Which way does the tire tread go?

[DSXMachina]

I'm confused. I've seen the same tires mounted differently. I recently bought the Michelin 6 Road tires, front and rear. They are marked on the sidewall with an arrow and a "Front" on the front tire and an arrow and a "Rear" on the rear tire.
Each tire is marked in two places so that when one arrow is at the top it faces one direction, and the one at the bottom faces the opposite direction. I have to assume that I should follow the arrow which is in place at the top of the tire and is therefore not upside down. Same with the rear.
My problem is that this then results in one tread facing opposite the other! What I mean is that the grooves in the front tire converge as the tire rotates, the grooves in the rear tire diverge as the tire rotates. I have seen different photos with the tires not matching the other photos. The way I would do it is like how Michelin shows the tires in their ads, but I want to be sure that's right.
Why can't the tires just have an arrow with "Rotation" direction clearly marked on the sidewall like performance car tires do?

 

[kbasa]

It only rotates in one direction according to the arrows, so use either one. Of course the one at the top is going to point in the opposite direction of the one at the bottom.

 

[RadioFlyer]

The "front" and "rear" merely tells you what application the tire is designed for. They are not to be read together with the arrow. The arrow indicates the direction of rotation.

 

[SCOUT6]

but, that is not right

Went to get my bike with its new shoes. The arrows on the tires were pointed towards one another. Told him that at least one of them was wrong.

 

[dravnx]

Went to get my bike with its new shoes. The arrows on the tires were pointed towards one another. Told him that at least one of them was wrong.

That is so easy to do. I have an automatic tire machine in my garage and I've put tires on backwards more then once. It's especially easy to do if someone else removed the wheel off the bike.
One time a buddy brought me his wheels and tires to change. I pulled the old tire off, grabbed the new tire and laid it on top of the wheel. Thought it through, my brain is turning, ABS wheel in on the left, wheel goes in this direction so tire must be mounted in this direction. I looked over at my bike to confirm as we both have the same bike. Nope, something wasn't adding up. Went through the thought process again, confirmed that I had it figured out, looked at my bike and nope, something is wrong. Turns out I've been riding on a backwards front tire. Good thing I didn't have to ride in the rain.

 

[Moretti]

The Michelin Road tires, and many others, are designed with the tread in opposite directions (front/rear) and are meant to be mounted that way. It’s to prevent hydroplaning in wet conditions.

 

[DSXMachina]

The "front" and "rear" merely tells you what application the tire is designed for. They are not to be read together with the arrow. The arrow indicates the direction of rotation.

Ah, I see. I should not have thought they went together! Thanks for the clear and concise explanation!

 

[Moretti]

Ah, I see. I should not have thought they went together! Thanks for the clear and concise explanation!

I had the same concern when I had new Road 5’s installed last year.

 

[kbasa]

That is so easy to do. I have an automatic tire machine in my garage and I've put tires on backwards more then once. It's especially easy to do if someone else removed the wheel off the bike.
One time a buddy brought me his wheels and tires to change. I pulled the old tire off, grabbed the new tire and laid it on top of the wheel. Thought it through, my brain is turning, ABS wheel in on the left, wheel goes in this direction so tire must be mounted in this direction. I looked over at my bike to confirm as we both have the same bike. Nope, something wasn't adding up. Went through the thought process again, confirmed that I had it figured out, looked at my bike and nope, something is wrong. Turns out I've been riding on a backwards front tire. Good thing I didn't have to ride in the rain.

Before I remove the wheel, I like to stick some blue tape on the rim with an arrow pointing in the direction of rotation. Some wheels in my garage have the arrows already cast into them, so check for those and make sure those arrows and the ones on the tire point in the same direction. I wanna say my hexhead and my VFR both have that. A little Sharpie arrow action on the mounting flange can be useful too.

 

[DSXMachina]

The Michelin Road tires, and many others, are designed with the tread in opposite directions (front/rear) and are meant to be mounted that way. It’s to prevent hydroplaning in wet conditions.

I sell car tires as part of my business. 100% of car tires, when they have angled grooves, have the grooves arranged so that as the tire rotates any water in a groove is channeled to the edge, not to the center. I was surprised to see the opposite on my Michelin front tire.

 

[dravnx]

Before I remove the wheel, I like to stick some blue tape on the rim with an arrow pointing in the direction of rotation. Some wheels in my garage have the arrows already cast into them, so check for those and make sure those arrows and the ones on the tire point in the same direction. I wanna say my hexhead and my VFR both have that. A little Sharpie arrow action on the mounting flange can be useful too.

I've since started marking the rotor with an arrow using a fat sharpie.

