Look at Tom A's recent testing at Specialized. I think the graph is in this thread.

But that is just aero. I had said aero plus crr.

scroll up for the Tour Mag chart that used Conti's own rollers, but the GP TT compared the same with the TC on the same roller, which compares the same to the SS 23 on Tom A's roller.

at this point I'm not at all concerned with high yaw, which was the red herring that got everyone all excited about the GP4000s 23mm. I've done well with magic attack backwards front and rear, Attack Force front and rear, and also TC 24mm front and rear.

Any of these will do well IMO, unless you're at TT nationals or something and then you actually have to sit down and do the math. In which case I really like the 23mm SS aero data from Tom A's blog as well as the top of class Crr

Grain of salt, all of my info is taken from other sources and then extrapolated with reasonable amount of informed opinion

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THIS. All of it.

the take-away is that Crr more than makes up for any aero sins.

and, the faster you go, the lower the yaw angles, and the higher the penalty for bad Crr tires.

so yes, in a lot of situations, the TC is very good, at least compared to the most aero tires. That said, there are other tires just as fast rolling that might be more aero because they're vulcanized and not open tubular like the TC. The SS 23mm is one of these and had reasonably good aero numbers when Tom A. tested in the Specialized tunnel. The GP TT 23mm might be another. Zipp's best and narrowest offering might be a third. A "magic" Attack 22mm backwards might be a fourth.

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I just saw that by looking at the CRR spreadsheet and the aero spreadsheet it looks like the supersonic is the best combination of aero and rolling resistance. It looks like the attack is similar to the TC.

The problem that I have heard is that the supersonics are very fragile. I have yet to ride an Ironman race in the US that I would feel very comfortable with a fragile tire. Although a ~4 watt total benefit in aero plus CRR would be damn tempting.

Right. But if you go over to the aero data spreadsheet and look at the Watts @ 50kph.

It's a little hard to compare/graph directly, since he only used the HED Jet6+ for two tires. But you can do some speculative analysis. The 22mm SW Turbo kicks the shit out of the Turbo Cotton on aero on the Jet6+. The Supersonic beats the 22m SW Turbo on the Flo9. The 22mm Attack (narrowly) beats the 22mm SW Turbo on the Flo9.

And then look at the Crr spreadsheet and the power for two tires at 50kph, you can get a pretty good idea that things aren't going to end well for the Turbo Cotton. You can create some rough graphs using the data from the two spreadsheets.

Just my two cents. I have ~500 race miles on two pairs of Supersonic, with some relatively rough chipseal, etc. Even hit a few potholes. No flats. No cuts in my tires.

Run them with a few ounces of sealant in latex tubes, and you're going to have a very fast, fairly reliable set of race tires.

The SS23 has great aero and Crr.

It depends on what which tests and charts you want to give priority to. I guess there was some chart floating around that said the TC 24 had good aero properties, but I was skeptical at the time, and now that we have other data (from Specialized's testing) that show it does poorly, that's what I believe. Like I said earlier "open tubulars" traditionally do not do well aerodynamically. They have a squat profile and a lip on the side of the tire that apparently messes with airflow.

Crr isn't a definite number either. Samples vary, and for us guys doing roller testing there can be fairly large error bars as well. And then there are those who claim roller testing is a poor representation of what happens on the road, with roughness, vibration losses, etc. It's one of those things that is difficult to prove.

I haven't tested a TC, but it's a Vittoria Corsa casing, with a modified tread. I have tested a lot of Vittorias, and though they are good, they consistently fall short of the SS23. Based on the testing I've seen compared to what I've done, and scaling and extrapolating the numbers, I'd put the TC24 at about the same Crr as the SS23. I don't know of anyone who has tested them both other than Tom.

It's viable as a rear tire (where aero doesn't matter as much, and Crr matters a little more), but I wouldn't put it on the front.

BTW, this is all hair splitting stuff for those of us who like to split hairs.

Thanks. I appreciate you guys going through the thought process.

You say splitting hairs and are right but something like 3-4 watt difference adds up to minutes (2-3 ish I think) on an Ironman course. In the 35-44 AGs there is often a number of guys in that window right at the bubble for Kona. Split enough hairs and it could mean the difference between going to the big island and not.

The problem that I have heard is that the supersonics are very fragile. I have yet to ride an Ironman race in the US that I would feel very comfortable with a fragile tire. Although a ~4 watt total benefit in aero plus CRR would be damn tempting.

