Vixar

...between one which has plain surface and one with treads, assuming they have the same width, on: 1. dry asphalt and 2. wet asphalt ? Or maybe it's no difference ? (just to pick up an exemple, let's say Schwalbe Kojak vs. Marathon)
What do you say ?

Trakhak

Quoted from this page:

As far as grooves and tread are concerned, a slick tire offers the most traction on a paved road. Grooves are a void in rubber contact with the ground, so a slick tire is best. A groove could help move water out from under the tire, but the surface area of a road tire is so small that a groove offers very minimal benefits even in wet conditions [but see quoted text below; Jobst Brandt would say "no benefits"]. In most cases, the grooves are applied as a marketing and psychological sales tactic since the average person relates them to “more traction.” In reality, think of Formula One racing—they will stay on slicks tires till the water is pooling on the track. Remember, this is a bit different when the riding surface is loose, and it’s the reason gravel tires have lugs/knobs.

And from this page:

Tread patterns have no effect on surfaces in which they leave no impression. That is to say, if the road is harder than the bicycle tire, a tread pattern does not improve traction. That smooth tires have better dry traction is probably accepted by most bicyclists, but wet pavement still appears to raise doubts even though motorcycles have shown that tread patterns do not improve wet traction.

Vixar

Thank you !!!

Sy Reene

It seems counterintuitive. You would think that a tread's micro ridges creates more friction in a braking situation than would a smooth surface.
Not tires, but how about rubber jar openers? No difference resulting from texture?


textured

smooth

Troul 

Slick tire with a high coefficient is what I'd be looking for if traction was the ultimate goal for a bicycle road tire.
caveat; higher traction isn't guaranteed when temperatures are not optimum.
Example: an automobile tire grade AA is highest grade* for traction; in temperatures it was designed for its purpose of use. If the temperatures fall outside the optimum window, debris [sand] & such will alter the capability.

jgwilliams

In wet or dry I'd say the hardness of the rubber compound has a greater effect than the presence or absence of grooves. But then, a softer compound will wear out quicker so, as with so many things, there are really too many variables to make the final choice simple. I've found Conti GP 4 Seasons to be good all-rounders, but if you accidentally lock a wheel in braking it can take the surface layer off. Michelin Pro 4 Endurance are almost as good and don't seem to suffer that handicap, so that is what I now use. The Conti tyres have a hint of a tread, the Michelin's don't, but they're both quite soft, grippy compounds and I've never felt unhappy with either of them in the wet or the dry.

Trakhak

Counter-intuitive is right. I still struggle to understand how micro-ridges would diminish friction. In addition to the example of jar openers, why did we evolve to have fingerprints? In anticipation of Bernoulli coming along to ID criminals in the 1880s?

terrymorse 

The Schwalbe Marathon Almotion Addix gets a wet grip score* of 77.
The Schwalbe Kojak gets a wet grip score of 74.

The tread probably has little influence on the scores.

Compare with the Continental Grand Prix 5000 All Season, a slick tire, which has a wet grip score of 77.

* - wet grip scores from bicyclerollingresistance.com

PeteHski

[QUOTE=Sy Reene;22850686]It seems counterintuitive. You would think that a tread's micro ridges creates more friction in a braking situation than would a smooth surface.
Not tires, but how about rubber jar openers? No difference resulting from texture?



Micro-ridges probably would create a little more grip, but they would very quickly wear smooth so there isn't much point in applying them to tyres. Deeper tread patterns are not the same thing as you then lose significant surface area and tread stability. A tyre with a significant tread pattern needs to be made of a harder compound to provide adequate block stability. The only point in treaded tyres for use on smooth pavement is to prevent aquaplaning in the wet and bicycle tyres are too narrow and speeds too slow for aquaplaning to ever be an issue.

So smooth bike tyres will be better on pavement. Tread patterns on road bike tyres are either cosmetic or to provide more grip off-road on loose surfaces. So it makes sense for gravel tyres to have a tread pattern.

