Author Topic: Sport Tour Tires - Traction is Everything!!  (Read 4443 times)

Offline elvin315

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Sport Tour Tires - Traction is Everything!!
« on: May 17, 2011, 07:34:16 pm »
Rossi-Stoner Laguna Seca 2008 battle (The video's owner prevents external embedding)
MotoGP - Laguna Seca 2008 Finale,  Valentino Rossi vs. Casey Stoner

AVON STORM/AZARO

The Azaros were the premiere sport tour tires for the Concours when they first debuted. Avon's replacement for the Azaro was the Storm. They decided though, that there weren't enough bikes using 150/80-16 tires to justify making the Storm in that size so the just continued to make the Azaro rear for those bikes. The Storm front was designed with that in mind so it's perfectly safe to use them together.

I became a believer during the 2003 COG National Rally. Six days of riding through torrential downpours on interstate highways at insane speeds, and later clinging to the gnarliest knotted ribbons of wet asphalt ever poured over the narrow goat paths of West Virginia, Tennessee, and North Carolina, proved their superior wet weather performance to me. The last three days were relatively rainless. In the dry they stick like Velcro.

The Azaros saved my butt when I was riding with friends on supersport bikes and I pushed my personal envelope to keep up. I was dragging pegs regularly and that's something the Dunlop 205s I used before never gave me the confidence to do. Not that they couldn't handle it just they didn't give me good feedback. I felt I was wrestling the bike through the turns. The downside is that they wear quicker than the harder compound touring tires. Expect about 12,000 to 14,000 miles for the front tire and 8,000 to 10,000 miles for the rear. Depends on how conservatively or aggressively you ride.

The Avon's cross-section makes a heavy bike like ours almost flickable. Now a push on the bars and the bike drops into the turn and stays there until I push the other bar to stand her up. I was smokin' through those quick left/right/left/right transitions. No tires will turn you into Valentino Rossi. It's the rider more than the bike, or tires, but the Avons helped my confidence more than any tires ever have.

CUPPING

Tire cupping is a wear pattern where the tire develops unevenly worn tread blocks. They can be seen but are much easier felt with the hand. It is chiefly caused by the tread blocks being flexed and deformed under the force of braking and the lateral G-Force encountered during cornering. The Connie's weight doesn't help, adding to the load the front tire must cope with. The rear tire cups also but less than the front. That's because the braking force, thereby the flexing, is less and that wear is balanced out by the wear from acceleration. Plus they don't have to contend with countersteering inputs like the front. When you countersteer you are making the front tire "crab" through the turn. It's rolling at an angle compared to the line traveled so the blocks are scrubbed against the road surface.

Underinflation doesn't help. "Proper over-inflation" can lessen the cupping but doesn't eliminate it entirely. Many of us inflate to 40-42 psi front and 42-44 psi rear to stiffen the tires. It seems to help. Well, at least it doesn't hurt. (Funny, but those pressures seen to work with most Concours tires regardless of brand) Too much air can hurt though. If you severely overinflate the contact patch shrinks and the tire tread and sidewalls won't flex enough to fully grip the pavement. Of course tires of different tread patterns, cord/belt construction, and compounds will cup to different degrees. Weak or worn suspensions contribute to tire cupping too. They won't allow the tire to follow the contour of the road and so it skips along the surface. Stiffer springs and 15 weight fork oil improve handling and ride as well as reducing tire cupping.

The smaller the tread blocks, the easier they flex. The long diagonal blocks on the Avon Azaros and other tires with asymmetric tread patterns resist cupping because they are angled to the lateral and inline forces. Even the center groove on the ST45 is angled. The ST55 does away with it altogether. See for yourself. Compare the Dunlop D205 & D220 with the Avon ST45 Azaro & ST55 Storm. The Dunlop sipes (groves) are angled too, but the blocks are smaller and closer together:
http://arizonamoto.com/Merchant2/graphics/00000001/D205.jpg
http://arizonamoto.com/Merchant2/graphics/00000001/D220.jpg
http://www.avon-tyres.co.uk/motorcycle/images/tyres/big/azaro-st_av45.jpg
http://www.avon-tyres.co.uk/motorcycle/images/tyres/big/av55.jpg

The "perfect tire" is the Holy Grail of Sport Touring, but the Avon Azaro (and now the Storm) comes close to it for me. The following is a page dealing with tire wear.
http://www.rattlebars.com/valkfaq/tirewear/ (Tire Wear Article)

TRACTION vs. MILEAGE

The AV45 Azaro was superseded by the AV55 Storm. Avon keeps making the AV46 Azaro for all us riding antique bikes with 16 inch rears. The AV55 front and AV46 rear are considered a matched set. I use them and hope Avon makes them for as long as I own my Connie which might be until I die. They stick like crazy glue, wet or dry. I will ride long distances droning along the highway to get to the twisty roads I prefer but will not trade traction for long tire life.

I frankly don't see the sense. Our bikes don't have ABS. We only have our reflexes and braking skill to keep us from ramming something hard. If the rubber wrapping our wheels is hard we can skid into the very thing we're trying to avoid. If the rubber is soft it will grip the road and maybe save our asses. Simple.

When I hear, "I don't ride fast or aggressive enough to need sticky tires" I cringe. You'll need them to swerve quickly to avoid hitting the broom that fell of the pick-up truck ahead of you. You'll need them to stop before you cleave that deer in two. You'll need them to skirt that rock laying in the arc you're taking through that blind curve. I did when those things happened to me. I've only used the OEM Dunlops, the D205s, and the Avon Storm/Azaro combo on my Connie. Been riding for 30 years and I've learned a lot, mostly the hard way. An important one is that soft sticky tires help you go quicker, stop shorter, and turn faster. Repeat after me,

"Traction is Everything".

Some owners will say they get great traction from the GoldWing sized touring tires they use on their Concours. They just might. I have no experience with those tires so I can't say for certain which one is better. What I'm saying is that I prefer a sticky tire like the Avon Storm/Azaro. People can agree or disagree as they see fit. You use what works for you. I'm not the world's greatest rider. I have no illusions. I do the best I can and prepare for the worst. I wear ATGATT and fit my bike with the best suspension, brakes, and tires I can afford. I worry less about zero to 100 and more about 100 to zero. And I do love those twisty squiggly lines on the map. For me a soft tire is better than a hard tire.

I even use different sets of tires on my car. All 4 wheels. I see all-season tires as a compromise. They can't possibly provide the grip I want across such a wide range of weather conditions. I use tires specifically designed for the weather they're likely to encounter. But that's just me.

WARNING:
Regardless of the tire you choose here's a little safety tip. Take a foam sanding block and remove the shiny surface coating of Mold Release. That's a liquid sprayed on the inside of the tire mold before the rubber is injected. It aids in pulling the tire from the mold. It's very slippery, both in the dry or wet, and had tossed many a rider and bike to the tarmac. You don't want this to happen to you.

new Gixxer crashed