What tire size??? inch to metric

[kal-el428]

Long story short, what size tires will fit on a 76 CB750F??
I currently have 3.25-19 on front and 4.00-18 on the rear.
I have found conversions from inch to metric which states that the above sizes in metric are 100/90-10 front and 110/90-18 rear.
While looking for new tires, I have found that there is a price difference between a 3.25-19 and a 100/90-19, and same for the rear.
So, if these are the same size, why the price difference???

 

[dirtdigger]

Are they the exact same tire? One may be a bias ply and the other my be a radial. One may be designed for tube use the other may be tubeless. A lot of differences in tire manufacture and materials cause different prices.

 

[kal-el428]

Digger, you can see the sizes and price difference for the front on the drop down menu on this page --> http://www.motosport.com/motorcycle/MICHELIN-PILOT-ACTIV-TIRE-COMBO

 

[kal-el428]

I am still unclear why the price difference between a 3.25-19 and a 100/90-19
Any idea???