I've been riding Compass tires for years - I currently have the 700 32s, 35s, 38s, and the 650b 42s, and 48s. My poorly calibrated feeling meter also says they roll fast. All the versions I have are the 'Extra Lite' casing. I know Jan has done some testing, but it would be interesting to see someone who is independent get some data. Tom, I'd be really interested in your results.

It's amazing the kind of terrain I've taken the 650b 48s on - I've bombed down some crazy stuff. A major weakness is mud though - no tread is lethal.

---

_______________________________________________

"Regarding the Corsa Speed I was going by your response in Post 90 of this thread:"

forgot about that. but if you add the 2w you get by putting a latex tube in standard tires, it still slays everything. doesn't it?

"You are wondering why no more love for three candidates - Spec TC, Michelin Power Competition and Vittoria Corsa Speed Open TLR, over the Conti offerings?"

i simply don't think there is a category in cycling where one model of one brand has this kind of stranglehold on the market without having a product that is so much better than the rest of the market. giro i would say except it only has half the market share (of slowtwitchers) that conti has.

"Even if we follow the BRR testing rankings, there are two Conti offerings on the list that are equally fast or faster than the Michelin. Plus the Supersonic."

fine. why aren't these selling? in the case of the best roller among them i think it's a puncture resistance issue. but i agree with you. do you think the 4000S II should be outselling the attack, the supersonic, the force by as much as it is? does it deserve that kind of market share just out of the models conti sells?

"I still believe it would be very informative to ST users and cyclists interested in performance to have a ST tire shootout."

well, i'm kind of circling that idea right now. i don't know for sure yet what it would look like. i don't care what tires you buy. i just want you to think about it before you make your decision. as with wetsuits, bikes, the races you decide to enter.

---

Dan Empfield
aka Slowman

No. I don't think we have the data to confirm that yet. Just going with the tube change I would say the GP SS, GP TT and TC all are the equivalent or possibly even faster. I'm not ready to commit to tubeless road yet and wouldn't want to deal with mounting a tubeless tire with a latex tube. So if I can get equivalent of better performance from proven tires I'm not changing.

I also have a storied history with Vittoria tires (and their Zipp derivatives), but I've avoided presenting this as an issue because I don't have lots of data. My experiences have found them fragile. Someone else mentioned cutting down one of their Corsa Speeds sidewall to sidewall. I have this happen with two of their older Open Corsas myself. Sure it is on me, as always, for hitting something. But when you experience a tire failure that isn't just a flat, but an outright ride-ender then one (at least me) are less inclined to make this their go-to tire product.

This is coming from someone that regularly flats on the GP4000S/SII. I'm not going to give fanboi testimonials about never getting flats. My experience is the opposite. I ride the majority of my miles in two states, and in both of them there is a lot of debris on the shoulders and a lot of rumble strips along the highways. This expands the potential for running over debris. Most of my flats come from hitting rocks of some type. I'm pinched on the shoulder by cars, going fast, and there you go. I can count on one hand the recent flats I remember on my GP4000S/SII that aren't nicks or cuts to the sidewall from rocks on the shoulder or sharp debris in a rumble strip or pavement gouge. My routine now is to superglue a strip of gorilla tape over the nick later and keep running the tire as long as the tread is good. The only tread puncture flats I see are kiawe thorns in Hawaii and those little pieces of steel belt wire that come from truck tire explosions.

These flat experiences are mainly why I've become more comfortable with using the GP SS as a race tire. Race courses generally allow me to ride in the road lane and I almost completely control my flat situation by not running over debris:)


I generally agree here. At least with respect to the GP4000SII. I think the tire's following has grown over the last several years in large part to word of mouth through forums such as ST. Since it took some time for this to occur, I would assume it will take quite a while for any other tire to make a dent (there might be parallels here to Cervelo Tri/TT bicycles). The Spec TC could be that tire, but for some of the things I mention earlier. The price probably most of the issue. I can't believe what I see done in the tri and cycling world to save a buck when bikes cost 4 and 5 figures. Human nature to save a buck I guess.


