Tyre change time

[Hitcher]

I'm about due to change my OEM Bridgestone Battlax 020s and was wondering if anybody had any recommended dos or don'ts for rubber for the ST. The rear OEM will have done about 12,000km come replacement time.

My last ride (up until a month ago) was a Kawasaki ZRX1200R which really loved running Metzeler Roadtec Z6s. I was contemplating putting the same rubber on the road under the ST.

[hippo888]

I like the Metzler Z6's a lot more than the BT 020's. They have more linear turn-in. I think the BT 020's are more triangular in profile while the Z6's are more round. The Z6's are also more resistant to following rain grooves and aren't as slippery on tar-snakes as teh BT 020's.

I live in MI, so I don't know what curves are. You'll have to ask someone who can really use their tires about issues such as grip. :p

[Killtimer]

I like the Metzler Z6's a lot more than the BT 020's. They have more linear turn-in. I think the BT 020's are more triangular in profile while the Z6's are more round :p

Sounds to me like you may have gotten the 020 "U" or general replacement tires. If so they are exactly as you say, more triangular. The OEM 020's are designated "F" and are much more rounded, as well as having a totally different construction. Are you comparing the 020's that came new on the bike or were they tires that had replaced the originals?

Steve

[Northern Rob]

I switched my Metzeler (bias ply) for Michelin Pilot (radial) sport touring tires and I felt a noticable improvement. I would recommend checking out the Pilot tires. I ride pretty aggressively but not "full out". Hope that helps.

[Don Webster]

Just replaced my avon 45/46 with Metzler Z6's so far so good. Avon's got pretty good mileage for a Sport/ Touring 10000 miles. But front had the low speed wobble. Z6 have no wobble even when taking hands off bars on the coast down. Ran it up to 130 mph windshield all the way up rear tour box on no high speed weave other than what I would expect from the wind. Will see how they do on mileage if they don't get about the same as Avons I may go back to them. The Avons were solid at top speed 140/145 & once you know what it is the low speed wobble is not that big a deal.

[Dave Wicks]

I'm a long ways from needing tires at the moment but will likely need change by late in the season. I'm seeing some positive comments about the Micheln Pilot Road tires. Anybody try these, supposed to be good in rain, rounded profile, stick good and wear well. Guys are using them on the 1100 Blackbirds, quite impressed. Any ST,ers use them??

[Hitcher]

Well, this turned out to be a bit of a non-event! Local suppliers couldn't do me anything other than 020 Bridgies! The ST's oddball front size makes a big difference when shopping for a "set".

So Bridgies it is for the next 12,000km!

I'll make a point of ordering earlier next time...

[Dave Wicks]

Checked out CalSci, they have the correct size for the rear $111.00, and a 110/80/18 for front, not the 120/70/18...good looking tire, lots of rubber on the road...Wonder what taller thinner tire would do at front..Might work, why don't you try it and let me know....????? Anybody use that type of tyre??

[seiseman]

When I looked on the Michelin site http://two-wheels.michelin.com/2w/front/affich.jsp?codeRubrique=2092004113028&lang=EN they don't list Pilot Road's for the ST1300. BUT if you switch countries and pretend that you are from the UK (of course, if you ARE from the UK you don't have to pretend...:D ) you can get the correct sizes for the ST1300 Pan. What gives?

[Bill Ishmael]

When I picked my ST1300 up from the dealer, after having the harness recall taken care of, the wrench made me aware of the decreasing tread in the rear tire. I have been watching it for a while now. It is almost down to the wear bars. According to others on this site, I still have a couple of thousand left until the cord starts to show. I have 6300 on it now and am not very agressive (geting to old to get a thrill out of scaring the crap out of myself anymore). These are the tires that came with the bike. Does not seem like 6300 miles should be the change out milage for modern tires. Am I correct?
Bill

[Putt]

Bill,
I have the OEM's and have 9000 on them at the present time,
they look like they are good for a couple thousand more...


Putt...

[Putt]

Charlie,
Tire contact area is a function of air pressure and weight supported..
500 lbs / 40PSI = 12.5 sq inches of contact area.. Does not matter
how tall/wide the tire is, it is still going to have to have 12.5 sq.in
of contact area.. On a narrower tire, the contact area will be narrower,
but longer.. conversly, on a wider tire, it will be wider but shorter...
Sidewall flexibility is probably more of a factor than contact area
(tucking)...

Putt..

