Thread: Tyre Profile

Well one is missing tread and the other isnt so of course the used tyre will lose height ?

[QUOTE=loanrangie;1831709]Well one is missing tread and the other isnt so of course the used tyre will lose height ?[/QUOTE

I'm asking about the profile ,shape of the crown, worn more in the centre,not the diameter of the tyre. .W.

I wouldn't think so. Too many variables in the way the used tyre wears.

Edit: and if you used to run them above recommended pressure that would tend to wear the center of the tyre more - giving the reduction in profile you have shown.

Steve

Originally Posted by B.S.F.Nut

If run at correct pressure ,should an identical used and new tyre have the same profile ? Tyres are 7.00-16 8Ply rating Recomended pressure 25lbs. I used to run the used tyre at 27 lbs. .W.

Originally Posted by loanrangie

Well one is missing tread and the other isnt so of course the used tyre will lose height ?

Originally Posted by B.S.F.Nut

I'm asking about the profile ,shape of the crown, worn more in the centre,not the diameter of the tyre. .W.

I gather you mean the part that should be in contact with the road. In theory it should have the same 'profile' albeit somewhat shorter.

If a tyre is worn more in the middle it is a sign of over inflation. Having said that I would not have thought 2psi would make much difference.

What's the tyre construction?

The size looks like a crossply, which run at lower pressures than radials. If the pressure's too high, the tread area crowns - blows up like a balloon - & wears in the centre.

A radial of course has reinforcing under the tread to keep it relatively flat.

But the pic looks more like a radial tread pattern, so I'm not sure what's going on.

Regards
Max P

These days most people are used to radials, where it takes fair bit of difference in pressure to make much difference to the wear pattern. With crossplies, it takes a lot less.

John

Originally Posted by Tusker

What's the tyre construction?

The size looks like a crossply, which run at lower pressures than radials. If the pressure's too high, the tread area crowns - blows up like a balloon - & wears in the centre.

A radial of course has reinforcing under the tread to keep it relatively flat.

But the pic looks more like a radial tread pattern, so I'm not sure what's going on.

Regards
Max P

They're cross ply. .W.

Are we taling about the profile or the Rolling Radius?
- Worn tyres will have a lower Rolling radius, but hopefully will stay close to the original profile...

The profile is the relative proportions of sidewall height and width, such as a '50' is wider and shorter than a '70' . Also called Aspect Ratio. Bigger numbers = taller tyres, greater rolling radius and higher gearing when extreme... lower numbers = lower sidewalls...

But then there is the differant brand and their shapes... A classical illustration was the old Michelin X, and the Australian built tyres such as Uniroyal. (remember them ? Made in South Australia, also re-badged as Esso, both with a 40,000 km warranty)

- Michelins looked skinny and rounded alongside the 'wider' and flatter-treaded Uni's . - But both could be the same stamped size. Ride and handling were poles apart.

Wear may alter the apparant shape so that a brand new identical will not appear to be the same... depending on how abused -or not - the old one is...

Bottom line is, not good to mix your old one with a new on a car's axle.
Trailers are a differant matter.

Does that muddy the waters for you ?