Tire

just installed a new tire on my 99 fxdwg. the tire i took off had 8,000 miles on it. and all this time the arrow going in the wrong direction. but the bike handled great. so my question is why do they want you to install the tire in the same direction as the tire turns or in the diection it gos down the road. thanks

Tread Pattern I Would Think, For The Way It Grips The Road In Rain Or Turning Alot Of Car Tires Are Directional Also. I Would Take It Back And Have Them Put It On Correct. I Always Make It Clear To Them Which Is The Drive Side.

maybe something to do with the way the cord is wrappped

Handling and most important is to channel water outward. You won't notice to much difference on a dry road, however,the tread is designed to channel water from the center of the tire outward. If you mount the tire backwards, the water will flow to the center of the tire and can cause the tire to hydroplane.

When a tire is designed to be uni-directional it can, as a result, have tread designed to maximize tread life and the evenness of tread wear, maximize traction (not the 'stick' part but the 'grip' part) as well as build in a self-cleaning propensity and better anti-hydroplaning (water shedding) ability.

As to bias ply tires ... the direction of rotation indicated by the arrow means that as the tire rotates its contact patch will, with EACH revolution, cross from a higher (outside) belt to a lower (inside) belt. This puts no separation stress on the junctures. Had the tire crossed from lower to higher bias there would be separation stress imposed on the juncture with each and every rotation. The amount of stress is trivial in most cases and would not CAUSE the belts to separate. However if the belts begin to separate, this rotation stress would immediately cause a horrible event. Rotation-caused stress tries to increase the separation if rotating in the wrong direction and tries to close any separation if rotating in the proper direction.

Enough of the engineering gumbo jumbo. Bias tires have an arrow on them for a reason or they would not be there. Tire rotation direction should always match the arrow that is placed on the tire. If there is no arrow, then the tire you have is not uni-directional and can be mounted to rotate in either direction.

I would have the idiots give you another tire.

Thanks To All For This Info. Now I Know!

jeez linda,,,read your chat about tire on backward,,,i am getting ready to leave in may,,so checked mine the other day,,, yup on backward,,, probably did it myself,,, only have 9100 on it,,, normaly get way more than that ,,so i would assume ,,at least with tires i run,,,they wear faster on backwards,,, i am going to run it till week before i leave,,, pops

Tire on backwards

Putting a tire on rolling the wrong direction is a mistake even experienced mechanics make, so if you have a tire put on somewhere, make sure you check it yourself.

For example, Sportsters have the drive sprocket on the right while Big Twins have it on the left & last time I had a rear tire put on one of my Sportsters, the shop owner (40 years experience) put the tire on as if the wheel was for a BT. With the wheel laying in the floor & the sprocket facing up, if you're used to working on BT's all the time, it's easy to forget this wheel/tire is for a Sportster & the tire goes on the opposite direction.

That particular guy caught it right away - once the wheel was mounted, he saw that the tire was going backwards - but a lot of guys would miss it. So even if the one changing tires has a lot of experience, you still need to check it yourself - as has been mentioned, that arrow showing direction of rotation is there for a reason.

On a related note, it seems many Harleys & not just Sportsters come with the rear wheel off-center & that's another thing you should check. 1st time I went for tires for my '95 Sportster, the shop owner said go get that coffee-can over there on the shelf - it was full of axle spacers. At 1st glance they all looked the same, but they're not & indeed, my rear wheel was off to the right a little bit.

The same was true with my '00 Sportster & the shop owner said he kept that can of spacers because it is a common problem. I wondered why the bike felt a bit different in left & right turns & the rear wheel being off-center just a bit was why. A quick glance @ the bike from the rear may say the tire is centered, but it may not be & it doesn't have to be off much to affect the handling.

- Art

Thanks for that info Art, I'll ask Harley to check on my Sporty next time. I've notice a slight difference in feel when comparing left and right turns.

There was a discussion about that on another forum a while back - seems it's a "left brain - right brain" deal. And while right-handed people tend to turn left better, left-handed people tend to turn right better.

Check the axle spacers anyway 'cause the rear wheel may very well br off-center & one guy I know found his front wheel was off too - from the factory.

left turns over right turns is the fact that the throttle is on the right and the clutch is on the left, your throttle hand is used to doing most of the work, and the use of throttle to facilitate a turn is easier stretched out then right up and reverse angle closer to the body. the quad riders like thumb throttles for the opposite reason, and it has to do with trottle control also. of course abby would be the one to elaborate on this subject.