RW4 owners with tire troubles, make yourself heard. This is a serious safety issue even if you have the skills and $ to resolve it yourself.
http://bitly.ws/s67i
The only real issue I've noticed is that the 22" tires and tubes are only offered by one company and Rad is the only retailer who offers them. Thus far they are often not available, probably due to the current supply chain issues. I hope they get it resolved soon.
Other than the unique size of the RW4 tires and one post on this forum about tubes/tires blowing out or going flat I haven't seen anything about tire safety issues for the RW4. What "safety issue" are you talking about?