Tyre tread
 

Hi there people...

I was just looking at all the different types of tread available for cars and motor bikes, and was thinking how come on aircraft, the tread is always just straight lines?

Are straight lines the best pattern for dispersing water and providing the most amount of grip?

You got it in one!

Perhaps the fact that aircraft don't have to take corners at 90mph might be a factor as well.:8

Unless it's Ryanair! :E

Dispersing water is best done by those unidirection tread patterns. In dry conditions slicks give the best grip.

The aviation industry will catch up one day!

Which AFAIK are specific to each side of the vehicle...is it perhaps cheaper to have tyres usable on both sides of the aircraft?

South Coast/Someone else.
This is a huge subject, but simply put you’d think after all the research into wet weather tyre grip you’d have thought that if the tread design had been really significant then one design would long ago have shown itself more effective than others. Remember: Friction is independent of area, but directly dependant on weight.


In truth the issue of tread design is more about marketing than anything else. Wet weather grip is dependant on three factors.
1. The amount of weight carried by the tire.
2. The amount of, and depth of, the radial slots cut into the tire.
3. The compound of the rubber.

A. Most water is dispersed in font of the tyre, in fact the tire simply pushes it out of the way. The amount of weight carried by that tire will dictate to a large degree, how much water will be moved.

B. Whatever water is left is directed through the radial slots cut in the tire. The depth of those slots combined with the weight carried (and the roughness of the road surface) dictate the speed the tire can go before aquaplaning occurs.

C. The amount of ‘grip’ obtained from the rubber in actual contact with the surface of the road is dependant on the compound. Softer compounds better grip, harder compounds less grip.

Regards,
White Bear.

You got it in one!
 

The amount of weight carried by that tire will dictate to a large degree, how much water will be moved.

I disagree sir! If you want to be pedantic then .........maybe as the tyre footprint is larger with increased weight but everything else I agree with.

When I went to pilot school (1963) the formula was aqua/hydro plane speed equals nine times the square root of the tyre (tire) pressure. in knots

I remember watching a movie (B4 video) of hydro/aqua planing being demonstrated in a test facility through a glass plate underneath the tyre (Tire) footprint. Very interesting.

Thus for example while racing my old classic www.targaflorioteam.org in the wet I put as much pressure in the tyre as it would safely hold (Trade secret).

If you take a normal road car tyre, regardless of tread and put say 36 psi of tyre (Tire) pressure in it will give you a hydro/aqua plane speed of 54 Kts or 62 mph or 100 kph.

Believe me it works in torrential rain.

Chok Dee

Slicks are widely accepted as the best compromise for aircraft tyre treads and for racing cars on dry surfaces.

Aircraft tyre treads have dimples or grooves to let you see how much compound remains before you are down to the reinforcing top ply.