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Builtdesign
02-12-2011, 10:05 AM
From what I've read the best commuting oversized tire combo is the Pirelli Diablo 110/70 (front) & Pirelli ST66 140/70 (rear).

Okay, sounds great because I log almost 2K miles a month. But here's the problem, the Diablo is only P rated (93mph). And I'm not a speed demon, but in Phoenix most cars on the highway are cruising between 70-80 and m/c's 80-90.

I know that the speed ratings are rated for constant speed. So here's my question, is okay to exceed the speed rating at all? For example passing or just for a short period of time? Because its the front tire I am more concerned about this.

Perhaps there is another (oversized) front tire someone could suggest? I'd stick with the stock rubber but I just need more tire for the corners. The idea is to have a sticky front for braking, and harder compound on the rear for better mileage.

Puzzled
02-12-2011, 10:26 AM
That is a lengthy question to answer. The speed rating is not as simple as an expressed number. It is more of a combination of the load on the tire combined with the length of time "at" speed. A simple answer to your question is you will not have a problem.

I know this from when I installed a 250 on my Busa 7-8 years ago. I had several conversations with the techs from the tire company. They could not legally tell me what I was asking so they provided me with the information to which I was able to answer my question.

Puzzled
02-12-2011, 10:28 AM
Found my info from years ago.


A V rated tyre is rated to 149mph sustained speed. However, after 130mph, the load the tyre can take reduces by 5% for every 10kmh increase in speed up to 149mph.

Max Speed Max Load (%)
190kmh (118mph) 100
200 (124mph) 100
210 (130mph) 100
220 (137mph) 95
230 (143mph) 90
240 (149mph) 85

Therefore, as the speed increases above 130mph, the load reduces. These tyres are drum tested (ECE reg 75 conditions which are more severe than DOT high speed conditions) for ten minutes at each speed but with a different percentage load due to take account of the fact the tyre is running on a curved drum rather than on a flat road.

I hope this helps,
Best regards,

Peter J McNally

M/C Technical Product Manager

01225 357753

Puzzled
02-12-2011, 10:30 AM
This was for a 250 Avon.


Percentage...load rating.....KMH....MPH
of max load...in pounds...
100%...........1019.............190.....118
100%...........1019.............200.....124
100%...........1019.............210.....130
95%.............968..............220.....137
90%.............917..............230.....143
85%.............866..............240.....149
80%.............815..............250.....155
75%.............764..............260.....161
70%.............713..............270.....168
65%.............662..............280.....174
60%.............611..............290.....180
55%.............560..............300.....186
50%.............510..............310.....192
45%.............458..............320.....199
40%.............407..............330.....205

I came up with this based on the supplied answer. This tells me that at 45% of the max load rating the tire is good for 199mph at a sustained speed of ten minutes.

The max load rating of the tire is 1019 pounds at 42 psi. Tires are tested three pounds under the max pressure. 45% of the max load would be 458 pounds. I weighed the bike with me on it. The weight at the rear wheel was 280 +/- pounds with me sitting on the bike upright so I could see the scale. I would think that the weight load would lighten as I lean forward and as the bike increased in speed.

With the small amount of information I was given I believe that the tire is more than capable of anything I'll ever do with it.

Builtdesign
02-12-2011, 11:42 AM
Thanks Puzzled! That info makes much more sense than the other stuff I found on the web.