[jhenry4]

in looking for a new set of tires i've settled on two choices from vittoria and have a few questions concerning performance and durability differences.
the 2 models in question are the open evo KX and the diamante pro. from what i can tell so far the evo KX is a 290 tpi tire with a kevlar strip beneath the tread and some kevlar mixed into the casing, while the diamante pro's are a 220 tpi tire with full rim to rim protection.
does anyone have any comparative evidence on ride quality or durability differences?
also...
what is meant by calling certain clinchers open tubulars? is this a reflection of the ride quality or construction methods?

thanks

 

[Kerry Irons]

Partial answer

also... what is meant by calling certain clinchers open tubulars? is this a reflection of the ride quality or construction methods?

I can't answer specifically about the tires you're looking at, though I can say that, IMO, people tend to WAY overthink tire choices.

The answer to your second question is simple. The term "open tubular" is a marketing phrase designed to make people think that the tire in question is somehow better than a competitor's tire, since EVERYONE knows that tubulars are better than clinchers, right?

 

[Joeslow2]

Disclaimer: Vittoria sponsors my amatuer racing team.

I have not used the Diamante but IIRC it is made similarly to the Rubino and other similar tires. When the tire is not installed on the rim it still has some "shape" to it. The Open Corsa's are flat and really dont have much shape until installed. I dont know the technical aspects but heres my take on the OC compared to other tires I use.

First off, the Open Corsa is the best riding clincher I've ridden. That comparison includes Michelin Pro Race, Pro Race2, Conti GP 4k, GP 4-season, Vittoria Rubino Pro, Zaffiro Pro. They grip well under crit racing conditions in both dry and wet weather. You can get an idea of how supple they are by handling the tire in the shop, but you really have to ride them to see the difference.

The downside, there is a strip of glued on rubber over the supple casing. Extreme forces can cause this strip to come unglued (sliding out in a dry corner at 30 mph) ruining the tire, but most other tires would be ruined under the same conditions. The rubber strip isnt very thick and locking the brakes once can wear the rubber down to the casing, again... other racing tires will do the same. At 180, I get a couple thousand miles on a rear tire, max. They are awesome racing tires, and they ride beautifully, but they just dont wear well at all. I use the less expensive and far more durable Zaffiro Pro for training and some racing (in dry weather they grip far beyond my cornering capabilites). They arent as comfy but they last a long long time. I tried the wire beaded zaffiro but found them nearly impossible to get on and off my wheels (campy, open pro and CXP 33 rims) without more tools than I want to carry with me.

 

[danl1]

I can't answer specifically about the tires you're looking at, though I can say that, IMO, people tend to WAY overthink tire choices.

The answer to your second question is simple. The term "open tubular" is a marketing phrase designed to make people think that the tire in question is somehow better than a competitor's tire, since EVERYONE knows that tubulars are better than clinchers, right?

There is a tiny bit more to it than that. Strictly speaking, there is a non-marketing terminology of "open" clincher construction. This is in contrast to "Open Tubular," which is a marketing construct. In "Open" construction, the tire is built from the inside out, by hand-gluing on each subsequent layer, tread being the last piece on. Normally constructed clinchers are made in a mold, with the tread against the mold surface, first piece on. Vittoria means it with the Open Corsas, so the Opens are made one way, the Diamantes the other.

There is an argument that because of the nature of the pressures involved, "open" construction can produce a more supple tire than molded construction. One downside is the potiential for delamination that Joeslow mentioned, and whether this construction creates a real advantage or is only the marketing hype that Kerry mentions is another discussion.

IMO, this is one of those places where life hands us tradeoffs. Diamantes will last slightly longer, Opens will ride slightly better. But you couldn't tell the difference blindfolded, and would crash if you tried. What's more, you'll never go thru enough tires to prove that there's a statistically significant difference in the tread life. My personal preference is for slicks, so I like the KS. In the Diamante, that would mean the Pro Light, and my gut says a tire that light isn't for me.

Like Kerry said, I probably overthink this.

 

[Ride-Fly]

IMHO, Vredestein Fortezza Tricomps are the way to go!!

I've used Vittoria Open Corsa and Rubino Pro, Conti GP3000, and Michelin Axial Pro and Pro Race as well as the the Vreds and my personal faves were the Open Corsas and the Vred Tricomps. Both are so similar in road feel that if it weren't for Vred's superior durability, I would rate them even. But the OCs lasted about 1500 miles before they needed replacing. They were prone to flats and cuts very easily even though it was supposed to have a kevlar layer. I never get flats and cuts on the Vreds. Even their lower tire the Fortezza SE is a great tire for training.

 

[Argentius]

I've ridden Vittoria Rubinos, Rubino Pros, Diamantes, and Open Corsas.

The Rubinos (60 TPI wire bead) rode like utter junk -- confined to the fixie.
The Rubino Pros (120 tpi kevlar bead) were what I'd call a "standard tire"
The Diamantes (220 tpi) felt nice -- noticably nicer than the rubino pro in hard cornering, more feedback, etc. More expensive, too. Reasonably good tire wear.

The Open Corsas (290 tpi, hand-sewn casing) are AWESOME. They DO feel nicer than all of the above, grouches notwithstanding. I don't think I'd pay retail for 'em... they're reserved for races or nice days that I want to have a lot of fun. They wear out FAST.

I think the Diamante is the best quality per dollar mile, or whatever. The open corsa is the best if you don't mind hurting your wallet. I've got race wheels with open corsas, and training wheels with Zaffiro pros.

Our team is Schwalbe sponsored now. I wish they made Open Corsas...