[SporTnTR]

Only got 4300 mi out of the pair of OEM 020's. I do ride very hard tho. And there are a lot of floattop roads around here and they too are hard on rubber.
I had some wear left in centre, not much tho, but the sides were bald. They were at 4000 mi but i squeeked another weekend out of them while putting around a lot slower. I put Z6's on but 200 mi later serious winter set in.

[CruisingDog]

I've just changed my tires from the OEM Dunlops. I got 9700 miles out of them. I've been doing some wet riding here in California (ok, it's not too often that happens!) and the Z6's are definitely more "sticky". I also feel that they are more uniform when taking the more aggressive turns (more eliptical shape in the cross-section of the tire). Rain groove issues are gone now and wobble is nearly non existant.

The things I really like:

The Z6's instill a bit more confidence in the corners (they just feel more stable for some reason)

The rain groove issue is gone

I've only got 500 miles on these so far so I'll have to see how the wearing goes. Hopefully the don't grind down too quickly!!

[NormanPCN]

Charlie,
Tire contact area is a function of air pressure and weight supported..
500 lbs / 40PSI = 12.5 sq inches of contact area..Putt..

Where do people get this from? The air pressure is not holding up the vehicle. Think about it. The tire is symetric. The air pressure in the tire "pushes" in all directions equally. All forces cancel out.

Also I can build you a tire, a rubber one, that is hollow with zero psi inside (yes a vaccum) and you could ride on it. Granted it would be a very rough ride and not at all safe. Such a tire invalidates the given equation since you end up dividing by zero.

Such an equation ignore the strength of the carcass itself. Put a Jeep on a set of radials and the same size tire in a set of super swampers (7 heavy bias plies) and you see this effect. You can remove the valve stems and off road on the swampers. The radials would not hold the jeep up.

Air pressure makes the tire carcass more rigid and thus stronger. Another way to think about it is that the more air you put into a tire the more "solid" it becomes.

[basco]

Where do people get this from? The air pressure is not holding up the vehicle. Think about it. The tire is symetric. The air pressure in the tire "pushes" in all directions equally. All forces cancel out.

Also I can build you a tire, a rubber one, that is hollow with zero psi inside (yes a vaccum) and you could ride on it. Granted it would be a very rough ride and not at all safe. Such a tire invalidates the given equation since you end up dividing by zero.

Such an equation ignore the strength of the carcass itself. Put a Jeep on a set of radials and the same size tire in a set of super swampers (7 heavy bias plies) and you see this effect. You can remove the valve stems and off road on the swampers. The radials would not hold the jeep up.

Air pressure makes the tire carcass more rigid and thus stronger. Another way to think about it is that the more air you put into a tire the more "solid" it becomes.


Just saw this one.

Maybe people get idea from basic phyics? People don't ride on static tires. In the statement above proves that you are not in the tire business. Let air out, bike/car go down, cords and wall are not holding the tire up. Pressure is not exerted in all directions, only radiating out and exerted on the wall of the tire or a vacuum would occur. Misinterpretation of the equation is another problem.

If you don't understand, read this tire phyics (http://www.madsci.org/posts/archives/feb2000/951617801.Ph.r.html)

[Motorace]

Air pressure has everything to do with with keeping that tire working. Less pressure = more heat, more wear, more flex in the casing.

Air pressure does not make a casing stiffer - it is what it is as soon as it pops out of the mold. What the air pressure does is support the casing and allows it to work.

Less pressure may put down a larger contact patch - to a point. Then, you begin to deform the casing and the tires shape on the ground may begin to resemble a W. The deforming of the casing in this way will cause improper wear.

And the size of the air chamber also dictates cooling. This is one of the advantages a tire like a 19/67-420 gives you at a track like Road America or Monza. Having a casing that is running too low a pressure will cause flex in the belts and this will also generate heat.

If it gets severe enough, you will either overheat the rubber (it turns into dry crumbs) or it will delaminate in patches from the casing - I have race tires that show both these instances.

Air pressure has to be the biggest culprit with tire problems and is always the first question we ask.

A taller tire will steer slower. What tire companies do to speed up response is to go to a shorter sidewall - 110/90-18 to a 110/80-18. Or in the case of sportbikes like the YZF-R6, a 120/60-17 to a 120/70-17 to slow down response.

Aspect ratio is also set to determine how the tire will cool. A larger air chamber - with everything else equal - means a cooler tire.

A narrower tire will also speed up steering due to a smaller contact patch, and the trade-off is stability.