Chevron tread pattern – which way round?

I have acquired some part-worn Crazy Bobs for my #2 hack bike
lol

There are no rotation arrows. Would you put them on with the chevrons pointing

a) Forwards
b) Backwards
c) Forwards on the back, backwards on the front
d) Forwards on the front, backwards on the rear
e) DGAS

If the blocks are ramped then the ramp should hit the ground first.

I’m trying to work out which way the chevrons shoudl point when they touch the ground for optimum water dispersal.

Nope, can’t do it.

Buy tyres with a block tread is my advice.

I’ve always been under the impression it’s point hit the ground first to push the water outwards as they make more contact.

Chevrons forward normally

a

(assuming you mean pointing forwards at the top of the wheel, of course… let’s not get into the horrors of the pedal thread thread again)

Though with off-road tyres (where it’s a matter of knobs digging in rather than sipes clearing water) I’ve often gone for d.

Then again, on tarmac there’s a sound argument for e. But even then, they have to go one way round or the other, so on aesthetics grounds you’d go with a. Unless you’re weird.

I’m trying to work out which way the chevrons shoudl point when they touch the ground for optimum water dispersal. Nope, can’t do it.

It’s chevrons forward (at the top), then the water gets squeezed out towards the sides as the tyre rolls into it, rather than being pushed into the centre of the tyre. But with a bicycle tyre it’s not the issue it is with car tyres.

My money would be on it not making any difference, but I’d fit them pointing forwards because that looks right.

Decades ago I read that the tread patterns on car tyres are mostly to try and reduce tyre noise and the pattern itself doesn’t really make any difference to water dispersion. I’ve always wondered how much truth there was in it. F1 rain tyres seem to have curvy patterns, so the tyre manufacturers obviously do that for a reason, but it’s not obvious to me how that shape channels water more effectively than straight grooves.

Maybe they end up with larger blocks of rubber with the curved sipes and these large blocks better transmit heat to the rest of the tyre carcass and are then less likely to heat up and break down on a drying track?

Curves of some description make sense because, while the tyre is hitting the ground at (to all intents and purposes) a constant rate, the water is being accelerated sideways, so it makes sense that if you start squeezing it out from the centre then the sipes should be roughly longitudinal near the centre and more transverse at the edges.

Add to that, as above, heat management is a major issue with F1 tyres so the tread will be influenced by this—and it’ll be influenced by aerodynamics as well as hydrodynamics. There will be other influences as well: eg with F1 tyres I’d imagine there will be more water ejected as outwash rather than sent towards the body, whereas on road cars (which have closed wheels and no real aero considerations) that would tend to increase ambient spray, which would reduce visibility for following vehicles.

My guess is that it will be accelerated forwards much more energetically than sideways, if you look at it from the frame of reference of the water. But then, everything’s probably upside down from that perspective, so I’m confused.

They’re not chevrons they’re sipes.

Front Tyre – Chevron forward looking from top for better steering.
Back tyre – Chevron backwards, for better drive.

At least that was always my thinking from days when we had proper front and rear specific tyres.

Think of tractor tyres, or if your old enough farmer johns. So sitting on the bike looking down at the front tyre they should be pointing the forwards. Same on the back.

So sitting on the bike looking down at the front tyre they should be pointing the forwards. Same on the back.

This is how I’ve always done it. And don’t turn the back around, you need braking on the back tyre too.

In addition to chevrons forward as per my earlier post, I noticed that my car tyres, front and back, are chevrons forward too 😀

Pointy end into the ground first would be less draggy, wide end first would tend to prevent bogging down on mud etc

Also, WTAF is that?!

That’s the most blatant case of mechanical doping I’ve ever seen.

Based upon motorcycle tyre design and rotation arrows, option C.
The large opening of the sipes on the front allows more water or debris to clear, and at the rear drag is reduced by the block leading.
Bear in mind that the rear tread isn’t having to clear as much water due to the front tyre having already done the vast majority.

This is how I’ve always done it. And don’t turn the back around, you need braking on the back tyre too.

Definitely. Unless you are Mark Cavendish with drum brakes you can (and could need to in an emergency) brake far more rapidly than you can accelerate.

** the picture has now loaded for me, I see you do have drum brakes, and the bike probably looks like it is for tarmac only. So braking fairly irrelevant to tread pattern.

Still forwards for water clearance for anything bar thick gloopy mud.