berninicaco3

I know car tires-- arrow points forward (viewed from the top), to channel water outwards from the center.
Oddly, at first, motorcycle tires point both directions. The back, holding all the weight and doing no turning, points forward. The front points backwards...
Here's a good photo of what I'm talking about
https://www.vikingbags.com/blog/wp-co...a-650-2012.jpg
https://www.listofimages.com/wp-conte...otorcycles.jpg
As a motorcycle person explained to me, when you corner, you only go on one half of the tire. A car tire NEVER leans like that, but when you visualize a motor cycle tire, "backwards" does indeed channel water outwards and behind the tire on turns! And it's on turns that you need traction on the front tire.

Strangely, here's a motorcycle with the front tire going the same directionality as the rear, so possibly incorrect...? you can appreciate why I'd be a bit confused.
https://hqpicsonly.com/motorcycle/suzuki-motorcycle.jpg


Preface complete-- for a bike tire, which I know less about, do I mount the front tire "backwards" like a motorcycle tire? The V pointing to the rear, as viewed from the top, for the front tire; and pointing forwards on the back tire?

On the other hand, there's not a whole lot of caster on a bike, is there? I won't be leaning into turns at 20mph, will I? Especially a commuter/comfort/hybrid like I've started to ride.
So maybe car-style is correct.


thanks for the clarification!
-Bernard

HillRider

Are you road riding or off-road? If road riding a bicycle tire is so narrow and so heavily loaded that it cuts through any layer of water on the road and "tread" has no effect. In fact, slick bike tires have better traction than treaded ones on a hard surface. Estimates are a road bicycle would have to be going 85 mph to start hydroplaning.

Off road, tread is there to give "bite" in soft surfaces like mud, sand and loose dirt. Channeling water means nothing.

So, no, it doesn't matter which way the tread points.

secretagent

It matters which way the logo faces

DiabloScott

This is especially true for slicks.

jimc101

Add to that where it is in relation to the valve hole

fietsbob

If rotation is in the designers head, it will have an arrow molded in the sidewall ,
if it doesn't matter it wont.

woodcraft

[astoundingly witty tire-tread-related comment here]

gregjones

Install it how you feel would make you most comfortable, after all, that's the most important (if not only) function of the tread at all......to make you feel comfortable.

FBinNY 

The biggest difference between bicycle and motorcycle tires ant those of cars and trucks are that their crowned, as opposed to presenting a flat surface to the road. The crowned (round) shape has to be there because 2 wheel vehicles lean and if there were a flat bottom it would resist that action (not to mention making handling very complicated).

The crowned surface of 2 wheel tires cuts through water like the bow of a boat so hydroplaning is much less of a problem, than it is when flat tires ski up onto a film of water. Hydroplaning is rare on motorcycles, and totally impossible on bike tires, so the water channels are useless.

Dirt bikes (both motor and pedal) also have directional tires, and here it's meaningful because the tires are designed to bite in one direction only. There's often also a difference between front tires designed to generate side traction for steering vs. rear tires which are for pushing only. Look at this picture of an old farm tractor to see an extreme example of the difference between tires designed for steering vs. pushing.

xenologer

How about?:
The only directionality that matters, is the rubber side faces out, and the fabric side faces in.

HillRider

And that the rubber side faces down.

jolly_ross

I have seen tyres with opposing rotation direction arrows depending on if it was to be fitted on rear or front. Do what fietsbob says.

(Although I strongly suspect that when it comes to directional tread the emperor has no clothes. It's not like you're laying down 50 hp, turning at 80mph, or weigh two tons.

In my experience rubber hardness, sidewall flexibility and tyre pressure matter)

pierce

you are leaning into ALL turns, whether you know it or not. if you didn't lean, you would fall over. The tires have to stay under the CoG of the bike+rider relative to its frame of reference... any change of direction causes that reference frame to tilt due to centrifugal force. take a pendulem, hold it out at arms length and slowly turn around a circle... see?


and yes what those other guys said about tread... on pavement, tread is purely cosmetic, a perfect slick would have better traction than any grooved pattern as more rubber would be on the road.

I always mount my tires with the color label on the drive side, and centered over the valve stem, and if the tire has any directional arrow, I follow it purely for consistency sake, and because the tread, such as it is, 'looks right' that way. being consistent like this can help when you're repairing a flat, as you can match the tire against the rim and tube to verify that whatever caused the puncture is gone. I probably should get in the habit of using a grease pencil or something to mark an arrow on the tube, too, heh.

Kimmo

I agree with all that except the potential exists for tyres to be designed well enough for direction to matter off road; anything front/rear specific probably falls in that category. Perhaps even a simple V pattern, reversed on the front for braking would be noticeably better one way.

I gather the softer the conditions, the more it matters. I can spin or slide out my road tyres quite easily on gravel, so traction is indeed an issue.

HillRider

Yes, off-road tread does indeed matter and the front tire has a different job to do than the rear so a directional tread is probably useful.

Also correct but the OP was asking about tread as a means of water displacement on a road bike and, there, it has no value.

bradtx

Bernard, Modern sport motorcycle front tires have the chevrons pointed to the rear (viewed from the top) to prevent cupping primarily caused by the crown of the road.

My mountain bike has directional tires. The front's chevrons point forward (top) and is reversed if going by the label from the rear's. I'm not absolutely sure it makes a difference.

Brad

Bezalel

How fast was Jobst Brandt riding when this photo was taken?

Andrew R Stewart 

That photo was from an ad for Avocet Fastgrip tires. The story goes (not shown in the photo) that Avocet got Jobst to don motorcycle leathers and ride his bike around a test pad that had been watered down to see how far the lean angle could be. Andy (who still uses Fastgrip tires on his tourer but doesn't lean anywhere as far).

DiabloScott

Right, and the point of the ad was that slick tires corner at least as ones with some kind of file tread. Avocet and Specialized both came up with slick tires about the same time and it was kind of a hard sell to generations of riders who thought the tread pattern helped somehow. It was also about the same time as kevlar beads and 120psi pressure ratings for clinchers and the end of the tubular dominance - the moon landing era for bicycle tires.

pierce

What ever happened with Avocet? my old road bike still sports an Avocet Touring III seat, was a great seat.

HillRider

They still exist but pretty much under the radar of most riders. I have their O2 Air 40 Men's saddles on all of my bikes and bought two replacements directly from them a couple of years ago so they were still around then. Their web site still lists saddles, tires and cyclometers but i don't know how recently it's been updated.

My first cyclometer, bought in 1986, was an Avocet 20, which was great and better than anything else at the time. Over the next few years I watched their prices rise and their quality tumble until I bought my first Cat-Eye and never looked back.

davidad

https://draco.nac.uci.edu/rbfaq/FAQ/8b.13.html