Not wish to extend the debate too much but I thought it would be useful to compare the tubeless rim from Robs link with a picture of a Snowflake rim I took last summer. Remember Summer and flowers ? I always work in the garden rather than the garage when the suns out. The lack of any significant hump and different slope to the rim are obvious. What I want to know is if the snowflake rim is so unsafe without a tube how come it can be so damn hard to seat the bead and too break it again when changing tires ? 
Barry,
Thanks for the illustrations of the conventional Tubeless Rims vs. LS (?) Rims.
SW Moto Tire mounted Bob_Roller's Lasertecs without tubes. Bob, what are you trying to say with your last post?
Wow, talk about confusing.
I wonder just how different these tires would react to a "sudden deflation" with or without tubes?
Also, why would the "tubed" tire be any less suseptable to coming off the rim in the event of a punture severe enough to result in a "blowout"?
