Pretty much any disc creates forward lift. They work like a sail on a boat. I suspect the Sub 9 just faded away after the Super 9 was released.

Zipp used to claim pretty much identical savings of the Sub- and Super 9, so I guess they just figured the to keep the better product. Discs tend to be less laterally stiff than a spoked wheel, so the Super 9 probably corners a bit better and is less likely to have brake rub when you are out of the saddle. The Sub 9 was also designed back when a 23 was about as wide a tire as anyone used and I would think the Super is less sensitive to tire width.

It it makes you feel any better, the old Zipp catalog only claimed a 2 watt savings for the Sub and Super 9 over the 900 and that was an on-bike, with rider comparison at 10 degree yaw. If you are going fast enough to do a disc wheel justice, you are unlikely to see more than a 5 degree yaw.

I doubt the Super 9 was a direct replacement of the Sub 9, Zipp claims that " the bulge’s vertical compliance keeps the Sub-9 glued to the road when cornering and yields a comfortable ride, hour after hour. This makes it the ideal choice for long-course triathletes to bounce out of Transition 2 for the run with fresh legs after a blistering bike split."
The Super 9 is Super stiff, kind in the opposite corner from the Sub 9.

The Super 9 is "super stiff?" The sub 9 is the "opposite?" I don't want a disc that's the opposite of stiff.

I've found it to be an exceptionally comfortable disc. But I choose tires well, whereas you may not.

No comfort issues riding my Super 9 either. Use good tires like James said and your good

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Ok, i get your point, hope you got mine. Just to refresh, Zipp says about the Super 9 " This relatively simple-looking shape results in a wheel that’s as fast as the Sub-9 but stiffer than any other disc we make". Stiffer than any other disc sounds pretty stiff, doesn´t it?

What does "stiff" mean to you?

Please don´t spoil my post, let´s concentrate on the topic, why did Zipp stop production of the Sub 9? Maybe that can help me choose between the two disc wheels. Thanks in advance and hope you will understand.

I'm not spoiling your post, I'm trying to help you understand the difference between products.

The Sub9 was a much more complex molding process requiring a bladder mold for the bulge. And the bulge design basically became much less advantageous with the shift to wider tires and the general trend of most bikes actually having aerodynamic tube shapes. The Sub9 would also have been almost impossible to make in a carbon clincher version, so again, with the general shift to clinchers even among the pro tour, the wheel just ceased to make sense.

Yes, for you, on a Softride - or me on a Dimond - the Sub9 would be a faster wheel because we do not have a seat tube. But I still wouldn't ride it because it was/is tubular.

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Thanks a lot, great information there.

Are we sure about the Sub9 being a better fit aerodynamically compared to the Super9 in a beam frame?

Narrower would certainly be more aero, but the bubble style shape was created to hide the tire and smooth the transitions which the Super would also do, but without those extra transition areas back to the narrow profile.

I have not modelled it, but I could probably be convinced either way. I run a Hed Jet Powertap myself, due to some information about lenticular discs being best in a beam frame.

I see that Flo & the HED Stinger still use the 'bulge' disc shape though; albeit constructed differently i.e. as a skinned wheel.

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29 years and counting

The sub 9 had some fit issues with some (narrow) frames, too.

I'm sure it depends on tire choice and which particular bike. But, the rough summary, from Josh - based on my very easily faulty recollection, was that when the leading edge is either exposed or needs to clean up airflow of a round or otherwise "bad" seat tube, the Sub9 was faster. The Super9 came about because as tube shapes improved, the flow off of the wheel became more important, and that was why the Super9 was designed in the way that it was.

I wonder if they actually ever tested both discs in a 2001 or 3001 frame... I will ask.

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"Non est ad astra mollis e terris via." - Seneca | rappstar.com | FB - Rappstar Racing | IG - @jordanrapp

Thanks Jordan,
Yes, we did test it that in our 3001 and with 21mm tires, the sub-9 has the slight advantage in the beam bike but with 23, 24, 25mm tires, the Super9 has the advantage. Often lost in the memory of these (including mine) is that the sub9 was developed at a time when we thought 21mm tires were pretty wide and the super9 followed by a few years and it was clear that 23+ was going to be the new norm..

For pure ride quality I still love the Sub9, but frame fitment issues (it was 28.5mm wide when nothing else was..) and the tendency of the market to buy what the pros were riding (almost all on Super9 for stiffness and weight..even though neither of those matter all that much) combined with the looming market shift to 23+mm tires killed the Sub9. It also didn't help that it was the most complex and expensive wheel we ever tooled up for which made updating it all that much harder to justify!

Best
J

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Thanks very much Josh and Jordan!

Josh, would you say that a sub-9 with 21mm tires is better, worse or equal to a super 9 with 23mm, both tubulars, considering both aero and CRR for a beam bike such as the Dimond? I presume adjusting tire pressure could compensate partly for ride comfort in the case of the super 9, although possibly at the expense of CRR?

If I remember correctly, it required a dedicated machine to do the combo bladder+honeycomb-with-skin molding process and each machine was like $100K. And you had nine of them... Yeah...

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Wild guess: Super 9 is easier to make, requires simpler tooling, or easier to source materials.

Which of course means a higher profit margin.