Tire question

Hello all,

This is my first thread so forgive me if I am asking a question that has been asked 100 times. I searched and was unable to find what I was looking for. I just bought a 1976 KZ900 and need to buy some new tires for it. I am keeping the stock rim and also swingarm. From your guys experience whats the widest/tallest rear tire I can go. If there is already a thread discussing this just point it out to me. Thanks for the help!

Ltd or Std?

Are you running mag or spoked wheels? I think you might be able to get by with a 130 but might rub on the chain guard on the rear and the front maybe a 100-110 depending on who made the tires. Are you runing a 19" front and a 18" rear?

Remember to buy bias ply tires as this bike is not set up for radials.

I'm not sure, going by the stuff on Z1 enterprises its an A4 if that makes sense and I have spoked rims. Right now the rear tire is 120/90 B18. and the front is 19 inch. I'm curious of the people who just do a restoration job what size they go with. I would like to get as big as I could on the back.

120/90-18 is as large that fits. Yes guys have run larger, but I'd about guarantee anything larger will rub the chainguard. Possibly you don't have the chainguard or are running an aftermarket chrome one. In this case you "might" be able to fit a 130/90-18 however you have a 2.5" wide wheel and a 130/90-18 is no good for that narrow wheel. Again, I'll say guys have done it, but it's not right in function or appearance. You could get a wider wheel laced on, then run wider tire, that's cool, but stock wheels-no. All my KZs have a 120/90 on the rear, and even that is too large for the wheel really. Factory was a 4.00-18 which is narrower than a 120/90 but approx the same circumference. Really this is the size to run.

Thanks that what I was looking for.

If I was to build a custom swing arm whats the absolute biggest tire I could put on the stock rim?

76 KZ900 wrote:

If I was to build a custom swing arm whats the absolute biggest tire I could put on the stock rim?

The widest tire on a stock rim would be a 130 regardless of how wide the swingarm is. The stock rim is only so wide so it can only take so wide of a tire. You can relace a wider rim on the stock hub and go much wider.

Later, Doug

76 KZ900 wrote:

If I was to build a custom swing arm whats the absolute biggest tire I could put on the stock rim?

FYI, going to a wider rear tire on the stock rim basically throws away tire life. Street tires in the back wear out burning away the center strip of the tire. As the tire gets wider (keeping the rim width the same), it pushes the center section of the tire out more and makes this worse. There actually is a reason the stock tire is 4.00-18, that's what matches the rim width and holds the tire in the correct profile to the road.

Good Deal! Well at least I know my options now. Thanks guys.

I bought a set of Dunlops a while back and I am very happy with them. www.dunlopmotorcycle.com/tirecatalog_tire.asp?id=8 [img size=150][/img]

The GT501 is a great tire. DO NOT BUY D404 DUNLOPS. Spend the extra $$ for the better tire.