We have data on various brands here:

https://aero-coach.co.uk/...e-rolling-resistance

I use Vittoria personally

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AeroCoach UK
http://www.aero-coach.co.uk

can i, the rank amateur, presume to present a contrasting opinion? i'm foolish to do so but, well, i'm foolish, so i will.

first, thanks for the test. second, this comports with vittoria's own claims. third, kaboom! goes the 5000 TT. well, not so fast, people treat conti like their politics and religion. but every reason for choosing the 5000 TT is now the reason to choose the corsa pro speed (it seems to me).

fourth, i just want to push back a little on the latex tube argument, at least in tri. there is what people ought to do. then there is what people do. and in tri - even at the highest levels - what people actually do neuters the reason for innertubes. there will be absolutely... no... changing... of... tires... to suit the conditions. practically no triathlete, at least in no-draft racing, at any level, has ever thought the day before a race, hmm, i think i'll change my tires because of tomorrow's weather. but...

many triathletes, virtually all triathletes, have asked themselves what they might do (that is not too much work) in order to lesson the likelihood of a flat. the way you do that is placing the sealant in direct contact with the tire rather than placing the sealant inside a latex tube.

i try to make it a point never to debate 2 people. josh poertner and you. but there i went and did that stupid thing.

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Dan Empfield
aka Slowman

No you're quite right, and I suppose I'm coming at it from the perspective of a time triallist/track rider where it's a one shot thing and if you puncture then it's the end of the race really. Tubeless for triathlon, especially the longer it gets is a good idea and we tend to recommend GP5000 (or in good scenarios GP5000 TT) for triathlon customers buying our wheels for example.

What we also tend to see is people leaving their tubeless tyres on just that little bit too long, because of the hassle of changing them out and doing the setup again, which is something that's less of an issue if you are running tubes, but there's a place for both for sure!

The other side note to this is all the track data that we've got on clinchers vs track tubulars (and Vittoria's bizarre pressure recommendations for their top end clincher tyre) is causing people to pause and think on tubulars a bit, certainly not the death of them yet but it's interesting watching the industry shift around in terms of tech development. As a wheel brand we have to follow the tyres to varying degrees in terms of our own development, but fortunately the new Corsa Pro Speed is an absolute banger aero & Crr wise on our best wheel (Titan) so happy days!

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AeroCoach UK
http://www.aero-coach.co.uk

n=1, and I'm a roadie. But even when I used tubes, I used a backup wheelset for this purpose. If race morning has surprise wind or is super wet, I just go to the shallower front wheel, and grippier tires on the other wheelset.

Because even changing out latex-tubed tires on race morning in a downpour is a stress I just don't want.

For those who can afford it, I recommend the backup wheelset for all triathletes and roadies. You never know when you're going to roll over the 3-inch nail that penetrates the wheel rim while riding your bike to the T2 setup 15 minutes before the swim start. For me this backup wheelset is usually my training wheelset, e.g. the new go-to daily wheelset similar to the Zipp 404 cohort that is pretty dang aero and fast in its own right, so it's not like you're throwing in the towel by going to the backup.

it's nice to know i didn't make a fool out of myself ;-)

but i need to ask. i completely understand the conti 5000 TT counsel and i think you saw that over the last year or two in the pro ranks of triathlon. almost every pro who could get hold of that tire (the year it came out) did in kona, and there was a lot of tire changing by matt hill (fredly here on the forum) to that tire for every pro coming in to have their HED wheels tuned and looked over for the race. but... based on your test, this phrase from above: "we tend to recommend GP5000 (or in good scenarios GP5000 TT) for triathlon customers." does that remain true in those cases you'd recommend the 5000 TT?

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Dan Empfield
aka Slowman

1000% agree.

This sentence is what made me ask the question

"This allows us to calculate what is known as the Coefficient of Rolling Resistance (or "Crr"), which can be used to model the power output required to travel on a normal road"

Can you explain this : Why Gp5000TT for bad surfaces ?

