WOW!! Thanks for that info! Ironically I had recently posted about weather checking and cracking on my BW's. They never spent a night out outside and still getting pretty bad weather checks. Looks like I need to order some also.
What's confusing is every tire I've had for 60+ yrs except BW has never cracked the sidewalls. The tread can get roughed up from rocks and whatever. At one time I had a floatplane parking deck made from old tires. When I removed the deck after 35 years none had weathered to the point of my first BW after 5. Not bashing just an observation.
The adapters ^^^^ are valuable. Proof that real rubber lasts. I had several and couldn't give them away at one point until owners of vintage planes rediscovered them. 8:50x6" tubes fit.