MOPED ARMY

Often, older motorcycle tires have a Standard Inch System. These tires do not have an aspect ratio designation marking. The cross-section tire height is 100% of the width. An inch-sized tire is bias-ply construction and is not belted. However, these are being phased out and are not used on newer motorcycles.

That's from Denniskirk.com.

Dennis Kirk does list the inch/mm crossover more correctly.

https://www.tacomaworld.com/tirecalc

Meant for truck tires, but input some Moto sizes and give you an imperial measurement set

There is no real direct conversion because the sizes do not always match up to an existing size, so you basically have to go with what would fit/not fit with a close size so you do not have interference from forx, frame, trailing arm, shocks, fenders or chain(s). This is my "closeness" chart with sizes that actually exist (though some sizes are hard to find) and you need some goodly wise rims for the 80 ratio.

2.25=70/90 or 80/80

2.50=80/90 or 80/80

2.75=80/90 or 90/80

3.00=90/90 or 100/80

3.25=90/90 or 100/80

3.50=100/90 or 110/80

4.00=110/90 or 120/80

Ive been running Michelin m29s 2.75-17 on two of my puchs for years. Ive loved them. But they're no longer available. Id like to stay as close to this profile as possible and there are a number of brands that offer options in mm sizes. Thats why I'm trying to get to the bottom of this. Guess I'll just order Michelin Pilot Streets in 2.75-17 and hope I love them as much as the m29s.

Jesse do you like the pilot streets? (edited)