it is by a watt or two of drag savings.
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Agree 100%!
Any ETA on this data?