GP4000 Direction of Rotation

crumliniano

Imagine my surprise when gloating over my new wheels recently I was informed that the GP4000 tyres were fitted backwards! To my surprise it was pointed out that there are faint arrows and text on the tyre walls indicating direction of rotation. Apparently the thread layout pushes water away more efficiently if fitted in the correct direction. Worse still I lazily had them fitted in the bike shop. Should they have known better or is this not widely known. Egads!

DirkVoodoo

Always read the instructions before fitting.

I put my rear one on backwards, but my bike was upside down when I was fitting the wheel so I was getting the direction of rotation wrong in my head.

Gatorskins have the same tread pattern, so make sure you all check them too.

sy

Common mistake. Sometimes the arrow can be difficult to see. I too have been caught out by the upside down scenario posted by dirk:o

Stokolan

I was caught out with it myself when I first got them.

Ryder

Have been using gatorskins for years, never knew. Have to check tonight

Lumen

Given that road tyre treads are a marketing feature and make no difference to wet grip, I wouldn't worry about it. ISTR reading something about directionality of the tyre construction giving better grip in one direction; presumably you want more grip for acceleration at the back and more grip for braking at the front, but I still doubt it makes any difference. The tyres may be called "Grand Prix" but you're not doing F1 qualifying...

blorg

As Lumen suggests, I severely doubt it makes a blind bit of difference. Having said that I do put them on the indicated way, as well as lining up the graphics with the valve holes, etc.

Beasty

blorg wrote: »

as well as lining up the graphics with the valve holes, etc.

I've definitely failed my cycling proficiency test then:)

Ryder

Lumen wrote: »

but you're not doing F1 qualifying...

C'mon, there no need for that

crumliniano

I thought I'd stumbled on some esoteric fact! Hard to do that on this forum I guess . Well, glad to know I'm not the first to have these on backwards. I reckon you're probably right on the marketeers lumen, still though, hard not to fix them when you know you should.

DirkVoodoo

I am somewhat skeptical as to why tyre manufacturers would invest resources in modelling water dispersion if it were merely a myth to keep ignorant consumers happy.

I know, I know...hydroplaning is not possible on a bike, but it is still possible to lose traction and the GP4000's tread pattern is specifically designed to remove water from the contact point of the tyre (the middle) to the edges as quickly and efficiently as possible. They are still slicks and the rolling resistance and grip are not compromised because the contact area has no tread. So, having them the right way around you *may* see some benefit in high speed cornering in a race, although I'm sure rider competency becomes a larger factor in such circumstances.

Lumen

DirkVoodoo wrote: »

I am somewhat skeptical as to why tyre manufacturers would invest resources in modelling water dispersion if it were merely a myth to keep ignorant consumers happy.

I've read that car tyre manufacturers choose patterns which look attractive in the showroom. There are cases where they've ditched very effective designs because people didn't like the look of them.

tomasrojo

Armadillos also have a direction. I always follow it when installilng tyres, but strongly suspect it makes no difference at all to me, given my modest requirements from a bike.

biker_joe

HMMM years and years on research at Conti dismissed !!! :eek:

those two fat birds in the Conti Ads will be out for yer Blood lads ......

Biker Joe

Lumen

biker_joe wrote: »

HMMM years and years on research at Conti dismissed !!!

LOL. I'm not saying that they don't do good research, but tyre design is heavily influenced by marketing.

If it adds no more manufacturing cost to add a light tread pattern, sells more tyres and doesn't noticably degrade the grip then why wouldn't they use a tread?

tomasrojo

Lumen wrote: »

LOL. I'm not saying that they don't do good research, but tyre design is heavily influenced by marketing.

If it adds no more manufacturing cost to add a light tread pattern, sells more tyres and doesn't noticably degrade the grip then why wouldn't they use a tread?

Given how many people think that bikes can aquaplane, I imagine adding a tread probably does help sales alright.

blorg

biker_joe wrote: »

HMMM years and years on research at Conti dismissed !!! :eek:

Interesting to read Schwalbe's take on tread. Summary: on a smooth road, even in the wet, a slick will have more grip, and direction, even when specified, is of minimal importance on the road. That's coming from a pretty respected manufacturer.

Diarmuid

DirkVoodoo wrote: »

I am somewhat skeptical as to why tyre manufacturers would invest resources in modelling water dispersion if it were merely a myth to keep ignorant consumers happy.

unless you have access to highly confidential information, I'd doubt you really know how much then invest in modelling water dispersion. They might talk about it a lot, but it's probably just to sell a few more tires...

DirkVoodoo

Confidential? No, but it seems plenty of research institutes are funded by continental and their published papers are not "top secret", as long as you have a subscription.

http://www.ingentaconnect.com/content/tandf/vesd/2005/00000043/A00100s1/art00036

http://www.ingentaconnect.com/content/maney/prc/2002/00000031/00000010/art00007

I'm sure if you go through the various polymer and FEA journals you will find more. Of course I don't know exactly how much they put into tyre tread research, but to say that they make stuff up to sell tyres is even more ridiculous.

