ASK THE EXPERT “DUNLOP TIRE”

On Friday evening, we attended the monthly meeting of IL. A-2. They had been experiencing a problem with a few of their rear tires. So they invited a representative from Dunlop Tire to come to this meeting and have a discussion with GWRRA members. A-2 extended an invitation to staff members of other chapters to come, and we decided to attend, representing G-2. Primo Marotto, regional sales manager, gave a little seminar with a video tape of how their tires for motorcycles are actually made, and passed around a sample of an Elite tire as well as a sample of a radial tire. He talked about the process and the difference. Questions were asked and answered. Here is a overview of the discussion:

First to the problem with the tires that they ex-rayed and tested, they felt that the problems stemmed from some object that protruded thru the tread and possibly thru one level of cord underneath, and was dragged along the tire for a small distance. Over time, it spread open and split. They felt that nothing was wrong with the tires to begin with and when they compare lots and times and purchase locations, nothing indicated a trend, that would point to a manufacturing problem. Most at the meeting seem to agree with the perspective.

The following are an at random list of items mentioned: The only difference between the original tires K177 and the Elite 491 is the tread pattern. The Elite pattern is suppose to be better in the rain and handle better. All other factors of the tire are exactly the same. Compound, construction, dimensions, etc. So, I asked, why isn’t Honda putting them on the new bikes? He said that once a manufacturer decides on a tire, its near impossible to get them to change. They said that they have tried to get them to change but……. I asked then, why the difference in the recommended tire pressure from the originals to the Elite’s? He said that it was Honda that suggested the pressures not them. They would have the same pressure used in both sets of tires. He also leaned heavy toward more air than less air. And this would match most points of view, as under inflated tires are the most dangerous. On Elites, up front, it was suggested to use 36, but even as much as 38 lbs. for the heavier loads. In the rear, 41 lbs., you could go 42 if you need to. It was mentioned that even in the cold mornings check the pressure and adjust, even if later in the day it will be in the 70”s. There is a built in 20% fudge factor to allow for increases in pressure due to riding and hot summer days. They recommend not using any cleaners on the tires cause after they dry, they pull out the chemicals in the tires and they age faster. The only cleaner suggested was Murphy’s Soap, again no other. To read the date the tire was made, find the letter and numbers that start with DOT, which is located near the rim of the tire. To the right will be an oval shaped depression with three numbers in it. The first 2 numbers are the week of the year and the last number is the year. Example: 128, 12^th week of the year, 1998. A change is taking place for 2000, there will now be four numbers, the first two for the week and the second two “00” for the year. There is also a yellow dot on the side wall which is the lightest part of the tire, and this is where the valve stem should go, when they mount the tires. If they don’t mount the tire exactly where the yellow dot is, its not necessary to change that unless you have more high speed vibration than usual. The weights for balancing should take care of most of it. Shelf life for their tires, up to 3 year won’t be a problem, but after that they tend to get harder and won’t flex as they should. They suggest not ever riding on a plugged tire, replace it. In a newer tire a plug/patch could be used, but….you decide.

Dunlop says that with the width of the rear wheel, that a radial can not be constructed to handle the load of the touring bike. Radial tires are successful on performance machines, excelling in handling and grip, but not tire wear. In order to make a radial that would handle the load Honda would have to have a wider wheel. Until then, Dunlop says that will stay out of the radial game. Radial tires use much less material and are a lot lighter than our bias belted tires. Stayed tune to see if competition will force their hand.

We want to thank A-2 for inviting us and being good host. The seminar was very informative.

David and Kathy Bierman

“the Educator”

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