I started using them for TTs 8 years or so ago. They aren't fragile. They won't be as puncture resistant as one of the Contis with a vectran belt, but I think they are pretty close in that respect compared to Vittoria (who make the TC also). The tread compound also seems to be very resistant to cutting like all the Conti tires. The tread is very thin, so they won't last long, and you definitely want to avoid skidding them. Use newish ones for important races.

When you race, do you ride on the shoulder? If you aren't required to, I wouldn't. That's where all the wires, glass, nails, and gravel accumulate. Vehicles keep the road pretty clear starting at the white line.

I think you overestimate the aero penalty of the TC. Looks to me to be 2.5 watts according to Tom A. At 50kph you're getting back 3.5 in Crr. You'll never see those yaw angles where it really makes a difference.

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Eric Reid AeroFit | Instagram Portfolio
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“You are experiencing the criminal coverup of a foreign backed fascist hostile takeover of a mafia shakedown of an authoritarian religious slow motion coup. Persuade people to vote for Democracy.”

Should I cancel my order then?

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I probably overstated it. But I do see some pretty steep yaw angles on my home TT course, even averaging ~28MPH.

6 and 7 are the Zipp tires. The "open tubular" designation, if I understand it, has to do with the manufacturing process, vulcanized vs handmade. I have both the Zipp & Vittoria tires. The Vittoria tires do indeed have a definite ridge on the side of the tire where the tread meets the sidewall, and it's presumably this ridge that leads to their relatively poor aero performance. Zipp tires look nothing like the Vittorias, they visually look much more like the Contis, the transition between the tread and sidewall is seamless, there's a tiny line but it's not a raised ridge like the Vittorias. The Zipps do have a very light diagonal siping pattern somewhat like the GP4000s but not as deep. In the hand they feel just as supple as the Vittorias, unlike Contis which have always felt stiffer.

I test tires on the rollers and the Zipps tested very fast, on par with my control tire, a Vittoria triathlon. They certainly look much more aero than the Vittorias. I also do field testing but have never tried to test tires, thought it might be too granular to test using VE but might give it a try this spring for laughs. I raced on a Zipp speed 23/25 combination last season and at least my subjective impression is that they are very fast tires in the real world for whatever that's worth. I've also gotten inconsistent rolling resistance results from the Conti tires I've tested, I'd never use one for racing without testing to make sure it was fast.

Bottom line is I think that assuming the Zipps have poor aero performance similar to the Vittorias is a very dubious assumption.

I thought the Zipps were based on the Corsa like the old Tangente, but I see that they use the vulcanized 220tpi Diamante casing. Not an "open tubular" then.

Heck while we are at it, why hasn't anyone tested the Vittoria Pro Pista? It's very light at 150g in 23mm and has the same casing it seems: http://www.vittoria.com/.../diamante-pro-pista/

And after looking around the Vittoria site, I'm confused about graphene. If it really makes the tread *faster* then why is it used on the Rubino, but not on any track tires? Too low volume to bother? Or maybe the only thing thing making the Corsa Speed fast is thin tread. They have the heavier duty Corsa for people who want some longevity.

Aren't these Corsa graphene tests of the standard Corsa tire, not the Corsa Speed one?

Which tests?

rruff wrote:

Which tests?

The linked one: http://www.bicyclerollingresistance.com/...-corsa-graphene-2016
And this one: http://bikeboard.at/...-Welt-Pt.-2-th217501

I did find this update to the original testing by another guy but the language barrier makes it hard to assess the methodology: http://cyclesetforme.blogspot.co.uk/...raphene-reviews.html

Thanks, I hadn't seen the last link. Looks like a good recommendation for the Corsa Speeds.

He tested on rollers and on a climb. On the rollers he takes the measured power difference and divides by 4 to scale it to the road. He found the Corsa Speed to be substantially faster than the GPTT. About 10% lower Crr for the clincher.

Your 2nd link is a good example of variability, even with the same tires on purpose-built lab equipment. The differences between the results at Conti vs Specialized look pretty huge for those of us that like to split hairs.

Just wanted to confirm the width I found they were measuring out to a maximum width of 20.8mm and a rim depth of 66mm and the others 46mm depth. I've ordered a pair of GPTT and a SS 20c. Would either of these tires give away handling, wet weather reliable?

Thanks again

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"Train so you have no regrets @ the finish line"

Handling and wet would be fine. SS20 on the front. Is one of those a rear wheel?

Yeah I got two for the rear and one up front and before anybody asks ... no I don't own a tricycle lol I was going to go 2XGPTT but when I saw the width I got the SS in addition.

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"Train so you have no regrets @ the finish line"

quick one do SS23 and GPTT 23mm also measure more like 25mm similar to GP4000SII ?

The SS23 is smaller. I've heard the GPTT is pretty fat.