 

[lee]

I've since started marking the rotor with an arrow using a fat sharpie.

I do the same with the front tires and also write our names since I take my tires and Deb's tires in the same time.
I always show the guy I go to for tires the rotation arrow on the back wheel.
Our new bikes have gloss black wheels and I noticed the rotation arrow on the back wheel is hard to see.
On those back wheels I'll use blue painters tape with a arrow.

The guy we buy tires from always has me double check the tires are corrected mount before I leave the shop.

 

[tsconver]

Ah, I see. I should not have thought they went together! Thanks for the clear and concise explanation!

It is actually not just for rain it is for all condition traction. The rear tire is driving the bike forward so the tread is pointed in the direction to aid traction going forward. The front tire predominantly provides stopping power so the tread is opposite to give maximum traction when braking.

 

[dduelin]

I sell car tires as part of my business. 100% of car tires, when they have angled grooves, have the grooves arranged so that as the tire rotates any water in a groove is channeled to the edge, not to the center. I was surprised to see the opposite on my Michelin front tire.

Michelin front and rear tires have been like this for a long time and your observation of the front siping pattern is often mentioned. Car tire and MC tire contact patch shapes are very different and the long tapered or sausage shaped MC tire contact patch is much less likely to hydroplane to begin with and when the bike leans the sipes become diagonal across the patch. Apparently Michelin's "backwards" siping designs seen on their tires are the result of years of design, testing, and empirical experience because no brand I have ever tried is so confidence inspiring in the rain starting with 1st gen Pilot Roads through Road 5s. I have not tried Road 6s yet.

 

[DSXMachina]

Michelin front and rear tires have been like this for a long time and your observation of the front siping pattern is often mentioned. Car tire and MC tire contact patch shapes are very different and the long tapered or sausage shaped MC tire contact patch is much less likely to hydroplane to begin with and when the bike leans the sipes become diagonal across the patch. Apparently Michelin's "backwards" siping designs seen on their tires are the result of years of design, testing, and empirical experience because no brand I have ever tried is so confidence inspiring in the rain starting with 1st gen Pilot Roads through Road 5s. I have not tried Road 6s yet.

Thanks for that info. It would be interesting to learn what Michelin found during their testing.

 

[DSXMachina]

It is actually not just for rain it is for all condition traction. The rear tire is driving the bike forward so the tread is pointed in the direction to aid traction going forward. The front tire predominantly provides stopping power so the tread is opposite to give maximum traction when braking.

That makes sense to me. Thanks.

 

[cabnfvr]

That makes sense to me. Thanks.

Actually that would be wrong. Off road tires are the exception. On a road tire the tread is for water only. Nothing else.

 

[dduelin]

It is actually not just for rain it is for all condition traction. The rear tire is driving the bike forward so the tread is pointed in the direction to aid traction going forward. The front tire predominantly provides stopping power so the tread is opposite to give maximum traction when braking.

Tread pattern has little to do with dry braking and powering on the street. Tires with the most traction for braking or propulsion on dry surfaces have no tread design whatsoever. They are slicks. If the road and tire are dry the maximum coefficent of friction comes from 100% contact of tire to road. Because tires may encounter water on the road surface they have to have channels to displace the water. Michelin has evolved tread designs that had reservoirs that stored water until the tire surface lifted clear (Pilot Road 3s and 4s) to designs that keep the channels able to pass the same amount of water as the tire wears instead of traditional channels that get smaller smaller in volume and less able to move water as the tire wears (Road 5s and 6s). Thus the tires are able to generate similar amounts of dry and wet traction at mid to end of life as when the tires were new.

 

[r0ckrat]

Tread pattern has little to do with dry braking and powering on the street. Tires with the most traction for braking or propulsion on dry surfaces have no tread design whatsoever. They are slicks.

This is true as long as the surface is clean. Add a little dust, sand, or fine gravel, and you will definitely have better traction with some sort of tread pattern unless the tire is super soft (hot slicks), in which case they won't last long.

 

[dduelin]

This is true as long as the surface is clean. Add a little dust, sand, or fine gravel, and you will definitely have better traction with some sort of tread pattern unless the tire is super soft (hot slicks), in which case they won't last long.

Not so. Street or track tires develop grip through rubber's properties of indentation and molecular adhesion. Debris on the paved surface interferes with the tire completely touching the road surface and limits molecular adhesion but unless the road surface is composed entirely or primarily of dust, sand, or fine gravel a tread pattern doesn't prevent the tire from sliding on the debris lying on the road's surface. Think of dust, sand, fine gravel as ball bearings and tread is of no help gripping the ball bearings.