Petition to get Triumph to make standard rim size. 18 inch?

Or if your rich like Mex, you could have a second rear wheel and change out per riding conditions.
 
I just carry a plug kit, plug the car tire and go home running a 404 Dunlop on front pretty common most any bike shop has them about 95 bucks
 
Or buy a cheap $100 car tyre so you can finish your 5000 mile trip and get you home.

Thats what I did 150 miles from home had a blow out on the Avon. Slapped a car tire on it to get home ordered another one and **** canned the car tire when I was done. 80.00 .
Then bought compressor and a plug kit.

Most likely if your near a suzuki dealer they will have a bridgestone.
even if you have a 18 inch 240 you won't find a lot in stock so your still ordering.

True I get more variety with my 18 inch rim but the mileage is no better in fact its worse then the Bridgestone Exedra Max.
 

I agree with Warp; you're not going to find much in a 240 no matter what the rim size is in out of the way places. Plug kit ($20) and a few compressed air bombs to reinflate (like soda bombs) is my insurance. Car tyre to get you home or to somewhere that has what you want also a better option that spending $,000s. Issue we're talking about is choice, not emergency support.