No I don't think it should outsell the other Conti offerings. Given some time I think these other Conti offerings will become more popular and could even expand Conti's market share. They are much less used than the 4000SII because they aren't as well known or as available. The Attack/Force III have just been released and are labeled 23/25 instead of 22/24. I haven't seen them measured for actual width changes or tested for Crr. They might become the new go-to combo of Crr/Aero. The GP TT is a strange one. Not a lot of testing. It sure seems to roll well, but it "looks" wide. Maybe it will become the Conti version of the Spec TC - Crr so low that it overcomes aero sins? I agree with you that the GP SS will probably never get a huge following because of the puncture resistance worry.

When you move on to the next poll it would be informative to report the combined results of the tire polls in a post in this thread tallying the Conti offerings by model against the counts from the brand count of other tire brands in the original poll. How many Conti offerings besides the GP4000SII outsell the other brands outright?


That would be great. I think the interest here and elsewhere would be huge.

This is ST. We can go on and on thinking about tires:)

"I don't think we have the data to confirm that yet."

what is it you're looking for? i think i know what's missing from bicyclerollingresistance but it's not much (the force of the weight of the rider not entirely congruent with the imperfections in the road). still, that protocol is pretty close to as good as you can get in the industry.

"Just going with the tube change I would say the GP SS, GP TT and TC all are the equivalent or possibly even faster."

i'm willing to accept your opinion, but i think it's also fair to acknowledge that any assertion i make is just a dispassionate reporting of the data. i don't know that any data exists to support your position.

---

Dan Empfield
aka Slowman

From BRR I would be looking for:

1) test these tires in their fastest configuration - using latex tubes;
2) test a GP SS in 23c. Probably too much to hope for, but test both the pre-2017 GP SS and the 2017 GP SS:) My bet is no one is giving up one of their older GP SS's before there is testing info for the new version.

If Tom A had an opportunity (access to tires and the time available) to the test the GP TT, it would provide two common, top ranked, data points between his ongoing list of results and the BRR data (Spec TC and GPTT).


That's fair. I gave you my logic for not considering a tubeless tire outside of the Crr data results. There was also a time when I found the fastest clincher below the top performing tubulars on Al Morrison's Crr list and called it good enough!

"1) test these tires in their fastest configuration - using latex tubes"

fine. but you're asking those guys to double the testing they do for the 1 percent of users who'll use a latex tube. the alternative is you can take BRR's word for what the delta is, on average, between butyl and latex (i have a question into jarno on tubes, waiting for an answer, how does he choose the butyl tube for each test and what is the delta between various butyl tubes; i'll report back when i get the answer).

one thing of interest: they did test 4000S II with and without latex tube, and in the fastest config the difference was 1.6w. now, i'll agree that's 2w at the speed you'll race at. and that's 4w for the pair. but that 1.6w doesn't overcome the difference between a tubeless that is 2w or 3w or 4w faster than a standard tire, at least in THIS testing.

---

Dan Empfield
aka Slowman

I'll chime in.
I use Conti GP4000 2 with latex tubes on both my road going bikes.
If I were to setup a TT bike tomorrow, I would use them and recommend to others that I set up to also use them.

Reasons:
They are as close to the fastests to not give a dam.
I haven't had a single flat that wasn't a small rock tearing the sidewall open and bad enough that any tire would have failed in the same situation.
They are cheap online and shops around here simply match the online price.
All non 'one brand' shops stock them in whatever size you like.
They corner well in both wet and dry and give good tactile feel as to how much grip is left, the 25mm versions especially so.
They have decent tread life.
They mount up without levers on every rim I have tried.

My only complaint is that the single direction arrow is bloody hard to find.

Until I find a tyre that matches that, I'll keep using them.

Interested to try the new Michelin, but they cost more and I still have a few conti's kicking around. Mainly want to try them as they look like they may be as good as the conti but run a little narrower so I have better rear stay clearance.

Vittoria tyres have proven too delicate for myself and many others so waiting for others to get burned before I waste money on them.

My trick for these is to always mount them so that viewing the tread at the top of the wheel has the "shark fin" shape pointing the proper direction. Not sure how to put the visual description in a clean sentence so hopefully that makes sense. I don't think my eyes are good enough anymore to find the arrows:(

Almost everyone, including myself, is highlighting flat protection. Once you discount that then floating around among other manufacturers for 1-4w of saving (3-12 seconds over 40km) makes a little sense.

Most of us would rather not fluff about on the side of the road going absolutely nowhere during a race - it's like going 1x before narrow-wide was introduced.

---

'It never gets easier, you just get crazier.'

