Tires???

[katana94]

Hi guys,

I just bought a 94' Kat 600 and was wondering what's the maximum rear tire width and lowest profile I can put on it. It's got a fairly new set of tires on it (140/80 and 110/80) but I want to go lower profile i.e., 150-160/50-60 if possible because the bike is my GF and she is short. I've found a few 150/60 and 160/60 but havent' been able to locate any tires in those sizes with '50' sidewalls.

It Would be great if there's a way to lower it a couple of inches but so far I can't locate any lowering links for pre-98 Kat. I don't want to throw the current tires away because it has less than 1000 miles on it and I don't want to spend money on a set of lower profile tires if I can help it.

Any help with locating a pair of lowering links or showing me how to lower the bike a couple of inches without swapping tires would be greatly appreciated...and yes, I did the the search already but can't find lowering links for pre-98 Kats.

TIA,

New K-member

[The CyberPoet]

(A) 150/60ZR17 will fit, but you need to check weight requirements to make sure the 150/60 will match those required by the bike (most won't). Ditto 120/60 for the front.

(B) The common ways include shaving the seat, raising the forks in the triple trees and getting the existing suspension links rewelded to be taller (I haven't met/found anyone making the pre-98 suspension links in a shorter/taller version yet; shorter links = taller bike & visa versa).

(C) The reality may simply be that the bike is too big/tall for her (if her inseam measurement isn't at least 29.5" -- about the max you can drop it to, it will be, especially if it's her first bike). If that's the case, consider selling it and getting her something more appropriate to her inseam & size.

Good luck!
=-= The CyberPoet

[BarMatt80]

on dropping the bike, is it a 1:1 ratio, 2:1 or what. for every inch you want to drop the bike how much do you have to lengthen the dog bones?

[The CyberPoet]

I'm not sure on the pre-98's curved bones. On the 98+ models about 1/4 of an inch will give you roughly about 1" change in seat height.

Cheers,
=-= The CyberPoet

[katana94]

Thanks for the responses guys.

[katana94]

on dropping the bike, is it a 1:1 ratio, 2:1 or what. for every inch you want to drop the bike how much do you have to lengthen the dog bones?

I'm not sure I understand the question but does the dog bones have to be lengthen too when the bike is dropped?

[The CyberPoet]

Lengthening the dogbones (the rear suspension links that set the lower shock pivot height) is the normal way of lowering the rear of the bike.
The 98+ Kats use straight dogbones (I sell shorter OEM ones to raise the 98+ Kat about 1" at the rear; Noublie sells custom-machined steel ones that will make a 98+ any height desired -- taller or shorter by whatever you want). The curvature of the pre-98's dogbones means that you can't simply measure, add length to the dogbone and mill a new one -- you have to take the arc distance into account -- and no one has gone that extra step yet that I've seen. Shortening it wouldn't be too bad, but lengthening it would be a royal PIA.

Cheers,
=-= The CyberPoet

[katana94]

Thanks for the explanation...I'll do some more research and see if it's possible to lower the bike 2 inches w/o the links.

[The CyberPoet]

Thanks for the explanation...I'll do some more research and see if it's possible to lower the bike 2 inches w/o the links.

There is no safe way that I know of to lower the bike 2 inches at the seat without lengthening the links -- doing so would make the bike unstable.

Figure:
1/2" seat shaving
1/2" moving from 70 to 60 profile tires
The rest all has to come from dropping the front & rear -- and just dropping the front enough to get another inch at the seat without any changes at the rear would NOT be wise.

Cheers,
=-= The CyberPoet

[katana94]

Since the current tires are 80, I should be able to drop an inch by going to 60 using your calculation...good to know. If my girlfriend gets a pair of boots with another 1/2 inch thicker sole, it should come up to about 2 inches with that combination.

[The CyberPoet]

The formula for figuring out how much difference the sidewall drop will make is approximate. It goes like this:

First number: width across the tire tread area in millimeters.
Second number: sidewall height expressed as a percentage of the first number.

Thus a 150/70 is supposed to be 150 mm wide and (70% of 150) 105mm tall. Moving to a 150/60 would make the sidewall 90mm tall, and net you a 15mm difference height in theory (a hair over a half inch).

The problem is that 150/70ZR17 means that in reality the tire will fit where a 150/70ZR17 is called for, not specifically that it is actually exactly a 150/70ZR17 when brand new (and tires literally grow over the first several rides as the rubber heats/cools & rotates outwards under force).

As an example, a Metzeler Z6 in a 150/70ZR17 mounted on the rear 4.5" rim of a 98+ kat will normally measure out to be 159/61ZR17 after the heat-expansion numbers.

Cheers,
=-= The CyberPoet