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Posted: Sun Oct 19, 2008 8:48 pm
by Amadeus
Hi theremery

First of all I have too say, that I respect your finding and feelings about the tyres suppleness. It is just that I have had a complete different experience then you have had.

Secondly I am assuming you are talking about the Continental 4000s clincher on just 110TPI and the Vittoria Open Corsa Evo CX “Open tubular” in 320TPI and not the tubular versions. I also assume that you tested both in 23mm wide version (which are both actually not 23mm wide! More on this further in this post). You probably know that the Vittoria is also available in the narrower 20mm version.

Furthermore I have to admit that I have almost zero experience with the Vittoria Open Corsa Evo CX (Just 250km on a pair of very experimental wheels). But I have tried all the 290TPI road race versions thoroughly. These 290TPI versions are made of the same material called “Corespun”, but in less fine threads that are building up the fabric of the tyre casing.

So just from logical point of view, I recon that this Vittoria Open Corsa Evo CX that is an “Open Tubular” that is on 320TPI should be even a little suppler then the 290TPI versions.

Therefore I have to say that in general I am very very surprised by your findings, but at least your latest post does clear it from one point (at least for me it does).

In the contrary to your personal experience and findings, I did find the Vittoria Open Tubulars (the 290TPI versions) much more comfortable then the Continental 4000s clinchers (which is in line with the expectations based on the theory that more threads per inch means a suppler tyre casing). Tyre pressure is a crucial aspect to this.

My thoughts are that this difference in experience is or could be due to your method of comparing these tyres.

In my opinion it is far from correct to make a comparison between two different tyres on the same tyre pressure. This idea of comparing tyres on the same tyre pressure may seem a logical approach at first, but in fact this is a complete wrong approach (but this is a common mistake made by a lot of people even “TOUR magazine” makes the same mistake).

I will explain why it is wrong to compare different tyres on the same pressure.

Both of the tyres that we are talking about carry the label 23mm wide. But are they? No! In fact they are not. In fact the Continental 4000s clincher is less wide actually I measured 22,4mm (I even measured a few on 22,0mm) and the Vittoria is a bit wider then 23mm actually I did measure 23,8mm (up to 24,2mm).

So actually I did measure an average difference of 1,4mm (!!!!!!!) in tyre wideness between the Vittoria Corsa Evo series in 290TPI and the Continental 4000s! (I do assume that the 320TPI are also wider then 23mm).

As we all know a wider tyre should be ridden on a less high tyre pressure then a narrower tyre.

In my opinion 1mm of difference in tyre wideness should be about 0,5bar in pressure difference (to come to this figure I did take 8bar tyre pressure as average starting point).

So if you would like to compare the Continental 4000s which (probably) is an average 1,4mm narrower then the Vittoria Open Corsa Evo CX you should ride the Vittoria’s on 0,7bar less then the Continental, and certainly not on the same pressure.

I would say try it! And let me know your findings!

If you have more questions to this approach feel free to ask!

I like to share our thoughts about this issue.

I actually do believe that Continental is making the tyre less wide to keep the tyre on an expectable weight. The Continental 4000s weigh 225gram!! Which is about 25 to 35 grams more then the competition weigh (Schwalbe Ultremo & Michelin Pro3Race).

Posted: Sun Oct 19, 2008 8:48 pm
by Weenie

Posted: Mon Oct 20, 2008 3:27 am
by fdegrove
Amadeus wrote:I agree with Fdegrove about storing the tubulars or so called "open Tubulars" for a while. The puncture resistance is much better after a few months (we all know that self esteemed tyre professor Jobst Brandt does not agree here).

@Fdegrove; to answer your earlier question. "What is the difference between Clincher and open tubular"?

An open Tubular is a not sewn up tubular of at least 200tpi and up to 330tpi (Veloflex, Challenge Criterium, Deda Tre are 300TPI Vittoria is 290TPI exact like their tubulars). Open tubular tyres are made by brands/producers of tubular tyres. Basically open tubulars are build up exact the same way as tubulars and therefore realise almost the same riding qualities. As you know very well higher TPI makes a better Rolling and suppler tyre (less RR).

The difference in Clincher and open tubular is mainly their TPI and the compound used in between the threads of the fabric).

The best clinchers available are up to 127 TPI in one layer of fabric (like Schwalbe Ultremo/Michelin Pro3Race). Continental leis about this, due to marketing purpose. Actually Continental says that their 110 TPI Conti 4000s clincher is 330TPI. But Continental counts all three layers of fabric instead of one!.