Another interesting point is that almost half the UCI WorldTour peloton ride Continental - I count 8/18 teams here. About half of the remainder sport Corsas, and the rest are on their sponsored rubber (Specialized riding Specialized, etc).

https://cyclingtips.com/...-the-2017-worldtour/

Obviously these Contis are not 4000s2's, but we don't have team cars, neutral support, and a team to pull us back to the bunch. Our list of priorities has to be slightly different.

---

'It never gets easier, you just get crazier.'

yeah, for most people that sort of time saving is insignificant, whereas even with a quick change a puncture is a significant time loss, not to mention it can mentally destroy you.

so something like a supersonic is not really a good trade-off for most of us. a GP TT or turbo cotton maybe as they have reasonable puncture protection still (8/9 vs 11 for GP4K according to BBR, contrast to 18 for a gatorskin). its not really clear how much is enough under "normal" circumstances so whether those extra 2 puncture protection points are meaningful. i certainly believe that there comes a point at which anything that will go through a good puncture protection will go through virtually any tire, a lot of us have found from experience that the GP4K is about that level

the GP4K is known to save you some time thanks to its aero shape so it has that upside to counter its modest CRR. for the not so fast, that high-yaw performance is significant

I didn't think it would happen this quickly, but I had a chance to put the GI kit I pictured above through its paces this morning. We've been having a bunch of rain lately, and today was the one day this weekend were a relatively dry ride was possible...roads were wet though. On the ride, I got a puncture in the rear Compass 26"X1.8" tire I'm running tubeless. It wasn't a big hole, only ~1mm, but the wetness was preventing the sealant from "coagulating". So, I stopped and pulled out the kit, prepared a cord in the tool, stuck it into the hole (sort of hard since it was a small hole) until a small amount of the ends stuck out, gave the tool a small twist and pulled it out. I had packed a small knife, and cut the exposed ends flush at the tread. The leaking stopped immediately. I gave the wheel a spin to get some sealant there, topped off the tire, and was on my way in ~5 minutes. Rode another ~40 miles on it after that and by the time I got home, the repair is barely noticeable.

I'm flabbergasted this puncture repair isn't mentioned more when discussing road tubeless. It's a game-changer for me...if and when we finally get TLR tires that roll as fast as the best clincher/latex setups. This was easier than changing a tube in a clincher.

Granted, I was only running ~50 psi in those tires since they're so wide, but between this and my DIY plug in the 26C S-Works Turbo Tubeless I did, I'm basically sold on the technique.

---

http://bikeblather.blogspot.com/

I want to point out that across multiple road tires I've roller tested first with a latex tube and then set up tubeless, there is NO difference in the power it takes (i.e. much less than 1W difference for a pair, if any) at road pressures

I'm actually not sure where the guy who runs BRR gets that number from...he has a test up there on MTB setups that shows a difference between a tire with a latex tube and set up tubeless at very LOW pressures, but that difference lessens as pressure rises, and is completely gone at 50-55psi.
http://www.bicyclerollingresistance.com/...ss-latex-butyl-tubes

In other words, his own data doesn't match that statement.

He also has a road tire test comparing a clincher Schwalbe tire with butyl, light butyl, and latex tubes, but then compares those to the tubeless version of that same tire. The tubeless doesn't fair well comparatively. But, that's not really the comparison we're talking about...
http://www.bicyclerollingresistance.com/...ne-tubeless-clincher

Anyway...like I said, I wouldn't take that "latex tube hit" as reality.

Lastly, I have a pair of Corsa Speed TLRs on the way to me right now. I'll definitely be roller testing it soon (both with a latex tube and tubeless) and well soon see how it ranks on my chart :-)

---

http://bikeblather.blogspot.com/

Run tubeless or with latex?

Edit: just saw you said butyl later on. yikes.

Is it fair to say that Flo is ahead of the game in their testing?

As a Flo user, I have access to good information that gives me confidence in my tire choice (GP4k2/Force):
http://flocycling.com/aero_tire_power.php

I found the recent white paper from Specialiized just as compelling for Roval users. Perhaps other manufacturers will follow suit as we pursue integration for the next phase of aero gains?

Scott

Well, 26x1.8 is MTB-sized and not far from MTB pressure - not surprising that it worked. I've plugged quite a few tyres this way (not my own, thankfully). I just never thought it's viable for a road setup, which I guess from your DIY repair sounds like it is an option.

