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Discussion Starter #1
Hi guys

Just fitted today on front and back the so talked about Pirelli´s Angel ST. Just rode a few dozen miles (still burning the initial rubber, so not going to loose my head on twisties before a couple hundred miles) so I really can´t feedback a lot, but first impression is so much more confortable.!

One thing puzzles me though.. the front type seems somehow to be mounted opposite way.! the arrows are correctly pointed, and with the angel facing forward it seems that the front tyre instead of pushing water away it pushes to the inside of the tyre itself.. in my head it makes no sense!

The back tyre is ok, seems pointed the right direction tu push water away!

photo sample:

http://www.motorcycle-usa.com/PhotoGallerys/xlarge/Pirelli-Angel-ST-Tire-15.jpg

can anyone clear me out on this..?

thks
 

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this has been the question hasn't it. I think a real tire expert is going to have to be consulted on this one. Until then, I think you should stay with the manufacture's direction arrow for now. Just my 2 cents.

Donn
 

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Unless you have two wheel drive it is pointed correctly. Picture yourself being towed by a car and you lock up the front wheel, which way is the dirt or water going to travel?
 

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Funny you should ask. Had mine installed at a local shop by the owner who is a former racer and has installed thousands of tires over many years. I had the same reaction and told him the front was on backwards. He gave me some cosmic answer about cutting though the rain to allow the rear to work better. What? Figured I better shut up and go with the flow(so to speak). Sorry, not much of an answer but the tires are awesome.
 

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I sent this question to Dunlop tires usa. I will let you know as soon as the reply back, if they do.

Donn
 

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Discussion Starter #7
Ok, so what I found out googleing the net is

1 - The inverted front tyre grooves was pioneered by avon in the late 80´s;
2 - traction in motorcycles is in the back and not in the front;
3 - car tyres science has not a lot in common with motorcycle tyres;
4 - The objective of front to back inverted grooves (ie pointing at each other and not pointing both at the front) is to allow the back to work better for traction, and the front to work better for braking;

The assumptions in this case does make sense.!

But for water dispersion on the front it doesn´t... if I think of it theoretically the front tyre grooves will be pushing water to the center area of the tyre, thus favouring aquaplaning ! then again if water dispersion on the front is irrelevant compared to braking, what´s the sense of water dispersion grooves at all?

and then some more added confusion:

5 - Most of i.e. BMW cars have traction on the back and that does not necessarily means their front tyres will use inverted grooves opposing the back!

who am I of course to question some tyre manufacturers choices but.. mm... in my mind still have to be convinced with a few more understandably clear arguments.!

rgds
 

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If you picture the grooves on the tread footprint you will see they point out and back. That's what disperses water.

Not a lot of wear in required for modern tires. Once they're warmed up they are ready to experiment with cornering grip. You should find them nice and sticky leaned over, they have a pretty aggressive profile.

Personally I think they're a great looking tire, and they seem to get good rider reports. Stock tire on some of the ducati models, hypermotard and/or monster IIRC.
 

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Hypothetical situation: Your tooling down the freeway in the rain, start hydroplaning and manage to stay upright, you would definitely want the rear wheel to recover traction first, and given the fact that it is a wider tire would be more prone to hydro than the skinny front. the only thing tire manufactures have to compensate for this is the tread design. IMHO
 

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so not going to loose my head on twisties before a couple hundred miles
Why? New tires are scuffed as soon as you scuff them. My tire fitter says, "Ten miles and ten turns", but I'm not even sure ten miles is required. Be gentle until you get the shiny stuff scuffed off, then have it. Works for me anyway, and has for many years and many tires.
 

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Your front tire is mounted correctly. I've been riding for 40 years, and every front motorcycle tire I've seen, that has a v-type tread, has the v pointed forward when it comes in contact with the road. Its for better braking, and your front typically handles 80% of your stopping force.