Ah I see, sorry for the confusion - that sentence is just explaining the use of a Crr value in general, in a modelling situation.

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AeroCoach UK
http://www.aero-coach.co.uk

I've found it's got better puncture protection than the top end Vittoria/Veloflex/Michelin so is a safer (but still fast) choice on broken surfaces

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AeroCoach UK
http://www.aero-coach.co.uk

Yeah, if it was me doing triathlon I'd run GP5000 TT - I trained on them for a while on the TT bike to see what they'd be like in extended use - but I know a lot of triathlon customers do much bigger miles, train on their race wheels and leave their tyres on for training/racing in all conditions and so that's when the standard 5000 is likely a better all round idea. For race day only wheels 5000 TT is great

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AeroCoach UK
http://www.aero-coach.co.uk

Thanks

When comparing the 24 to the 26 how do you pick tire pressure for each in your tests ? The optimal pressure for one won't be the optimal for the other.

In this scenario we use 90psi for all the tyres on that chart - that's why you don't see 28mm+ tyres on the graph yet (only up to 26mm) as we want to ensure we get the correct pressures for the wider stuff and can explain it correctly to people reading it. We don't recommend putting 90psi into everything in the real world, but it's instead used as a standardisation tool for testing within those width parameters. Absolute minefield adjusting the pressures for different casing tensions or tyre widths because nothing measures what it says on the sidewalls and different tyres have different properties at different pressures (as you can see from our track Crr data).

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AeroCoach UK
http://www.aero-coach.co.uk

Again, makes perfect sense

I spent the week last week testing tire pressures. Of course if you put a 28mm tire at one pressure and the 30mm tire at the same pressure, they will test differently. But if you put both tires at their optimal pressure, not so. And yes, finding optimal pressure is a lot of fun. But we did well.

People will look at your chart and say "26mm rolls better", which is not necessarily true

You are being quoted on another forum as saying you will race with 24 rather than 26. I suspect you are layering on the aero component of the tire. Makes sense.

I guess what I am getting at is their a belief that wider is overall faster and people should make sure that is true for them.

Yes, definitely - I do also feel as though people think this is the case and if you take the overall package it isn't always the case is it!

I feel a lot of the problem (if it's a problem?) is that consumers are being told that wider is better and better for everything, and the increasing widths of the offerings from the larger companies inherently suggest so.

Personally, on our super deep (100mm) top end wheel, which is 26.7mm at the brake track and >30mm wide at the widest point further down, a 24mm Corsa Pro Speed is a real winner from both aero and Crr. We were in the wind tunnel yesterday testing it - I want to do a bit more data at the track too which gets the combined difference - on our shallower wheel (78mm depth, 26.7mm brake track, >31mm at widest point) I suspect the 26mm Corsa Pro Speed will be a better choice as we know that 78mm wheel and its rim shape can "absorb" big changes in tyre shape and width without as much of an aero penalty as the 100mm wheel, but more data required there.

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AeroCoach UK
http://www.aero-coach.co.uk

the one thing i would do, for a big race, is change my tires, that is, put on a new set of tires and/or in any case ride tires with fewer than 100 miles on them. my instinct tells me that a tire that hasn't had the contact patch flattened out by tire wear is faster. but you would not much better than i would.

the one "race" tire that i put quite a bit of miles on in training, with good results so far (no flats) is the goodyear F1 supersport.

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Dan Empfield
aka Slowman

While still on tubulars for racing...I have swapped out my race wheels annually whether they looked "fine" after 6-8 races a year, or not. It can be pricey as I have been on Specialized Turbo Cotton S-Works "All Rounder" lately--but I have never flatted in a race while on the bike once I started swapping them out annually...so maybe 30 years or so? Last flat was at Wildflower one year and it was a Conti GP19. Definitely want nice new tires for the bigger races.

