>> Jeg er bange for at designerne alene har en ubehagelig stor del af
>> ansvaret for mønstrenes udseende
>>
> de færreste der bruger mønsteret til andet end udseende på et
> sportsdæk, så det har du helt sikkert ret i. "MC vandskrækkerne" ..
Har I noget at bakke de udtalelser op med, eller er det ren gætværk?
Har I læst det Avon-interview jeg linkede til? .. se udvalgte passager
herunder(*). Et dårligt mønster giver hæl-tå-slid/"cupping".
> Spørgsmålet er så hvilke dæk der er bedst til brug i hele sæsonen (5-30
> grader, regn og sol) sportstouring dæk?
- Et med masser er silica i:
"One of the biggest recent advances has been the inclusion of silica,
which has happened over the last couple of years. Silica effectively
improves wet grip.
It’s all about temperature. A hard compound might [not] really work
between 10 degrees and 90 degrees, say, and if it’s raining it might never
get to that 10 degrees. Silica brings the effective operating temperature
down to zero or one degree, so it will work in the wet. Silica also
extends the tyre’s performance at the top end of the range by reducing the
effects of overheating."
*)
"Are sports tyre tread patterns more about fashion than physics?
No, the tread pattern is really important. If you wanted a tread pattern
just to clear water, you’d have a racing wet. But a road tyre doesn’t just
have to clear water on wet roads, it has to run on dry roads without
irregular wear and tearing on the edges. If you put the grooves in the
wrong place you’ll get high spots and low spots.
We came up with the ideal groove pattern by taking a slick and cutting
fan-shaped grooves into it to establish exactly where the wear was taking
place, then we set up our road-tyre grooves at ninety degrees to those
maximum-wear grooves.
But isn’t there one ideal pattern that everyone should follow?
From a physics point of view the grooves do have to follow a certain
design. At one point it did seem that everyone else had missed the point
on tread patterns. Without mentioning any names, you’d get horrendous
stepped wear on some of their tyres, the fronts in particular. You had to
throw them away long before they were worn out, simply because the pattern
was all wrong. Avon pioneered inverted front grooves on front tyres,
recognising the fact that the rear tyre is about traction and the front is
about braking. For years people told us we were putting our tyres on the
wrong way round."
--
Simon, Århus
Kawa ER-6n '07