Sy Reene

[QUOTE=PeteHski;22851137]I guess there's just a lot of big-tire marketing out there, but I'm a sucker for it I guess -- always like the corsas, and maybe the marketing copy is a bit exaggerated:
"This chevron tread pattern adds dynamic performance to the Corsa Control tread, allowing for increased grip on slippery surfaces, as well as added durability."

PeteHski

[QUOTE=Sy Reene;22851293]Increased grip AND added durability is pushing it a bit. They do look pretty though.

terrymorse 

A few years ago, there was some talk in the tire world about "micro tread" increasing traction. I forget which tire company guy was going on about this (maybe he was from Continental).

The argument went that a slightly irregular tire surface lets the rubber "hook up" with the small surface irregularities. He was talking about a tire roughness of less than 0.1 mm, which will happen after riding a brand new tire for just a short while. That's also why a brand new tire can be slippery, as the surface is too smooth to "hook up".

wolfchild

Rubber compound, tread compound and tire pressure has more effect on traction than the tread design.

jp911

In the world of cars and motorsport, the advice given when someone asks how to improve braking/stopping power is to (first) get grippier tires. After that you can start throwing money at performance brake pads, vented rotors, big brake kits, etc.

79pmooney

I find It's easiest to smooth side against my SS coffee pot to screw it tight. (Italian Moka pot.)

+1 I loved the Vittoria Open Paves with the green tread stripes for their wet weather traction. Great tires for atrocious weather until you needed tire size. (I don't think I ever saw bigger than 27c but that was before the big tire craze.) The new Corsa G+ (and I assume the newer G2.0) are close to the Open Paves (and much more durable). I'm about to do my first ride on the G+ Control (28c tubulars) and it wet so I'll see what that's like (though I have no intention of pushing any boundaries.

sjanzeir

I find that the ones made of rubber are exceptionally good at braking.

79pmooney

[QUOTE=PeteHski;22851330]The graphene tires are simply better. Game changers. That old star diagram with the points being rolling resistance, grip, durability, etc where the developer of the tire had to chose which features to amplify and which to let slide ... well the new graphene allows the total assets to add up to a higher number. Developer still has to choose, but the choices are better. You can improve everything a little or some features a lot. I've been riding the Vittoria G+ tires a lot. Not quite the wet road grip of the older pre-graphene Open Paves but close. And radically better for cuts, tire wear and rolling resistance. Just came home from my first wet G+ Control ride. With too much pressure (I pumped them hard yesterday for max size to fit fenders) they felt very secure on slightly uneven pavement. And I bet if I dropped the pressure from close to 90 (28c, 150 lb rider) I bet they'd stick like glue. The tread of your photo, just (I think) G+, not G2.0. (Vitt's tubulars wear less labeling than their clinchers.)

PeteHski

[QUOTE=79pmooney;22852375]But they were talking about the Chevron pattern, which along with the grooves, is mostly cosmetic. The compound is a completely different story.

georges1

For me, it has to the conti grand prix 4 seasons followed by the michelin pro 4 endurance. I had michelin axials before that and michelin performer and never had probs in case of hard or sudden braking[img]chrome-extension://bpggmmljdiliancllaapiggllnkbjocb/logo/48.png[/img]

Lombard

Best answer so far. Your comment about marketing reminds me of the sales gimmick of directional bike tires to prevent hydroplaning when in fact bikes don't hydroplane because their contact patch isn't large enough nor are they ever going fast enough to hydroplane.

rsbob 

As a blanket statement, directional bicycle tires are a marketing scam? Are you aware of any studies or is this a hunch?

Lombard

I think it would be more fair to ask are you aware of any studies that show that directional bicycle tires have any real advantage? Are you aware of any studies that show that bikes can actually hydroplane?

Sy Reene

I'm more wondering if anyone can actually point to any bike tire marketing webpage where the claims are being made about hydroplaning prevention.

rsbob 

Thank you. I will defer all future posts to you for grammatical correction. Maybe you could rewrite that for better clarification. Too funny.

sjanzeir

Beat editors, managing editors, and an editor-in-chief is just what this forum needs.