not so important topic

[chiz]

Hey I seems at my end it is impossible to get an answer for a simple question  , bicycles keep coming up. No mater how I word the question I am not getting the answer for when did tubeless tires get adopted by the motorcycle industry ... anyone here know the answer?  Chiz

[Pat Conlon]

Yep, that's a hard answer to find....I approached the question from a different angle, asking, when did the first cast motorcycle rims come out?
I found this:
The Yamaha RD400C sold in 1976 was the first motorcycle by a major manufacturer to be fitted with cast wheels, however, Honda began offering their Comstar composite wheels in 1977, marking the first time a manufacturer had included tubeless tires on a production motorcycle.

Source: https://en.wikipedia.org/wiki/Motorcycle_wheel

[chiz]

OK THANKS  I have a couple of cast wheels on two bikes yet they carry tubes because there is a second hole in the rim for a tire rim lock.

[Pat Conlon]

We have 2 holes, opposite sides, in our Miata track rims, for 2 tire stems. That way we can purge the air out while we fill the tire with nitrogen. (nitrogen helps keep our hot tire pressures consistent)