Tire Question

[Samelak]

Just bought a set tires for my 80 at the stock size and saw that my rear tire is marked as a front on the sidewall. I waited forever to get these here in Okinawa. Will there be any problems using it as a rear tire?

[EMS]

It probably depends a lot on how you ride. Most times front tires have a different tread pattern to provide more lateral grip when turning while rear tire tread provides more rotational grip. I don't think you should have a big problem as long as you are aware of what you have. What does the tread look like?

[Samelak]

It's a front metzler lasertec. Has a v pattern with the open end of the v moving in the front. I'm probably going to order another tire, but will use the current one until it arrives.

[steve murdoch icoa #5322]

Can't speak from experience but from what i have seen and read over the years using a rear on the front{if the pattern is the same] is acceptable but not the other way round. I can't imagine it would last very long.
Similar to what Mike was saying, the front tire is designed to be pushed and some steering input. Asking it to do otherwise might be too much.

[Rick Pope]

As Mike pointed out, fronts have different tread patterns for a reason. If that front is the one I'm thinking of (ME 33?), it has small tread blocks, which will distort under acceleration, thus causing faster wear. The old ME 88 is a good match for the rear.

Fronts typically have more siping to get the water away from the tire, while rears have less in the middle, because the front has already cleared the path. When you're leaned over, the tires don't follow exactly the same track, thus more side siping on rears.

[EMS]

Here is a side by side comparo of the Lasertec rear and front



I am curious what size tire you ordered and what rear wheel you are running. The widest 18" front supposedly is only 110 and the widest 17" is only 120.
If your rear wheel is wider than 2.50, this would be my major concern

[rpleines]

For what it’s worth.

1.From Maxxis website
Tires marked as front or rear tires should only be used in their designated position. Correct matching of front and rear tires is critical to obtaining optimum performance and handling.
Front and rear tires have different handling needs. A front tire has a more triangulated profile for steering control, while a rear tire has a flatter profile for bike stability. Using a tire in a position for which it was not designed will result in reduced handling capability, putting the rider in danger.
Combining a new front tire with a worn rear tire or vice versa may cause instability. Always consult your vehicle’s manufacturer before modifying your motorcycle’s tires from stock.

2.From Dunlop website
Front and Rear Tire Matching
Remember, the correct matching of front and rear tires is important to obtain optimum performance and handling. Follow the Tire Selection guidelines.
Mount only tires marked “front wheel” on the front position and only tires marked “rear wheel” on the rear position.

3.From Bike talk
Front tire on rear of bike
I just spoke to the MFG [Metzler] about my situation[ mounted front tire on rear]. He said this is a common mistake made by some shops. He also said to change it because it can be unsafe with the wrong tire in the rear. The weight capacity of the tires is different and that alone is cause for concern. I will stop by the shop that did the work and see what they have to say.

4.From Motorcycle Industry Council Tire Guide
Your motorcycle was designed to work in harmony with a limited
selection of tires. The owner’s manual will specify tire size, construction
(radial or bias, tube-type or tubeless), load range, and speed
index, and may identify the brand installed as original equipment. In
addition, tires are specifically designed for use only on the front or rear
wheel – because each tire has a different function – and the front and
rear tires should match each other by being from the same brand and…

5.From Ninja250Wiki
Can I put a front tire on the rear?

No. Don't do it. It's a bad idea.... This question comes up when someone wants to get a particular tire, but it's only made as a front in, say, 130/90-16. It's still the same size, so it sounds OK - but it's not. A front motorcycle tire is designed specifically for the front. Tires are directional for a reason. That reason is for the dispersal of energy. A front tire works on energy from braking and the rear on energy from accelerating. Tires are "wrapped" (for lack of a better term) and can come apart if pushed in the wrong direction. It's like trying to find the end of a roll of tape: Run your fingernail one direction and it just pushes the end into the roll and slips off the end. Run it the other way and your fingernail catches the tape and pulls it up and away. So, to run a front tire on the rear and not run into a delamination issue, you need to flip it around backwards. But, by doing that, you 100% negate all the water dispersing properties of the tire. Fronts also have a rounder profile and shallower tread, so they won't last as long and won't handle as well as one designed for the rear.
And to anticipate the next question: Putting a rear on the front is even worse.

[EMS]

I think we all agree that it is not one of the smartest things to do, but it may be O.K. to keep the bike on the road while waiting for the correct tire.
I would be very careful with the recommendation in the quote from Ninja20Wiki, however. I am not sure were he really comes from but "flipping the tire around to avoid delamination"....
If the bike accelerates, the tires front and rear see the same energy input. They both want to increase rotational speed against resistance from the road surface.
And during braking, it is the same. What happens to the rear tire when you use the rear brake as opposed to what happens to the front tire when you use the front brake??
Assuming that flipping the tire when used in the wrong position makes it experience the same "rotational" environment as if used in the correct position, is quite a stretch. IMO

[rpleines]

This may help? There are fleeting moments when I think I understand it.

Tires Directional Arrows Explained By Avon Tyres
"Before we can talk about directional arrows you must first understand a bit about tread patterns. There are many different tread patterns but there is one main reason to have any tread and that is to disperse water. (dust, dirt)
A tread pattern can be designed to disperse more water by making it rotate in only one direction. Thus, the need for directional arrows. The arrow tells you which way to mount a tire for maximum water dispersal. Another, less apparent reason for directional arrows is the tread splice.What is a tread splice? When a tire is manufactured the tread portion of the tire starts out as a long flat strip. This strip is wrapped around the tire and the two ends are cut on an angle so one end overlaps the other rather than having square cut ends.
This overlapping point or splice offers a bigger surface area to bond together, rather than the small surface area provided by square cut ends. (Imagine gluing your fingertips together, as opposed to gluing along the entire length of your fingers laid on top of each other. Like an angled splice, the overlapping fingers result in a much stronger bond).
To further ensure the strength of this bond along the tread splice the directional arrow will show you which way to mount the tire so that when the rider is “on the gas”; the acceleration force on the rear tire is pressing the splice together, rather than peeling it back.
]As for braking, 80 % of the braking should take place in the front on most bikes. Therefore, the front tread splice is run in the opposite direction than that of the rear, so when the rider is on the brakes, he’s not peeling the tread splice back.
If you are using a tire that has a directional arrow for rear rotation only and for some reason you want to put it on the front, make sure it is rotating in the opposite direction so you don’t aggravate the tread splice.]Avon Tyres."
- See more at: http://cyrilhuzeblog.com/2009/08/23/tir ... nnvFg.dpuf

[EMS]

Nice explanation for sure..,,,But I still don't understand it. A bike has both rear and front brakes. And why you will aggravate the tread splice of the rear tire when mounting it on the front..???? Just shows that tires are a science of their own.

[Rick Pope]

Remember the old days, when we ran the same tire front and rear? Think Dunlop K81, or that era. Many tires had arrows on each side, one indicating front rotation, and on the other side, opposite rotation for the rear.

Last time I ran into that was probably 15 years ago, maybe more. I'm thinking it was a Dunlop 591, back when that was a premium sport tire.

[Samelak]

I threw my old tire back on until the new one arrives. It still has tread, so it will be good for a little while longer. No point chancing it since the roads are slick here. They are made with crushed corral.