For my training tyre, if something like the Bontrager AW3 comes out in a TLR version I'm probably sold. My race wheels aren't tubeless-ready rims, though.

---

ZONE3 - We Last Longer

"Is it fair to say that Flo is ahead of the game in their testing?"

i don't know. but i'd say that wheel makers who don't give tire advice, with data to support it, are missing a pretty inexpensive opportunity to do some real good for their customers.

while the internet has turned a bunch of average people into self-proclaimed experts, when it really comes down to it people don't want freedom and choice about things they know, in their hearts, they know nothing about. they want to be told what to do.

---

Dan Empfield
aka Slowman

So, with all the information we now have which tyre is now the fastest choice?

Is it the 'new' supersonic?
are we still sticking with the gp4000?

What about the new Michelin and Vittoria tyres that have emerged in the past year?

Or are we going with the low rolling resistance of the turbo cotton, although overall when aero and RR are considered the supersonic still wins.

I have a set of 23mm supersonics on my firecrest that are currently still keeping their place.

You also have the original work I published at A&M regarding tire aerodynamics. I then followed up on the topic more in depth in 2010:


http://biketechreview.com/...trispoke-tire-choice


http://biketechreview.com/...458-1080-tire-choice

I think there is opportunity for someone to make a well-shaped, narrow, low rolling resistance tire.

---

=================
Kraig Willett
http://www.biketechreview.com - check out our reduced report pricing
=================

The fastest tire is also the one that doesn't flat. Otherwise, I'm investigating this right now. There is a lack of ready answers when I ask companies that make tires and wheels. That's unfortunate. So I think we need to make a cheat sheet.

---

Dan Empfield
aka Slowman

Not always. Depending on the distance, especially long course Tri, "flat aversion" can easily result in one choosing a tire to race on that is slower than a much faster option, even after accounting for the time needed to repair a flat (if it happens).

You might recall us doing that calculus for Tom Demerly a bunch of years ago...

---

http://bikeblather.blogspot.com/

I get your point but I think you're wrong.

The fastest tyre is the fastest tyre, aero plus Carr on the appropriate wheel.

Obviously puncture resistance is a factor, but it does not make a tyre faster or slower.

Case -
I have ridden to work on my supersonic and GP4000, the gp has punctured twice, the supersonic never. The key is the puncture that took down the gp would have done the same in the supersonic, neither is faster or slower on thus basis.

Personally I don't believe that the extra protection does very much.

I have recorded the last 10 punctures I had, and they were all caused by the same 2 stage event.

Small cut in tyre, small needle of glass eventuallg gets in, puncture.

This may be more likely with an SS as it's thinner, but ANY well worn tyre with little cuts in will do the same.

So IF you use a newish tyre, without cuts you dramatically reduce puncture risk, also filling the little ones with superglue helps.

Using this methodology I have yet to puncture an SS, this will of course now happen

Good to hear from Kraig. The problem with these older tests, is they deal with the old, narrow rims. I think we all agree that narrow tires are going to work on narrow rims. What works on the newer, wider rims is a different question.

As others have mentioned above, we have really different requirements here. I, for example, do fairly short TTs, where I expect to average nearly 30mph. 10+ yaw is generally not something I expect. An AG Ironman competitor is fairly likely to go 20 mph through the lava fields with a 20mph crosswind. He needs to plan for yaw. So our tire choice good be very different.

---

My latest book: "Out of the Melting Pot, Into the Fire" is on sale on Amazon and at other online and local booksellers

Obviously there is no choice that will always in retrospect be right. I doubt there's much space between us. I never rode track tubulars in long distance triathlons in the 80s. But I did ride 240g cotton and silk tubies. A happy medium.

---

Dan Empfield
aka Slowman

the fastest tire is the one closest to the best CRR/CDA combo (on your wheels) that doesn't flat. the question is what is sufficient to not flat. maybe a supersonic will get you round safely, maybe a TT with vectran will be required, maybe the thicker tread of the GP4K, maybe a gatorskin (though probably not).

obviously it depends on road surface, debris, luck and attention to dodging debris. however i think we are missing anything better than anecdotal evidence as to what is "sufficient for typical circumstances". BRR gives us a puncture protection score, but there is nothing to say what those scores mean in the real world. this is what i would really like to see to add to the CRR and CDA tests