The last ten years clinchers of lower TPI are trying to close the gap to Tubular and open Tubular. Actually they are getting closer. Even with a lower TPI ride quality is getting better in “clincher country”. This is due to a lot of research that is done for instance in the use of "compound" that keeps the threads in de fabric together. Due to a more flexible "compound" in between the threads the clinchers are getting better and better.

But Tubulars and open Tubulars are still providing the best riding quality.
On the contrary clinchers provide the best puncture resistance.
High TPI makes a tyre more prone to puncturing but suppler.
Lower TPI makes a tyre more resistant to puncture but harsher.

One of the guys in this thread said he experienced that Vittoria at 290tpi gave him a harsher ride then a Continental at 110tpi that made me smile because that really is not possible. I have on both and riding quality of the Vittoria is far better but it is comparing two different worlds.


This page is going to be filled to the nook but bear with me.


I don't recall exactly what Jobst Brandt had to say about storing tubulars or open tubulars for that matter but I do recall his reply as follows: vendors want to shift their wear as fast as possible and tyres don't get any better from being stores in shops. I agree, no compound used in tyres actually improves form being exposed to UV rays and whatever hangs around in the air.
I don't think either that all tyres actually benefit from storage, some do some don't and at best some just don't change at all.

The ones that do however are made the old-fashioned way using glues and non-vulcanized rubbers.
Through proper storage the solvents in the glue have time to outgass, the natural rubber hardens a bit.
The latter may be cause for reduced CRR but nothing dramatic I'd think. The hardened rubber may well improve puncture resistance but I doubt it's that simple.

The argument you bring to the table being that less supple tyres are more puncture prone is also not quite correct for less supple tyres usually are thicker and heavier.
It may well be the extra thickness that makes it harder to puncture them as a more supple tyre complies more to a sharp object analogous to the fact that a latex balloon is harder to puncture than a butyl one.
IOW words supple material conforms around an object whereas less supple material is more easily pierced.
Overinflate the most supple of your fav open tubulars and it won't last too long before it goes pssshhhh.......
However what is deflecting most are the sidewalls (excluding narrow tyres in the 19-20m width which can't but deflect along their radius, see the contact patch as a stand-out witness) and that's why you'd want a wider tyre when the going gets tough. Better traction, more comfort too. (Paris-Roubaix being a prime example).

The definition you bring of what an open tubular is is basically correct but it has nothing to do with thread count as such. Strictly speaking any tubular could serve as a model and OTOH any clincher manufacturer could also make an open tubular.
Traditionally an open tubular is a tubular that's not sewn up but has instead been outfitted with a bead so it can serve on a clincher rim and that's the end of that.
As said, any clincher-only manufacturer can do that just the same even without a tubular donor.
No, what sets them apart from your run off the mill clincher are the rubber compounds used, the high tpi count and their pedigree. I.e. derived from our xyz tubular model that has inherently all the goods we've come to appreciate: real rubber, natural fine coton spuns, handmade by passionate workers and an addictive smell of fresh glue. You get the picture.
And that's why I asked you that question, what sets an open tubular apart from a clincher?

Ask yourself, are Schwalbe Ultremo clincher tyres Open Tubulars because there's also a tubular around carrying the same name or is the tubular version just that, a tubular version of a clincher.
How about the tubular version of original Conti clinchers. What are those, tubular clinchers? They are, aren't they?
And ride like it too.
So strictly speaking nothing much to warrant an open tubular to outperform a clincher other than the mere fact that no manufacturer in his right mind would offer an open tubular version of their el cheapo tubular I suppose.
Some offer a tubular version of their clinchers, Ritchey is one example but it remains a chicken egg guesswork and I don't think it turns the Ritchey clincher into an open tubular overnight either.
That in turn makes your statement about clinchers offering better puncture resistance a bit suspect also to say the least.
Continental to name but one, could state that there's no reason whatsoever why their clinchers should less prone to puncture than their same tubular model.
On paper tubulars should be at least not so vulnerable to snake bites as clinchers, ones with latex inner tubes should even be more protected.

