Direction on tyres

[1gear]

How cruical is this? I've got some Marathon plus tyres on the bike now. I've got a fixed fixed back wheel so obviously when I turn the wheel around the tyre will be the wrong way.
What's the direction for? How important is it? Will I notice a difference when I spin the wheel around?
In the past I don't think I've had one that had direction on it. The Conti Gatorskins did, but I never had those on the back wheel, always had cheap tyres that I could skid on and not bother about.

[Kim]

I believe the accepted wisdom is that unless it's a serious knobbly, where it may make a real difference to mud-shedding, "not very".

There may be a slight difference in rolling resistance that you'd have to do SCIENCE to detect.

[StuAff]

That's handy- not long fitted a Marathon to the back wheel of my Dahon Cadenza, only noticed a few days later it was on the wrong way round. Running just fine nonetheless.

[oncemore]

I accept the same wisdom as Kim.

[rower40]

Make sure the axis of symmetry of the tyre is at right-angles to the direction of travel of the bike, AND at right-angles to the vertical when travelling in a straight line.

HTH

[Chris S]

Just that scenario here - M+ on fixed wheel, sometimes reversed, Never ever noticed a difference. That's not to say there isn't one - just not noticed it.

[JohnP]

On motorcycle or car tyres the tread serves mainly to pump water away from under the tyre.  When reversed it would tend to suck water in rather than blow it out.  Increased risk of aquaplaning.  Daughter's car recently failed MOT because a tyre was on the wrong way round.  Actually the wheel was on the wrong side of the car after 3 visitations in 2 days.

On a bike?  Negligible.

[drossall]

It's not very important. You need the arrows in the tread pointing forwards for the reasons JohnP said - the leading edge of the arrow reaches the ground first as the wheel rotates. The arrow then spreads towards the outside of the tyre, taking the water with it.

However, tread isn't important on a bike (on the road), so getting it backwards isn't that important either.

[1gear]

Cheers all

[Cudzoziemiec]

I have some tyres on an MTB which are marked "Speed" in one direction and "Grip" the other way. I turned them round to get more grip and noticed the tiniest difference in mud and sand. None on tarmac.

[drossall]

Is that so you can go fast up hill and, if you slip, you don't roll fast back down again?

[PaulF]

Is that so you can go fast up hill and, if you slip, you don't roll fast back down again?

Some mtb'ers will have the front mounted for grip and the rear for speed, logic being that you want more grip at the front but can sacrifice some grip for speed at the rear

P.S. Noticed the

[Biggsy]

I think you'll find that it is The Law to have the bright red label on the right-hand side, if there is one.  It just looks Wrong to have it on the left.  Fortunately, the M+ has no such prominent label.