mattcfish wrote:So...what exactly is the difference in rim design between a tubeless Lester and a tube Lester? Assuming you resolve the valve leakage issue, what is the risk of going tubeless on a tube specified Lester or snow flake?
Rims designed for tubeless tires have a "safety bead" which makes it much more difficult to break the bead seal on the tire. This is why, when changing tubeless tires on a rim designed for such tires, "breaking the bead" is so much more difficult than when changing tires on tube-type rims. The "danger" of running a tubeless tire on a tube-type rim is the sudden (as in: instant) deflation that can occur when hitting a curb edge, pothole, etc.. That such a thing can happen is certain, but how likely such an occurrence is, is completely unknown. It certainly is rare. It seems likely that low tire pressures would make such an occurrence much more likely than it would be on a correctly inflated tire.
Those who go the tubeless route on such rims believe that the the improved safety of a tubeless tire when encountering a puncture, the ease of roadside plugging of tubeless tires in the case of such a puncture, and the reduced unsprung weight and heat development of the tubeless tire outweigh the unlikely possibility of a sudden deflation from an unseated bead. Those who object to use of a tubeless tire on such a rim believe that, regardless of how rare such a sudden deflation occurrence might be, the catastrophic nature of such a thing happening totally outweighs any possible benefit.
In reality, neither side has any real numbers to back up their decision, and, without such numbers, you can make a reasonable case for either side.
Pick your poison.