pop quiz on tyre speed ratings

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internetscooter
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pop quiz on tyre speed ratings

Post by internetscooter » Tue May 22, 2007 9:36 pm

I am planning on running a 10 inch wheel Vespa in 2008. I hope to do somewhere between 160Km/hr and 180Km/hr in the 250cc class.

I thought I could get "H" rated (210Km/hr) Dunlop K627 tyres which would do the job nicely, however I have just found that the rating drops to "J" (100Km/hr) for the size I need :(

I do have Sava MC18 tyres which are rated "P" (150 Km/hr) with a load of 195Kg each.

My search for a solution has taught me a lot, for example, "H" rated is not a straight speed rating, at 160+ the speed is dependant on PSI and load. 30Km can be added by dropping the load by 15% (http://www.tirerack.com/tires-techpage-1/72.shtml)

So would it be correct that "P" rated tyres would also technically pass as long as I didn't take my wife and luggage along? i.e. Me + scooter are about 200Kg, so the tyres are only getting about 50% of the specified load (100Kg each). With half the load they should easily exceed a 180Km/hr rating (maybe even as much as 250Km/hr).

Cheers,

Paul

gazza414
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Post by gazza414 » Thu May 24, 2007 7:35 pm

Hawkwind is the guy to answer this mate
1 FAST HAYABUSA 217.443mph so far
9 Official Timeslips over 200mph
Very much the apprentice

internetscooter
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Post by internetscooter » Sat Jun 02, 2007 3:25 pm

thanks - I have been in contact with hawkwind.

The tyre manufacturers have kindly provided me with data of possible speed usuage with different load and tyre pressures. Basically the tyres I have are good for the job with the load that they will be given (though with wife and luggage on the back they won't).

Dr Goggles
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Stick to that story

Post by Dr Goggles » Sat Jun 02, 2007 7:10 pm

internetscooter wrote:Basically the tyres I have are good for the job with the load that they will be given (though with wife and luggage on the back they won't).


of all the cunning stories I've heard that's one of the most cunningest :wink: :wink:
...few understand what I'm trying to do , but they vastly outnumber those who understand why..

internetscooter
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Post by internetscooter » Sat Jun 02, 2007 8:25 pm

cunning...

I bought a set of scales today to measure the load front and back with me on a standard scooter (no bits removed). I can confirm that there is enough spare load for a few slabs of beer to be carried :D

grumm441
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Post by grumm441 » Wed Jun 20, 2007 6:45 pm

Paul

You should leave the slabs in the esky
They will not stay cold on the scooter

G

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