78 GS1000 Track Day Questions

[mills]

1st thing: I'm in this for fun, not to win any races!
What tire size works well with this bike. I was thinking about going with a 110/90V19 in front and a 130/90V17 in rear. Is a 100/90V19 too small for the front? Is a 120/90V17 too small for the rear?
I would like to change my rear wheel to an 18", but that is further down the road, does that make a big difference in handling or is it just a tire availability thing?

[jabberjoe87]

I've seen some of the kz1000's at my track and two of the guys have stretched swing arms and have no bigger than 120's or 130's. I have a 750 that i drag race, just for fun as well and it has a 130 on it. I don't think its necessary to have a bigger tire until your running like 10's or something

[mills]

Maybe I should have said "road course" track day? Hallett Oklahoma.

[Steve]

Did the 1000 come with a 90 or 100 stock on the front? I would probably stick with the 100, either way.

Did the 1000 come with a 120 or 130 stock on the rear? I would probably stick with the 130, either way.

Unlike a car, you don't get more rubber on the road by putting a larger tire on a bike. Most times you actually get less. That happens because the larger tire gets pinched tighter than it should to go on the narrower rim. This distorts the profile of the tire, leaving you with less rubber on the road. A wider tire will also affect your feel in cornering. Some have tried a 110 in front and gone back to a 100 because it steered rather heavy. A larger rear will do the same, but maybe not to the same extent.

Overall, you will be best to stick to the stock size or, at most, one size over.

.

[tkent02]

Try one of each size, go with what works the best. Kind of like what that little Japanese engineer did thirty years ago.

[mills]

The best I can figure out, a owners manual somewhere said stay with 3.50V19 in front and 4.50V17 in back. This is a new bike to me. The tires on the bike now are not safe to ride on. I'd just like to hear from somebody that might have raced one of these things. I'm shooting for next March or April for her maiden track appearance.

[Rudeman]

1st thing: I'm in this for fun, not to win any races!
What tire size works well with this bike. I was thinking about going with a 110/90V19 in front and a 130/90V17 in rear. Is a 100/90V19 too small for the front? Is a 120/90V17 too small for the rear?
I would like to change my rear wheel to an 18", but that is further down the road, does that make a big difference in handling or is it just a tire availability thing?

I'd go with a 100 front and a 120 rear. Using stock wheels, you won't gain any footprint going from a 120 to a 130 but you will steer a little slower. The advantage of using an 18 inch wheel over a 17 is that you won't have to use a taller tire to maintain ground clearance. Taller tires will flex a little more and could lead to stability issues at racing speeds.

The stock widths in millimeters is 88.9 for the front and 114.3 for the rear. So if you go with my suggestion you'd still be running a wider than stock tire.

[Nessism]

The 18" rim width is only 2.15", vs. 2.50" wide for the 17". Not sure what is best.

[sharpy]

I used to race this and it had 18"s front and back. 150/80 (4.25 x18 rim) and 110/80 (250x18 rim). that would be your best 18 sizes. Getting a set on spokes wheels and using the rear stock rim on the front and buying a new rear is the cheaper way to do that..........



Or i can ask my mate you runs this what sizes they use. (17's)



Either way the first thing you shound get is a 1100 alloy swing arm and get it braced like the one above and this one......

[salty_monk]

I run 100 front & 130 rear. Avon Roadriders. Works great.

Dan

[mills]

"Either way the first thing you should get is a 1100 alloy swing arm and get it braced like the one above and this one......"... I've got to make a trip to the salvage yard in a week or so and a 1100 swing arm is on the list. I wish I could afford spoked wheels, but not right now. I'm going to get the front brakes working better and mess with the front forks a little bit too.

[Rudeman]

"Either way the first thing you should get is a 1100 alloy swing arm and get it braced like the one above and this one......"... I've got to make a trip to the salvage yard in a week or so and a 1100 swing arm is on the list. I wish I could afford spoked wheels, but not right now. I'm going to get the front brakes working better and mess with the front forks a little bit too.

Sent you an IM...