Also, think of the tread this way, no mater what speed you are riding at, when a tire rolls down the road, at the point where the rubber is in contact with the road, it's speed is zero. Think about it. (the exception is when you lock up your brakes and start skidding)
 

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agree -- a couple of hundred is a *lot* more scrubbing than is necessary.

disagree -- if you are hydroplaning, i think you want the front to recover first. even Rossi can save the rear more easily than the front.

the groove look backwards for clearing water when upright, but when you are upright, the narrow profile doesn't really need the grooves to clear water. imagine how the treads land with the bike leaned over. seems to me that the leading edge of the 'backwards' groove would send land first, casting water aside to improve cornering grip. i believe race rain fronts are cut the same way, though i haven't paid close attention lately.
 

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Discussion Starter #14
interesting thoughts guys, we´re getting into physics theory lol

I don´t really care a lot about how the tyre looks CJ, I´m mostly function over form regarding tyres, they are the live hangers and all

Also thought of it this way- the front grooves will push the water out to the front, and away? if that´s the case then left/right water channel pushed by tyre will be a tad farther apart when it reaches the rear, how about that hehehe

well now after about 100 kms all I can say is wow.. the front trajectories now follow through start/end twistie without a glitch, the back just follows the front like nothing´s there (and that´s good!) and general behave is the bike does all I force her into, with a higher tonic on the nature born versys character.. best regards kawasaki for building this versys frame assembly.. a hidden diamond for most (not you guys, I know where I am lol)

Now starting to lean as I haven´t before with the d221´s.. feel like a teenager with a 125cc on the traffic lanes too.. sorry Speedy but soon you are going to get scrapped, keep a pair on backlog for my next order hehehehe
 

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>snip
I don´t really care a lot about how the tyre looks CJ, I´m mostly function over form regarding tyres, ...
>snip
When I say 'look good' I mean they look like they will work good. The have an aggressive tread pattern and profile, sticky rubber, designed for performance.

Glad to hear you like them.
 

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Why? New tires are scuffed as soon as you scuff them. My tire fitter says, "Ten miles and ten turns", but I'm not even sure ten miles is required. Be gentle until you get the shiny stuff scuffed off, then have it. Works for me anyway, and has for many years and many tires.
Some racers will have a new unscuffed tire on and be hammering it through the turns first lap. Dont think you need to be that careful.
 

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http://www.motorcycle-usa.com/PhotoGallerys/xlarge/Pirelli-Angel-ST-Tire-15.jpg

MHO- its pointed in the right way to disperse water, may look odd but there is a lot of work done on the thread patters for safety of the rider.

"lets say the tire has a v-pattern shape with the tip of the v in the centre or the tire. the tip hits the surface of the road first an the water would travel towards the outside of the tire as it rolled forward"
 

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Discussion Starter #18
http://www.motorcycle-usa.com/PhotoGallerys/xlarge/Pirelli-Angel-ST-Tire-15.jpg

MHO- its pointed in the right way to disperse water, may look odd but there is a lot of work done on the thread patters for safety of the rider.

"lets say the tire has a v-pattern shape with the tip of the v in the centre or the tire. the tip hits the surface of the road first an the water would travel towards the outside of the tire as it rolled forward"
well my original guess exactly.. on that photo the side arrows would touch the water first and then pull it to the center of the tyre, that´s what I got bugged about
 

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the lame response or answer from Dunlop Tires to ninogui question.

Good afternoon Donn,
Thank you for contacting Dunlop.
The tires were designed this way for optimal handling, performance and wear.
regards,

Consumer Affairs
Dunlop Motorcycle & ATV Tire Division

Goodyear/Dunlop Tires N.A., Ltd
PO Box 1109
Buffalo, NY 14240
Ph: (800) 845-8378 Fax: (716) 879-8425

"Contains Confidential and/or Proprietary Information. May not be Copied or Disseminated Without the Expressed Written Consent of the Goodyear/Dunlop Tires N.A."
 

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Inverted Front Grooves (IFG) as Avon calls it are for:
1.Resists irregular wear
2.Smooth handling throughout tire life
3.Improves wet braking/stopping distances

http://www.avonmoto.com/wp-content/uploads/AvonRangeStorm2Ultra.pdf

Had send this question to Bridgestone UK and awaiting their reply.
Had read something on this in Bridgestone's BT023 sales brochure but can find it.
 
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