Tyre spped ratings, different construction?

mattyfez · 5 Dec 2010 at 12:18

Hi all, Im almost ready to push the button on some Unroyal rainsport2's, and while I have a pretty decent understanding of tyres, I have always been curious about speed ratings, and load ratings to an extent...

Now apart from the obvious, how is this actually measured, is there a difference in construction, or what? does anyone know what dictates the difference between say an "V" and "W" rated tyre, assuming they are the exact same model tyre?

ghop · 5 Dec 2010 at 14:33

I was wondering this myself. I'm thinking the faster speed ratings one use a better compound?

mattyfez · 5 Dec 2010 at 15:07

I've done a bit googling and not really turned up much, I would assume though it would be a different compound or slightly more robust construction in some way.

The thing I don't get though, is if the compound is altered, it would mean that a tyre of the same type could have quite different handling characteristics at different speed ratings.

Dogbreath · 5 Dec 2010 at 15:08

The difference is in the construction of the tyre; the tyre has to resist the formation of a standing wave in the carcass (effectively resonance) at high speeds which can lead to destructive levels of heat build up.

mattyfez · 5 Dec 2010 at 16:06

Ahh, ok, that would make sense, so the tyre has a slighly more 'robust structure' for want of a better phrase - is there any data available anywhere that details exactly what makes a 'W' more robust than a 'V'?

burns · 5 Dec 2010 at 18:54

Some interesting pictures of the standing wave on e-tyres here

Hawk Tuah · 5 Dec 2010 at 23:07

I would have thought the main differences would be in the sidewall.