tire differance

[dvibbert]

Is there much difference between a 150/70/17 compared to a 140/70/17?

[md86]

10 . The difference is 10 .
Use the 150 if you can .

[The CyberPoet]

Most 140/70-17's will be bias based tires.
Most 150/70-17's will be 150/70ZR17's and thus be radials. Always pick radials if you have the choice on a sports bike, as it has distinct safety advantages if the tire gets cut/punctured while you are leaned over in a turn.

For a '91 Kat, I recommend moving to a 120/70ZR17 front and 150/70ZR17 rear, both of which are the maximum safe sizes that you can fit on the OEM wheels. These sizes will also give you the advantages of the latest tire tread technologies on the market, which translates into both more grip AND longer tire life.

Meanwhile, to understand the numbering system (and a lot of other issues), see this thread, which used to be a sticky (and $#@% if I understand why it isn't any more):

http://www.katriders.com/forums/viewtopic.php?t=5551

Cheers,
=-= The CyberPoet