 

[Mark McM]

All tires manufacturered from inside out

There is a tiny bit more to it than that. Strictly speaking, there is a non-marketing terminology of "open" clincher construction. This is in contrast to "Open Tubular," which is a marketing construct. In "Open" construction, the tire is built from the inside out, by hand-gluing on each subsequent layer, tread being the last piece on. Normally constructed clinchers are made in a mold, with the tread against the mold surface, first piece on. Vittoria means it with the Open Corsas, so the Opens are made one way, the Diamantes the other.

I don't know where you got the idea that some tires are built from the outside in (laying the tread in the mold first), because as far as I'm aware all clincher tires are made by laying down the inner casing plys first then adding additinal plies, then any belting that may be used, and finally adding the tread. Even run-of-the-mill low end clinchers are made this way. Continental has a short animation showing this process. I never heard of any tire being manufactured "outside in" - not bicycle tires, not motorycycles tires, not automobile tires.

 

[imetis]

I've got about 500 miles on a set of Vittoria Diamante Pro Lites, and they are the smoothest ride I've ever felt. They are also crazy light and fast. After one flat, and numerous cuts on the rear tire, I pulled them to save for race days. I'm running gatorskins now, which are obviously harder and heavier, and have run zaffiro wire bead, and a cheap bontrager. None of the other tires I've tried are in the same class as the Diamante's, but I think they are an amazing race tire, just don't expect high mileage out of them. I've heard that the non-lite version are significantly more durable.

 

[danl1]

This describes auto tires, and is basically the same as the Continental animation you've provided:

http://www.goodyeartires.com/about/diversity/how_built.html

OK, so I'm responding to a internet posting and didn't feel like wasting everyone's time trying to show off how much I imagine myself to know. You are right that the components are assembled inside-out for the vast majority of tires. That gets all the bits into their proper order and place, because you can't open and close the mold for each layer.This takes us through Step 5.

Then the tires are placed into the mold, and heated to fuse the layers, belts, and tread together, mold the treads and sidewall markings, and complete the vulcanization of the rubber. This is step 6 in the process, and the mold I was speaking of, and shown very well in the animation you've provided. This is representative of the way almost all tires are made. I described it as tread being "first layer on" because the heat of the mold fuses things together from the outside of the tire inward. This forces the tire into the semi-permanent "U" cross-section that we are all familiar with.

Open-built tires proceed somewhat differently. The assembly is similar through step 5, though with slight differences - components are pre-vulcanized where possible, and the tread strip will already have it's tread embossed on it if applicable. Then (and in intermediate steps in some tires) the tires are hand vulcanized (that is, the gluing rubber holding the pre-vulcanized parts together is vulcanized) right on the building drum, without ever seeing the inside of a mold. By argument, this results in a more supple tire as the molding pressures work themselves out as the tire is made - somewhat analgous to the process of stress-relieving spokes when building a wheel. Whether you buy that it's better or merely more traditional is where the marketing fun comes in.

The difference is usually easy to spot. Conventionally made tires have the mold sprues sticking out around them like an impotent porcupine, and a telltale mold break line running around the middle of the tread. Open-built tires do not show these sprues or break lines. Some conventionally-made tires don't either, as the manufacturer takes the extra step to clean them off before shipping, but that is relatively rare. Typically, open-built tires lay and fold flatter when off the rim than conventional tires, though the gap has narrowed in recent years.

 

[Mark McM]

Open-built tires proceed somewhat differently. The assembly is similar through step 5, though with slight differences - components are pre-vulcanized where possible, and the tread strip will already have it's tread embossed on it if applicable. Then (and in intermediate steps in some tires) the tires are hand vulcanized (that is, the gluing rubber holding the pre-vulcanized parts together is vulcanized) right on the building drum, without ever seeing the inside of a mold. By argument, this results in a more supple tire as the molding pressures work themselves out as the tire is made - somewhat analgous to the process of stress-relieving spokes when building a wheel. Whether you buy that it's better or merely more traditional is where the marketing fun comes in.

That's still not enough to be able call these clincher tires "open tubulars". Many tubular tires are made by vulcanizing in a mold - does that make these tires "closed clinchers"? Of course not. The name "Open Tubular" is a just an oxymoronic marketing term made up to to try to attach some of the cache of tubular tires to certain models of clinchers.

Whether different ways of bonding/vulcanizing tires makes a performance difference is a whole other question. I suspect that by itself, it doesn't make much of a difference - there are plenty of other variables in the materials and how they are used.

 

[danl1]

That's still not enough to be able call these clincher tires "open tubulars". Many tubular tires are made by vulcanizing in a mold - does that make these tires "closed clinchers"? Of course not. The name "Open Tubular" is a just an oxymoronic marketing term made up to to try to attach some of the cache of tubular tires to certain models of clinchers.

Whether different ways of bonding/vulcanizing tires makes a performance difference is a whole other question. I suspect that by itself, it doesn't make much of a difference - there are plenty of other variables in the materials and how they are used.

...Which is exactly what my first post said.

Yep, "Open Tubular" as commonly used is mostly marketing gymcrack. There remains a valid distinction re: open construction, whether for tubulars or clinchers. That's the distinction that many miss: "Open" is a term of differentiation that can apply to both tubulars and clinchers. That is, there are tubulars made in a mold, and tubulars made via open construction, and the same is true for clinchers. It's when they start intimating "tubular that we didn't sew shut" that the marketing department has taken over.

And open construction is capable of producing a more supple tire than molded vulcanization, whether for clinchers or tubulars. Arguments can continue on and on about the relative qualities, and of course there is both handmade crap and excellent machine-made, and the other way around.

Here are other references on the topic. Apply marketing and bias filters as necessary.

http://www.torelli.com/tech/tires.shtml

http://www.bikesutra.com/ezitour1.html

Marketing aside, Open Corsa KS's are great riding rubber. My personal favorite since I gave up sniffing glue. You have a different favorite? That's cool.