Tire help

[bonstrosity]

So I went through and read all of the posts about tires yet I'm still a little confused. I think I need about a 120 on the front and a 150 on the back or maybe up to a 160 on the back. Does it matter what size the second number is? weather it's 60 or 70, I know the rim size is 17 so I'll make sure to stick with that. Can someone just list off some tire size and combinations that will work on my 92 kat 600? I'm planning to either go w/ the metzelers or the diablos.

[arsenic]

the first # i.e. 120 is the width of the tire in mm. the second number i.e. 50 deals with sidewall height. so in the case of 120/50 the sidewall is 50% of 120 mm. the last number is rim size i.e. 17. my favorite set up on the kat is 120/60/17 in the front and 150/70/17 in back. some tire sizes that will work are. front - 110/80 (stock), 120/60, possibly others. rear - 140/80(stock), 150/70, 160/60. I think that about covers it. I'd go with metzler Z6's in 120/60 and 150/70

[WildKat]

that about sums it up I think. Good Info !

[kwebbel]

Just one little comment, the rimwidth is allso important! a pre-98 rearrim is only 3,5" wide thus restricting the tyrewidth to a 150/70 (max)
Another point off interest, the original tyres are bias-ply, choose for a radial tyre, the construction is safer.

[bonstrosity]

Thanks for the help, thats just what I needed. I didn't know the second number was a percentage instead of a measurement. is there any advantage to having a bigger sidewall (ie second number) than a lower one?

[BISQ]

Thanks for the help, thats just what I needed. I didn't know the second number was a percentage instead of a measurement. is there any advantage to having a bigger sidewall (ie second number) than a lower one?

It affects the ride height of the bike (front, rear, or both), for one thing--essentially, it can change the handling and/or suspension dynamics.

[The CyberPoet]

Thanks for the help, thats just what I needed. I didn't know the second number was a percentage instead of a measurement. is there any advantage to having a bigger sidewall (ie second number) than a lower one?

Bisc covered it basically. In more detail:

The taller the sidewall, the more the tire can flex to take up minor surface bumps, thus reducing the amount of work the suspension has to do (and making the ride smoother as well as keeping better contact with poor surfaces). A shorter sidewall, on the other hand, flexes less, and thus makes for slightly more confident grip when leaned way (way) over, and thus is preferable for track and race useage (where surfaces are very smooth). The stock sizes for the 98+ kats is 120/70ZR17 & 150/70ZR17; for the pre-98 Kats, it varies between 140/80 and 150/70, depending on the year and market. 140/80's in the right weight category for a Kat are getting very hard to find, and I recommend 150/70 as the preferred size for both new and old.

Cheers
=-= The CyberPoet