What about Schwalbe Pro 1? Any feedback on those? I have a set I haven't used at all yet which are on the new ride--are they dogs or not, or just not in the same time zone as a Conti 5000 TT or Vitorria Pro Speed?

i have a lot of miles on that tire, and it's a great, great tire. i would not hesitate to race that tire in a 70.3 or longer because i hate flats, and that tire doesn't flat. it's kind of like the corso pro in that it's unlikely to flat and pretty fast for a no-flat tire.

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Dan Empfield
aka Slowman

n=1, but I have never had more sidewall cuts than in my Pro One era. Doesn't justify the slightly sub-par Crr for me given the poor puncture resistance.

i think this is a large part of why we get conflicting reports on puncture resistance. i've not use the pro one but comparing the corsa pro and gp5k its clear that the difference is in the sidewall - gp5k has tougher sidewalls so more protection there but also why it is often said to have bad "feel". tread protection on the corsa pro is as good if not better than the gp5k so the practical experience will depend on what sort of hazards your roads contain - smaller stuff that primarily hits the tread or bigger things that stick up into the sidewall.

I got a bunch of pro ones on discount, didn't end up being any cheaper because I went through those tires faster than any other tire I've used. Especially given they're not specifically TT tires, I was super disappointed with those, and they're not particularly fast either.

True. Another factor in the latex vs. tubeless argument is related. For bigger tires, 28mm and up - the pressures used increase the chance that you pinch your sidewall on the rim. And I don't care what people in this forum claim, I learned the hard way that latex *will* pinch flat just fine. The reason I went to tubeless very early was the TomA/Josh@Silca data suggesting that I should run real-world pressures around 80PSI. My latex pinch flat frequency went through the roof at around that 80PSI.

I am not sure I have ever pinch-flatted tubeless, though it's possible.

Edit: I have pinch flatted tubeless, but it was a pothole strike so brutal it destroyed my carbon rim.

i hit a deep, square pothole at 45km/h, destroyed both rims but both tubeless tyres (gp5k) were still at rideable pressures, i think there was some air loss but not much. not that i really wanted to ride on with big cracks in the rims! i did put new tyres on the new rims when i go them too - old tyres looked fine but i didn't want to risk it

i think this is just due to where you ride and where i ride (tho i did sneak into your neck o' the woods a few months ago for a foothill / emigrant trail / diamond valley loop). my "problem" is that i have not had a flat, of any sort, riding tubeless, road or gravel, in 5 years. (and i used to get my fair share of flats on the road). incidentally, i began riding road tubeless 5 years ago. i have yet to have my first flat riding road tubeless. in particular, i guess i just don't experience sidewall cuts. i try not to ride through fields of razor blades. that must be it.

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Dan Empfield
aka Slowman

Not if the Corsa Pro Speed has similar puncture performance as the prior G 2.0 Corsa Speed (which, while much better than the first gen Corsa Speed, was OK but certainly not great). If that is indeed the case, then these are the tires I would consider, ranked from "Safest" to "Living on a Prayer":

• Training: GP5000S TR
• Racing/KOM hunting: GP 5000 TT
• Long course tri: GP 5000S TR (bad roads), GP 5000 TT (nice roads)
• Short course tri: GP 5000 TT (conservative choice), Corsa Pro Speed (more aggressive choice)
• TT: Same as short course tri, but add in the Veloflex Record for the Icarus option

Disclaimer: I don't actually participate in triathalons, but these are the tires I would choose if I did

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Amateur recreational hobbyist cyclist
https://www.strava.com/athletes/337152
https://vimeo.com/user11846099

Great tyre on dry roads, but I found it always felt sketchy on damp and greasy or wet roads. This feeling was backed up by quantitative measurements on https://www.bicyclerollingresistance.com/. TT version was a PITA to set up tubeless, while standard version relatively easy. Personally I do not see any reason to favour the Pro 1 over the GP 5000 or new Corsa. Last year, I exclusively ran the GP 5000 TT TR setup tubeless for road racing (Alpine gran fondos and cyclosportives) and training, and it was amazing...