Lumen

DirkVoodoo wrote: »

to say that they make stuff up to sell tyres is even more ridiculous.

Can I interest you in some magic beans?

DirkVoodoo

Lumen wrote: »

Can I interest you in some magic beans?

Come on, they are German! German's don't tell lies!

DirkVoodoo

Well, I can't find any specifics, just that Continental AG spent 2 billion dollars in 2008 on "research" with no breakdown for their tyre division. 2 billion, big number.

There is also this cool pdf on vibration analysis done at their Hannover R&D facility, complete with cool laboratory pictures.

Diarmuid

DirkVoodoo wrote: »

I'm sure if you go through the various polymer and FEA journals you will find more. Of course I don't know exactly how much they put into tyre tread research, but to say that they make stuff up to sell tyres is even more ridiculous.

I'm not claiming that they are making it up, it makes sense that they have investigated the impact of tread on tire grip however all evidence points to two conclusions:

1. Tyre tread does impact the grip of the tyre (in a positive sense)
2. People's intuition leads them to believe that tread has an impact on the grip

I don't think it's a big leap of faith to say that any advertising related to tread on a road tire is as leverage on point 2 not point 1. Blorg's link from schwalbe seems to confirm this. (not to mention the bible)

Of course this is all IMHO,

Lumen

DirkVoodoo wrote: »

Well, I can't find any specifics, just that Continental AG spent 2 billion dollars in 2008 on "research" with no breakdown for their tyre division. 2 billion, big number.

There is also this cool pdf on vibration analysis done at their Hannover R&D facility, complete with cool laboratory pictures.

(googles)

OK

Industry wide, tread design is still done in 2D as a result of inadequate 3D modeling programs to meet the specific design requirements of the tire industry. CAD tools were too limited to handle the unique geometry of tread design, and available visualization software could not link to analysis or design packages without translations.

Since the tread pattern defines many tire properties, Kumho's KTC had three goals defined when they evaluated CATIA. The first was visualization from a flat 2-D tire pattern design to a curved, realistic representation for sales, marketing, and dealer input. These groups would determine customer reaction. If positive, the tread was hand carved to create a section of tire. The second requirement was the use of exact geometry for engineering analysis. Although a tread pattern had to be liked by the customer, ultimately how a tire pattern behaves determines the continuation of the initial design.

So, in this case it would appear that an engineering process is being used to produce tread pattern mockups for subjective cosmetic evaluation by unqualified idiots before any engineering analysis is done.

DirkVoodoo

Lumen wrote: »

ultimately how a tire pattern behaves determines the continuation of the initial design.

Lumen, the above clearly states that while aesthetics are important to continental in the marketability of a tyre, there is still significant development time remaining. I think what he is saying is that the marketing heads can't evaluate a tyre in 2D where all the design is done and 3D mock ups are made just for them and not as part of the engineering process.

Diarmuid, my point was with regard the Conti GP4000 and it's tread pattern being on the side of the tyre. The contact patch, which influences grip, is smooth. The sides of the tyre have the "grooved delta" pattern, which as they say act as channels for removing water from the contact area. Schwalbe are referring to tread patterns for added grip on the contact area, with a slick surface being superior. I never disagreed with this, hence why I did not counter Blorg's point.

blorg

@Dirk- most of Continental's business comes from making tyres (and other stuff) for cars and trucks where tread is important. I imagine most of the 2 billion is going on motorised vehicles. The studies you linked to were for cars, not bikes. Conti is not spending 2 billion researching bike tyres, the idea that ANYONE would be spending that money on bike tyre R&D is simply absurd.

Schwalbe's position is that bike tyre tread does nothing whatsoever for water dispersion but hold that while slicks are best for smooth roads a slight tread can be beneficial on rough roads- and a more pronounced tread utterly essential off-road.

Conti is pretty unique BTW in making a case for a water dispersing tread on road racing tyres, no other manufacturer seems to think it necessary or beneficial. Even the wet weather specific tyres from other manufacturers, like the Michelin Pro3 "Grip" are slicks.

DirkVoodoo

blorg wrote: »

@Dirk- most of Continental's business comes from making tyres (and other stuff) for cars and trucks where tread is important. I imagine most of the 2 billion is going on motorised vehicles. The studies you linked to were for cars, not bikes. Conti is not spending 2 billion researching bike tyres, the idea that ANYONE would be spending that money on bike tyre R&D is simply absurd.

The "2 billion being a big number" was a slight hint at that, I'm not an idiot, I know that continental are involved in tyre manufacture for vehicles as well as electronics and drivetrains.

They are also one of FIFA's main sponsors, as such, I am replacing all my tyres with another brand.