Ideally we could imagine a tyre (clincher, open tubular or tubular alike) as supple as the best silk tubular with a well designed liquid crystal PRB such as Vectran, a thread similar Conti's Black Chili compound. Now if somehow we could protect the sidewall from cuts without loosing its suppleness that would be quite some tyre for our climate, wouldn't it?
Sure enough there's Jevelot, or if you hate Tufo Sealant on the inside of your gear as I do you can use that too, Aquaseal, Aquasure you name that will all help in their specific way but nothing as effictive as keeping your tyres clean and expecting them carefully for any slits and cuts before you hit the road.
An occasional wipe down with a vinegar soaked cloth also seem to help for non-vulcanized natural rubber tyres too.

As it stands I ride Veloflex Carbon during the few drier periods of the year and Conti's clinchular tubbies for when roads get just too slippery.
It's a compromise I can live with.

Oh, any development in clincher country worth its salt can surely be engineered into tubulars and open tubulars and "the gap" would still be there or won't it?

Ciao, :wink:

PS. How about that Duvel?

Posted: Wed Feb 18, 2009 12:27 pm
by 2 wheels
John979 wrote:Continental posted the article in English here: ... 00s_en.pdf

Not that it is going to change anyone's mind...

The above test is Tour's tire test from 09/0027.

Tour carried out yet a new clincher test in 8/2008:
Download this article here (in German): ... 808_de.pdf
This test contains the following clinchers:
Continental GP 4000 S
Continental Grand Prix
Hutchinson Intensive
Kenda Konstrictor
Maxxis Courchevel
Michelin Pro3 Race
Michelin Krylion Carbon
Specialized All Conditions S-Works
Vredestein Fortezza TriComp

Posted: Thu Feb 19, 2009 2:53 am
by robnfl
Darn, I wish I could read German....


Posted: Thu Feb 19, 2009 6:07 am
by theremery
I've given up on the magazine's tests now. I suspect different pressures and surfaces make the whole testing process a pretty difficult one.
I've found the that AFM tire testing review8 PDF mirrors my own experience for how I use tyres on our local surfaces here (and agree with Amadeaus that the pressure set-ups are absolutely critical) so closely that it has proven to be a very useful predictor of tyre performance (and that is really what I want from a tyre review) SOOOOOOO well that I use it exclusively now. There is a link to it somewhere in this thread, I think.

Posted: Thu Feb 19, 2009 7:57 am
by djconnel
You don't need to understand a word of German to interpret the figure on page 40.

Continental 4000S "wins". Additionally, Latex is much better than butyl, lightweight butyl is better than heavy (but heavy latex is still better than lightweight butyl), higher pressure has less rolling resistance than lower pressure, and the Continental also cornered faster than the other tires. The cornering test is of uncertain precision or accuracy, but rolling resistance tests seem fairly straightforward.

Curiously, the Contental 4000S did not do well in the BikeTechReview rolling resistance test.

Posted: Thu Feb 19, 2009 8:08 am
by rruff
djconnel wrote:Curiously, the Contental 4000S did not do well in the BikeTechReview rolling resistance test.

That isn't how I read it. It was on par with the Pro3 and all the tires that performed better are known to have poor puncture protection and durability.

Posted: Thu Feb 19, 2009 12:44 pm
by djconnel
In the test, the Continental 4000S 23 (used: 200 miles) dissipated 15.1 watts per tire with latex tube. Vittoria EVO KS (23)/Michelin Latex Tube (18/20) dissipated 13.3 watts per tire. That's a 1.8 watt difference at the test speed of 25 mph with a 100 lb rear wheel load. That's substantial. Of course, the Vittoria wasn't reported by Tour.

Second place in the Tour test was Michelin Pro 3 Race which was 4.6 watts more than the Conti. In the BikeTechReview tests, the Michelin Pro 2 Race with latex tube was 15.0 watts, 0.1 watts than the Continental 4000S. This was true for two Michelin's tested: a 23 and a 20. So BikeTech didn't see an advantage to the Continental 4000S. Or is the Pro Race 3 more resistance than the Pro Race 2?

Michelin claims the Pro Race 3 has less resistance, not more, despite better claimed grip. The Pro Race 3 is lighter, and that does often mean lower Crr.

In any case, it seems if Tour is guilty of anything, it's picking the competition so Continental comes out on top. I also don't read German so I don't have too much detail here.

