Has anyone seen windtunnel data on an H3 disc? I was looking at a NOS wheel at a decent price, but it seemed to me this wheel would be slower than a regular disc with a smooth surface.
It was a bit slower, but was lighter than the Hed discs. That being said, H3s aren’t that far off a disc in terms of aero.
From Velo News 2002:
A new product out of Hed’s Spanish factory is a rear disc wheel withthe Hed3 structure inside it, called the “Hed 3D Disc.”
Armstrong and his team did not use it in the prologue, though, insteadopting for Mavic rear discs. The explanation, according to Armstrong andU.S. Postal aerodynamics advisor John Cobb, is that there is a clearanceissue.
“When we (Trek engineers and Cobb) designed those time trial frames,we never dreamed that they (U.S. Postal riders) would use bigger than a19mm tire in there. But they will only use 22mm tires because they areafraid about getting flat tires. On sharp corners, a 22mm tire hits theinside of the chainstays. The deep cut for the tire in the center of theMavic disc reduces the side flex of tire sidewall when cornering enoughthat it won’t rub. The 3D Disc is fast, but it would have been stupid tohave made another frame mold just so that wheel could clear. On less extremecourses, there is no problem. In fact, Lance used the 3D Disc in the Dauphiné(where he won the overall last month). U.S. Postal might still use the3D in the team time trial, though, because the clearance problem that isa much less curvy course.
Our wind tunnel tests show the 3D Disc is way faster than flat discs.It is also faster than the Mavic, but not nearly so much – maybe eightpercent, because the Mavic is also somewhat lens-shaped. The Mavic is prettygood anyway.”
**
That was back in 2002 and many new designs have happened in the past 8 years.All in all I think in many conditions it is somewhat fast than the HED3 but may not be quite up there with other disc’s of today.
It is not a flat disc the tri spoke area has a rise of about 3/8’’ above the flat panel area.Not sure if there was any real data done on that aspect of the design.
I have tried many wheel combo’s over the many years I been doing triathlons and have returned to HED wheels and for the past 5 yrs use them for my race wheels.
The HED 3D Disc works for me I like the look of it,rides great.I took the basic design of the HED 3D Disc and created my own wheel because they were only made with the Alum. brake surface and I ride full carbon tubular.I also reduced the the rise of the tri spoke to just under 3/16’" by creating a thicker surface between the spoke area for a flatter disc surface but still has the unique look.
You can see pictures of my wheels on my profile.
Scott
Also what is NOS?
I have a HED3D ‘custom’ from Clutch Cargo, and used it for the first time a couple of weeks ago in a 44km TT. No scientific data whatsoever, but it rolled fine, and it looks really cool. Not sure what HED’s own in house design was like, but the one from clutch is freakin rock solid, no flex, as it is essentially a HED3 which is already stiff, with two full carbon covers applied.
H3D way faster than a flat disc?
Any engineer types care to speculate as to how that could be?
Not that I don’t trust john cobb but a LOT of times his comments are taken out of context (like, two bottles is faster than none, etc)
**H3 way faster than a flat disc? **
Were you referring to this? >“Our wind tunnel tests show the 3D Disc is way faster than flat discs’”
yes, typo, sorry
**H3 way faster than a flat disc? **
Were you referring to this? >“Our wind tunnel tests show the 3D Disc is way faster than flat discs’”
From Velo News 2002:
A new product out of Hed’s Spanish factory is a rear disc wheel withthe Hed3 structure inside it, called the “Hed 3D Disc.”
Armstrong and his team did not use it in the prologue, though, insteadopting for Mavic rear discs. The explanation, according to Armstrong andU.S. Postal aerodynamics advisor John Cobb, is that there is a clearanceissue.
“When we (Trek engineers and Cobb) designed those time trial frames,we never dreamed that they (U.S. Postal riders) would use bigger than a19mm tire in there. But they will only use 22mm tires because they areafraid about getting flat tires. On sharp corners, a 22mm tire hits theinside of the chainstays. The deep cut for the tire in the center of theMavic disc reduces the side flex of tire sidewall when cornering enoughthat it won’t rub. The 3D Disc is fast, but it would have been stupid tohave made another frame mold just so that wheel could clear. On less extremecourses, there is no problem. In fact, Lance used the 3D Disc in the Dauphiné(where he won the overall last month). U.S. Postal might still use the3D in the team time trial, though, because the clearance problem that isa much less curvy course.
Our wind tunnel tests show the 3D Disc is way faster than flat discs.It is also faster than the Mavic, but not nearly so much – maybe eightpercent, because the Mavic is also somewhat lens-shaped. The Mavic is prettygood anyway.”
**
That was back in 2002 and many new designs have happened in the past 8 years.All in all I think in many conditions it is somewhat fast than the HED3 but may not be quite up there with other disc’s of today.
It is not a flat disc the tri spoke area has a rise of about 3/8’’ above the flat panel area.Not sure if there was any real data done on that aspect of the design.
I have tried many wheel combo’s over the many years I been doing triathlons and have returned to HED wheels and for the past 5 yrs use them for my race wheels.
The HED 3D Disc works for me I like the look of it,rides great.I took the basic design of the HED 3D Disc and created my own wheel because they were only made with the Alum. brake surface and I ride full carbon tubular.I also reduced the the rise of the tri spoke to just under 3/16’" by creating a thicker surface between the spoke area for a flatter disc surface but still has the unique look.
You can see pictures of my wheels on my profile.
Scott
Also what is NOS?
Thanks much. Maybe I will pick this up. It does look awfully cool. Downside is that it is tubular, which I’m not a big fan of. Unfortunately, there isn’t many options for 650c clincher discs these days.