Directional tread pattern

[Steve Malkin]

Whilst giving the bike a clean today I noticed that my front tyre was on the wrong way round. It's the type that has a directional tread pattern a bit like this:

It's supposed to be fitted with the arrows in the pattern facing in the direction of wheel rotation, but I had it on the other way round

It must have been like that since the last time I had the tyre off to fix a puncture which was months ago, and I can honestly say that I hadn't noticed the slightest difference in the way the tyre felt or performed.

Anyway I swapped it back round, because I think it just looks nicer with the arrows pointing forwards, but what difference if any does it really make?
Am I lucky to be alive having ridden for months on a tyre that could have exploded at any minute or was I simply guilty of crimes against cycling aesthetics?

 

[Milo]

It almost defiantly does not really matter. It certainly is not dangerous anyway.

 

[BSRU]

If a tyre needs to be fitted a certain way around, it normally has "direction of rotation" indicator on the side wall. Some tyres such as the Conti GP 4 Seasons can be put on either way, it makes no difference.

 

[Norm]

Physics suggests that the direction arrows should be reversed on front wheels, so you had them right before.

 

[youngoldbloke]

I was told it is not so much to do with the tread pattern (if any) on a slick road tyre, but relates to the construction of the tyre casing.

 

[Night Train]

The theory, as far as I see it, is that seen from the top the chevron pattern should point forwards (direction of rotation) of the driving wheel, and backwards (against the direction of rotation) for a non driving wheel.

Mine all point in the direction of travel as it looks better.


I have seen some, mainly MTB tyres, that specify different direction depending on front or rear fitment.

That should be to do with the self cleaning of tread patterns. The chevron shape would push mud out of the tread and to the sides on the drive wheel when it slips in the driving direction, but for the non driven front wheel it will push mud from the tread out to the sides when it slips during braking. Thus the treads are kept clear of mud when driving and braking respectively.
At least that is the theory with motor vehicle directional off road tyres.

 

[sidevalve]

I was told it is not so much to do with the tread pattern (if any) on a slick road tyre, but relates to the construction of the tyre casing.

This is true of vehicle ['specially m/cycle tyres] where the reinforcing belts and construction are designed for one way rotational forces however IMHO on a cycle the forces are so tiny in comparison only the tread pattern may have a small effect.

 

[Norm]

As NT says, it's about the force against the ground keeping the cleats clear of mud. At the front of the bike, the ground pushes the tyre round so the V should point forward at the bottom of the tyre's rotation. At the rear, the tyre is pushing against the ground so the V should point backwards.

However, again as NT says, that looks weird and you'll always find someone to tell you that your tyres aren't fitted correctly and, as sidevalve suggests, there isn't much difference when cycling, so mount them both the same way as the cleats are unlikely to get that clogged unless you are heading for pretty extreme conditions anyway.

 

[grumpyoldgit]

Car racing slicks are directional,so therefore to do with construction rather than tread.On the driven wheels,usually the rear,the tyres rotate in the direction of the arrows,on the slave,or non driven wheels,the arrows point the wrong way.No idea why,but the tyre suppliers always fit them up this way.Never bothered to ask.

 

[Steve Malkin]

Thanks for all the replies - it's been an education for me, I never realised there was so much to it!

On closer inspection, the tyre did have a marker on the sidewall to show the fitting direction, so I
dont really have any excuse for getting it wrong.

I suppose if the manufacturer (schwalbe) thought it was important enough to put that on then there must be some good reason so I'll take a bit more care in future.

I won't lose any sleep over it though...

 

[biggs682]

i cant imagine at bike speeds its going to make much difference but you never know .

i can see it would make a difference in water dispersion hopefully

 

[Matthew_T]

i can see it would make a difference in water dispersion hopefully

Yes thats what I thought. After the tyre has met the wet ground, when it is returning to the brake area, the water is supposed to trickle through the grooves and disperse.
That it with grooves treads though. Slicks are of no use in the wet.

 

[ianrauk]

Yes thats what I thought. After the tyre has met the wet ground, when it is returning to the brake area, the water is supposed to trickle through the grooves and disperse.
That it with grooves treads though. Slicks are of no use in the wet.

You still have a lot to learn young man.
Slicks are better in the wet then tyres with tread as there is more contact with the road.
And as for aquaplaning...see Mr P's post above.

 

[Matthew_T]

[QUOTE 2132807, member: 45"]Bike tyres can't aquaplane. Tread on road bike tyres is therefore pointless and nothing more than a marketing gimmick.[/quote]
I beleive it gives you an awful lot more grip off road though?

 

[Norm]

I beleive it gives you an awful lot more grip off road though?

Only if the tyre has deep cleats will it make any difference off road. The tread of a road bike tyre is unnecessary (at best) on the road and useless off it.