Posted: Thu Feb 19, 2009 6:37 pm
by rruff
I've been riding the Conti 4000s tires since Oct. I haven't kept a strict log of miles, but the weather has been great this winter and I've been riding a lot... and I'm on the same rear tire. That is at least 2k miles... maybe 3k... which is more than I've gotten out of even a Krylion. And it looks like I probably have another ~1k miles to go. No flats... no cuts or anything else. I rode the Pro3 last summer and my opinion is that it has a short life and is relatively fragile. They do seem to ride smoother, though.

Note that I live on a gravel road and there is a section that is a 17% grade which requires a running start and a bit of wheelspin to get up, so this tends to shorten the life of rear tires.

The Vittoria tires (and the Bontragers which are made by Vittoria) and some others, have better rolling resistance but I wouldn't put them in the same league as far as lifespan and durability are concerned.

Posted: Thu Feb 19, 2009 8:31 pm
by djconnel
Sure -- for race tires, performance is key. For training tires, durability is important: what's a few watts here or there? The article suggests the Conti is a great race tire, which is inconsistent with more extensive data.

Posted: Thu Feb 19, 2009 9:10 pm
by Ypsylon
djconnel wrote:In any case, it seems if Tour is guilty of anything, it's picking the competition so Continental comes out on top. I also don't read German so I don't have too much detail here.

Let me help you out. In the text it says that Vittoria and Schwalbe refused to participate because they were about to launch a new product, but hadn't done so.

They also stress that they were looking for an all-round tire, but you're right, the data suggest the 4000s is the best for racing, out of the ones they tested.

Posted: Fri Feb 20, 2009 2:23 am
by rruff
djconnel wrote:Sure -- for race tires, performance is key. For training tires, durability is important: what's a few watts here or there? The article suggests the Conti is a great race tire, which is inconsistent with more extensive data.

Still... I wouldn't say that... if you value durability and puncture resistance, as well as cornering ability, at a small "penalty" in rolling resistance, then the GP4000S is still a very good race tire.

BTW... I sent a 20mm Conti GP SS to Al (BTR) to have him test it, and it got a Crr of 0.00251 at a weight of 134g. So if you aren't concerned about durability, that is a good choice.

Posted: Fri Feb 20, 2009 4:56 am
by theremery more than 3 watts per wheel, I wouldn't call the increase in rolling resistance that slight. To me.....the 4000s is a good all-rounder, and my most common recommendation to friends for their bikes. They grip well (REALLY well) feel smooth and roll OK but veloflex records and Vittoria evo chronos (tubs glued properly) smash them for crr (oh yes....see crr values for properly glued tubs if you still think the best crr's come from clinchers.....nope.....sorry, the top performers are all tubs). If I want to go fast and cornering is NOT an issue -I use Chrono evo 20mm on my climbers (Tub)
-I use Open corsa evo CX on my clinchers.
When doing criteriums, hill races etc....the benefits of the 4000s grip, surity and smoothness outweigh the pure speed of these vittoria tyres I go grippy, enjoy the corners and use the 4000s option.
If you guys think I'm joking about the wattage, that PDF really is worth a look. It was done with a sensible and arguably adequate attempt to control most variables (as good or better than most published tyre tests) with enough extra information to extract good info about benefits of NOT using new tyres etc (check new tyre values against older 200km tyres).

Posted: Fri Feb 20, 2009 1:19 pm
by HakanC
djconnel wrote:Or is the Pro Race 3 more resistance than the Pro Race 2?

Michelin claims the Pro Race 3 has less resistance, not more, despite better claimed grip. The Pro Race 3 is lighter, and that does often mean lower Crr.

If you compare Tours test of Pro2Race and Pro3Race ... nt/?id=193 ... 808_de.pdf

The Pro3Race seems have a higher Crr, approx ~4-5W, actually the Pro2Race Crr is very close to that of the GP4000S

This difference can ofcourse very well come from individual tire differencies or from the Crr testing machine.
The Pro2race was tested in 2005 and the Pro3race in -08


Posted: Fri Feb 20, 2009 1:19 pm
by Weenie

Posted: Fri Feb 20, 2009 3:43 pm
by djconnel
theremery more than 3 watts per wheel, I wouldn't call the increase in rolling resistance that slight....Go READ.

Agreed: Exercise for the reader: how much weight do I need to add to the bike to yield a comparable increase in required power? And would you buy the tires if they were that much heavier, but at the same rolling resistance?

Conclusion: if you trust Al Morrison's BikeTechReview measurements, then these may well be decent "all around" tires, just like steel is a good "all around" frame material.