Quote:
| Originally Posted by mjbayley Taken directly from Pirelli Web Site today 13th March 2009 for Ducati 600 SS
DIABLO
Front
120/60 ZR 17 M/C (55W) TL DIABLO Front - 2.2 BAR
DIABLO
Rear
160/60 ZR 17 M/C (69W) TL DIABLO - 2.5 BAR
Now as I have worked in automotive engineering for over 25 years.
I know that:
H rating on tyres is for max speed (sustained) of 125mph
ZR rating on tyres is for max speed of (sustained) of 181mph
I also know from calculation and where the rev limiter cut in that at Assen, Senetterton, and Donington, AntonyE was puling over 132 mph !
So I ask, why do DD go with H rating not ZR as stated and recommended on the Pirelli web site????
I know it's (prolly) the 'sustained' thing, but I think I know what I would rather be using (the old '1.5' times safety factor), and where does the club stand 'IF' there was ever litigation due to tyre failure ?????????????????
Mark |
mark
This ie easily answered, as these points were put to Pirelli back in 2004.
It is primarily to do with the weight and power of the bikes, rather than top speed. The weight and performance of a 500 will not put as much heat into a ZR rated tyre in that important 1st couple of laps as they will into an HR.
The ZR is for 100bhp and and say 190KGs and that weight and power would warm them up.
Chris