2022 Tyres Thread

[Holm86]

The other thing is that you don't want the disc touching wheel because when carbon rubs on magnesium it will cut through it like butter, within a lap you wont have a wheel left. So you've got to be a bit careful you don't push for a bit extra and end up losing your wheel.

Magnesium? What's the point in using magnesium when titanium is available? AFAIK titanium has the highest strength to weight ratio of metals.

Can you find an application of titanium to any motorsport wheels?

Aluminium, Magnesium, Carbon - these are your options if you are looking to purchase some.

Am assuming F1 regs discount Carbon wheels...so Magnesium is the way forwards.

Titanium is more that twice as dense as magnesium, and when you can make magnesium wheels that are strong enough I don't see any point in making them out of titanium?
And magnesium is much easier to cast/machine so its not worth the trouble.

[CMSMJ1]

Magnesium? What's the point in using magnesium when titanium is available? AFAIK titanium has the highest strength to weight ratio of metals.

Can you find an application of titanium to any motorsport wheels?

Aluminium, Magnesium, Carbon - these are your options if you are looking to purchase some.

Am assuming F1 regs discount Carbon wheels...so Magnesium is the way forwards.

Titanium is more that twice as dense as magnesium, and when you can make magnesium wheels that are strong enough I don't see any point in making them out of titanium?
And magnesium is much easier to cast/machine so its not worth the trouble.

Agreed

Our mate mzso was getting excited with Ti though so wanted to ask whether there were any applications - I know of none.

Even the sheels for the Bloodhound etc are Steel - which would mean Ti not suitable there too.. but that's a decent thread drift..

[BassVirolla]

Is not magnesium forbidden for use in rims? It's what rings a bell to me...

[djos]

Titanium is actually quite brittle, when close to peak loads, compared to other high strength materials.

[mzso]

Titanium is actually quite brittle, when close to peak loads, compared to other high strength materials.

And that includes all (useful) alloys?

[djos]

Titanium is actually quite brittle, when close to peak loads, compared to other high strength materials.

And that includes all (useful) alloys?

Aluminum and many other alloys will deform before they break, titanium tends to simply break.

Titaniums big benefit is strength while subjected to very high temps.

[Ringleheim]

Looks in to join discussion about wheel size...finds argument about titanium and its relative strength and God knows what else...quietly moves on to something else.

It's mostly about arguing here, isn't it? And at all chat forums.

LOL

[FW17]

Looks like car weight is increased by 3kgs for next year, will this weight and safety loop ever end?

[Stu]

Looks like car weight is increased by 3kgs for next year, will this weight and safety loop ever end?

1000 is a nice round number

[mclaren111]

Looks like car weight is increased by 3kgs for next year, will this weight and safety loop ever end?

Agreed... It's beyond ridiculous... Same goes for the length...

[henry]

Looks like car weight is increased by 3kgs for next year, will this weight and safety loop ever end?

1000 is a nice round number

Almost there. Static mass is now set at 795 kg. Add 110kg for fuel. We just have to find 95kg. If we’re only looking at acceleration and braking then we can add to that a mass representing the rotational inertia of the wheels and tyres. Years ago I calculated the 13” wheels at about 60kg equivalent and a rough extension of that for the 18” wheels gets to 90kg. Just 5kg to find. Can we add the drinks bottle?

[JordanMugen]

So you're implying Mg is stronger considering the loads a wheel gets?

No, rather titanium alloy is not a suitable material for a wheel (racing or otherwise), else it would be used. Instead we have:

Steel < Aluminium Alloy < Magnesium Alloy < Carbon-Fibre
[In order of increasing cost.]

You are welcome to set up a foundry to sell titanium alloy wheels!

I suspect the problem is that once you manufacture the barrel of the titanium alloy wheel at 1/3rd the thickness or less of the magnesium alloy wheel (to obtain the weight-saving from titanium's greater shear/tensile strength as you say), you no longer have a profile with sufficient stiffness and rigidity? But I'm just guessing.



I doubt that the likes of BBS, OZ Racing, Rays and so forth simply lack the data to realise they should have been making their racing wheels out of titanium alloy and not magnesium alloy all along! Titanium alloy racing wheels must therefore not stack up.

Edit: It seems the modulus of elasticity of titanium alloy is about 2.5x more than magnesium alloy, the tensile strength is 4x more, but the density is 2.4x more. So you could make the titanium alloy wheel barrel about 1/2.5x the thickness to obtain the same stiffness as the magnesium alloy wheel but it would weigh about the same anyway while the wheel manufacturers have foundries and tooling for aluminium alloy and magnesium alloy wheels (which are quite similar), not titanium alloy wheels that would need to be made much thinner using different processes.

TL;DR: The non-use of titanium alloy in racing wheels seems to be due its mediocre modulus of elasticity, rather than its extremely high tensile strength... Given the modulus of elasticity, titanium alloy offers no advantage over magnesium alloy.

what we call strength-to-weight-ratio is assuming direct loads - not bending loads etc

So you're implying Mg is stronger considering the loads a wheel gets?

Perhaps more stiff as opposed to stronger? Particularly in torsion, perhaps? The shear or tensile strength of the monocoque or wheel is not really the main concern, one presumes, but rather rigidity.

[Stu]

Looks like car weight is increased by 3kgs for next year, will this weight and safety loop ever end?

1000 is a nice round number

Almost there. Static mass is now set at 795 kg. Add 110kg for fuel. We just have to find 95kg. If we’re only looking at acceleration and braking then we can add to that a mass representing the rotational inertia of the wheels and tyres. Years ago I calculated the 13” wheels at about 60kg equivalent and a rough extension of that for the 18” wheels gets to 90kg. Just 5kg to find. Can we add the drinks bottle?

Are energy/electrolyte drinks heavier than straight water?

You could also mandate a cool-vest…

Bingo!!!

[JordanMugen]

Looks like car weight is increased by 3kgs for next year, will this weight and safety loop ever end?

1000 is a nice round number

Can be achieved with a road-relevant supersized battery pack.

I would propose 1250kg or more even for maximum relevance to road-going EV sportscars like the Porsche Taycan which tend to have large batteries and be quite heavy (or pick-up trucks like the F150 Lightning for that matter). Formula E seems to be diverging from road relevance with its insistence on small battery capacity, which is just not representative of the popular EVs in the real auto market (and doesn't allow for 305km race length at maximum power either).

Any EV, even a sportscar, that launches with a small battery and low range gets savaged by negative comments in the marketplace. EV enthusiasts expect a supersized battery and large range it seems.

[Stu]

Looks like car weight is increased by 3kgs for next year, will this weight and safety loop ever end?

1000 is a nice round number

Can be achieved with a road-relevant supersized battery pack.

I would propose 1250kg or more even for maximum relevance to road-going EV sportscars like the Porsche Taycan which tend to have large batteries and be quite heavy (or pick-up trucks like the F150 Lightning for that matter). Formula E seems to be diverging from road relevance with its insistence on small battery capacity, which is just not representative of the popular EVs in the real auto market (and doesn't allow for 305km race length at maximum power either).

Any EV, even a sportscar, that launches with a small battery and low range gets savaged by negative comments in the marketplace. EV enthusiasts expect a supersized battery and large range it seems.

Well F1 cars are about the size of an F-150…

They are fairly commonly fitted with 18” wheels!





(…and now we are back on-topic!! )