Kawasaki Sportsbike Riders Club - Australia - Online Forum

by **bishboy** » Tue Mar 23, 2010 2:46 pm

I've just bought some new (secondhand) slicks and the profiles are different to what is currently on the bike.

Currently: 190/55

New:
Battlax 190/645
Ntec 190/65

Given that the higher profile on the new tyres would raise overall ride height, should I reduce the ride height (via ride height adjuster on the shock) to maintain the same ride height and if so by what amount. If I reduce the ride height by the difference in profile, that would be 18 or 19mm which seems excessive

Or should I just ride and see how it goes and then reduce ride height by say 10mm and see if any change?

Also, is it correct that pressure in a Ntec rear should be 21psi hot and front 33psi hot?

by **Wattie** » Tue Mar 23, 2010 2:48 pm

ride it and see.

yeah 21-24 hot will be ok.

33 hot front ok too.

you will like them...

by **MadKaw** » Tue Mar 23, 2010 3:00 pm

The number on the bridgie is not profile as per the others the 645 is the overal tyre diameter.... 650 is the new bridgie...

and no to your other question - the ntech (which I believe should be a 195 65 - not 190) is actually only about 10mm taller than the bridgestone in overall diameter, meaning a 5mm increase in ride height.. and probly worth leaving..

by **oldman** » Sat Mar 27, 2010 5:27 am

The larger diameter will throw your speedo off a little, (you will be going faster than the speedo indicates) plus your overall gearing will be slightly higher as well. probably not enough to worry about. This formula will tell the tale: RPMxFSTxtire circumfrence in mm, (divided by) PGRxgear ratioxRSTx26,817 = speed in MPH . RPM= revolutions per minute of the motor. FST=front sprocket teeth. tire circumference in mm is obvious. PGR= primary gear ratio. gear ratio=the gear ratio of the gear you are in, 1st, 2nd, etc. RST= rear sprocket teeth. and 26,817 is just a number used to convert all this shit to MPH. The tire circumference of a 190/50 ZR17 is 1975 mm. If this farking formula doesn't drive you to drink a Jim Beam you must be on drugs. I just did it for sixth gear on my bike and it kind of gave me the idea of the speedo error, (I dropped a tooth on the front sprocket).