How stiff are F1 tyres?

[Jersey Tom]

Not one ply.

[strad]

I don't know for a fact, but I don't know why they would be more than 1 ply..the old Pirelli P7s had one ply sidewalls with 2 ply tread and they were for the road.

[Jersey Tom]

Some consumer tires are monoply, yes.

Almost guarantee F1 slicks are nowhere near radial with plies. As such, you need at least one other ply to balance things out.

Plus there's the need for responsiveness... load capacity.. etc etc.

[strad]

P7s were radials

[strad]

I don't know,,this video would imply 5 or 6 plys,,,I seriously doubt that due to heat build up and retention,,I wonder..A quick search didn't reveal much more than the video..
[youtube]http://www.youtube.com/watch?v=FjBZejP6oTk[/youtube]

[Jersey Tom]

My guess would be two plies, two belts, overlay, maybe a sidewall insert.

Pretty standard.

[DaveW]

Most tyres I "see" on a multi-post rig (usually cold, pressurized by the team & with static + 100-160 kph of down-force) increase vertical stiffness with increasing pressure and down-force.

That is not always the case, however. Some, usually low profile & designed for high down-force vehicles, decrease vertical stiffness with increasing pressure. Suggests that the sidewalls can contain serious support.

[marcush.]

Most tyres I "see" on a multi-post rig (usually cold, pressurized by the team & with static + 100-160 kph of down-force) increase vertical stiffness with increasing pressure and down-force.

That is not always the case, however. Some, usually low profile & designed for high down-force vehicles, decrease vertical stiffness with increasing pressure. Suggests that the sidewalls can contain serious support.

saw this on DTM tyres .they did not respond to pressure changes really ...wich was amazing ..unfortunatelly the car was not producing any downforce worth speaking of so ...

[ubrben]

Most tyres I "see" on a multi-post rig (usually cold, pressurized by the team & with static + 100-160 kph of down-force) increase vertical stiffness with increasing pressure and down-force.

That is not always the case, however. Some, usually low profile & designed for high down-force vehicles, decrease vertical stiffness with increasing pressure. Suggests that the sidewalls can contain serious support.

saw this on DTM tyres .they did not respond to pressure changes really ...wich was amazing ..unfortunatelly the car was not producing any downforce worth speaking of so ...

I wouldn't use DTM tyres as a reference - grossly undersized for the loads being asked of them...

Ben

[mep]

I just stepped over that and think you might see it:
http://www.motorsport-total.com/videos/f1/2880
(after commercial)
Sorry that it is in German, the most interesting point they said is that pressure makes up to 70% of tire stiffness.

[speedsense]

Was it on a rim and inflated with air? ...now that I would like to see...

Carbon fiber isn't stiff at all until epoxy is applied....

What ya smokin? I'm talking about the tire alone by itself..The guy could just wad it up ...one ply shìt that.
Carbon fiber is basically laid up like fiberglass

In a tire with carbon fiber cords, the carbon is not laid up with epoxy, as it's strength is in preventing elongation of the cords. The strength of the ply is some 10 to 30 times of a similar steel belt.
Fill it with air on a rim, and the strength goes way up. Though the carbon sheet the cords are made from would make a comfortable shirt to wear.IMHO

[strad]

WHat do they say? 1 pound of pressure equally a 30 pound change in the spring rate? You can see how come even a quarter of a pound is used to make a difference.

[speedsense]

WHat do they say? 1 pound of pressure equally a 30 pound change in the spring rate? You can see how come even a quarter of a pound is used to make a difference.

Depends on tire type and construction of the tire. I've seen some tires that increase with 1PSI, 50lbs and another of the same tire with different construction with 70lbs per 1 PSI.

[DaveW]

Depends on tire type and construction of the tire. I've seen some tires that increase with 1PSI, 50lbs and another of the same tire with different construction with 70lbs per 1 PSI.

Quite correct. It is surprising how often 50 lb/in/psi works, however, across a broad range of tyres.

A word of caution. Increase tyre pressure by 5 psi. Wait 5 mins. Decrease pressure by 5 psi. Wait 5 mins & then check. The pressure is likely to be wrong by around 1 psi.... The sign of a good truckie (still the default tyre man) is one who always checks (again) after setting pressures.

[strad]

You guys spend a lot of time trying to pick fly --- out of the pepper