1972 Honda CB750 tire sizes

 

I have an old 1972 Honda CB750 with bad tires I would like to replace.
I am trying to find a a place I can go to and get the correct tire
sizes or a conversion chart. The front tire says 3.5 x 19. The back
tire says 130/90/18. I don't know if only one tire size will fit or if
I have a range, at any rate the front tire seems to be the old size
scheme so I need to convert to newer tire size. Any help would be
greatly appreciated.

 

readme wrote:

I haven't matched those sizes, but I've found with other sizes that I
could usually get a metric equivalent that was no more than 1/4" too
wide.  That way you might get high quality tires for a reasonable price.
  As long as the outside diameter is that close or closer I don't think
you'll notice much difference (actually, a new tire that's slightly too
wide will probably be much better than a worn tire and if the old tire
has gone square, much much better).  You might try the cb750 group on
yahoo groups, there are a lot of people there, also there are a couple
of other groups that have a lot of cb750 owners, try googling for cb750
groups.  Good luck.

 


A 3.25/3.50 x 19 is the right size for the front tire, but a 130/90 x
18 is about 5.0 to 5.1 inches wide and that's a bit wide for your
stock rim.

The 130mm tire will probably "crown" on the stock rim. The rear end of
the motorcycle will fell like it's falling out from under you when you
lean over if you mount wide tires on narrow rims.

A lot of riders used to install 4.25/85 x 18's on the back of their
CB750's.

A 4.50 x 18 would be OK too.

http://www.usmotorcycletires.com/tire_size_conversion_chart.php

This particular chart compares metric width to inch width and has the
alphanumeric codes too.

But it doesn't show the optimum *rim width* for each tire size.

You don't want to buy tires that are a lot wider than stock and mount
them on your stock rims because you won't be able to use the sides of
the sides when  you lean over.

If you go to www.mawonline.com and click on "tires", you'll find a
listing of all the tire manufacturers and when you go to the page for
any particular manufacturer, you'll find a link to the company's
website.

When you get to the company website (it's not too obvious how to get
to Bridgestone's site) you will find recommendations for replacement
tires for
your motorcycle.

You'll be using bias ply tires, not radials, they won't fit your
narrow rims, so don't bother looking for radials.