Topic: tyre size for CB750

[Scott]

Hello
I just picked up a CB750 1972 yesterday and the tires on it are old and cracked
The rear is 4.00 x 18   and  the front is 3.50 x 19
I want to order some tires over the internet but do not know what these sizes translate to
Thanks heaps for any advice
Scott
more questions to come

[MCRider]

4:00-18 = 110-18. 120 will work,
3.50-19 = 90-19

[andy750]

4:00-18 = 110-18. 120 will work,
3.50-19 = 90-19

As Ron said but Id use a 100-90-19 up front. For the rear I use a 110-18 on the back. The 120 on stock rims will cup prematurely and your handling will suffer on corners. I also a 1972 CB750.

[Gordon]

Keep in mind that inch sized tires (IME at least) have a taller sidewall than their equivalent metric sizes.  On my K1 this is a benefit for me because they fill out the fenders more for a better stock look, and it's noticeably easier to get it on the center stand. 

[MCRider]

4:00-18 = 110-18. 120 will work,
3.50-19 = 90-19

As Ron said but Id use a 100-90-19 up front. For the rear I use a 110-18 on the back. The 120 on stock rims will cup prematurely and your handling will suffer on corners. I also a 1972 CB750.

Yeah, there is rounding in all this as inches don't divide into mm evenly.
110mm=4.33in So that's an oversize/
100mm=3.94in.  So that's even more of an oversize, as stock was 3.25-19.

Still I agee with Andy, I shoehorned a 110 on my front, would outlast 3 rear tires and put down rubber for the dual discs. Still, overkill probably. 100 would be better.

http://www.industrial-enclosures.com/html/conversion-mm-inch.html

Per Gordon, the inch sizes were probably equivalent to a slash/100 sidewall.

[ekpent]

Honda factory recommended front tire for the 750 technically is stated as a 3.25-19.

[BobbyR]

4:00-18 = 110-18. 120 will work,
3.50-19 = 90-19

As Ron said but Id use a 100-90-19 up front. For the rear I use a 110-18 on the back. The 120 on stock rims will cup prematurely and your handling will suffer on corners. I also a 1972 CB750.

+1   My experience also.

[DYSKORD]

I went from a 120/90 in the rear to a 120/80. I also run a 100 in the front. The handling improved as well did thed appearance IMO.
Avon Road Riders were what I went with and have absolutely no complaints.