Tire Size Difference

How far from stock can you get in tire size? I have an 84 ZX750 GPZ and most of the tires I see out there are not available in the size for this bike. Maybe I am looking in the wrong places.

The main concern would be the clearance at the swingarm,going with a wider tire.
Make sure that you can at least,fit a finger in between the tire and the swingarm.
Don't know the stock size tire for that bike,off hand.

What tire size is on there now?

The tire size that is on there is stock.
Front: 110/90-18
Rear: 130/80-18

Most fronts don't seem to get large enough, and for rears the closest I can find in high quality tires is 130/90 or 120/80

Take a look at the Bridgestone BT45's, that's what a lot of GPz750 owners use.

I see a ton of 110/90-18 tires because I run one on the back of mine. If push comes to shove, you could buy a so-called "rear" tire and flip it around and put it on the front.

Some tires come with the sidewalls marked for both front and rear fitment (opposit direction), so I'm a little skeptical when they say that you can't take a rear tire and run it on the front.

I thought if you ran a rear in a front it wouldn't behave. Poor handling and something about belts seperating?

bountyhunter wrote:

If push comes to shove, you could buy a so-called "rear" tire and flip it around and put it on the front.

I would NEVER put a rear tire on the front or vice-versa unless the tire specifically says "For Front or Rear Use" on the tire.

Later, Doug

Dennis Kirk lists 10 rears in that size, and 20 choices for the front. You can get anything from Chen Shin to Metzler in those exact factory size. Get your tires there.

PFC FNG wrote:

I thought if you ran a rear in a front it wouldn't behave. Poor handling and something about belts seperating?

As I said, I tend to be skeptical. The rear tire has the stresses of acceleration and braking working on the tread blocks (torquing them in both directions). It also has a lot more load on it (hence the rear tire's short life). If the rear tire can handle all that, I don't understand how it could possibly NOT be able to handle the front tire service which only has free running rotation and braking (torquing the tread blocks in only one direction).

I am skeptical because I can not theorize any case where a tire which could handle being torqued in both directions would fail prematurely if stressed LESS by being put on the front. Maybe there's a reason, but I don't see it.

I could imagine a tire specifically designed for the FRONT to handle only torquing the tread in one direction might not like being put on the rear where it gets yanked both directions, but I think if the tire is built to handle rear service it should work on the front no sweat.

I could be wrong, but the fact that I have seen many bike tires with both front and rear fitment arrows on the sidewall of the same tire tends to reinforce my skepticism.

If there is a scientific explanation as to why a rear tire would fall apart running on the front, I would be interested in knowing how that's possible.