I have ridden one of them before. Many years ago though. They were also very popular with some of the ultra-marathon/RAAM riders in the early 90's. The beam is actually two halves with an elastomer sandwiched between them which adds durability to the suspension action of the beam. Pretty good idea, just not eloquently executed, and it was indeed very hard to get these bikes anywhere close to being lightweight. The one I rode was even a "pro" model and was loaned to be by John Stenner (R.I.P) for a weekend. Honestly, on a long flat-ish ride, it was very comfortable. It was a bit weird though having a super smooth ride in the saddle and a rather harsh ride in the handlebars. The front end of the bike was built like a tank and had a very hard riding aluminum fork.