This is a great thread!
I thought it might be good for me to chime in and answer a few questions.
First, I should mention that the pictures are from an OB line cue shaft. The Classic line is a little different.
About the silicone rubber core. First, it's only on the OB line, and we call it our "Noise Dampening Core". It's a big part of what gives the OB's the quieter hit. The material is actually a silicone foam rubber, and it's intended to weigh about the same as the maple it replaces. The core extends from just above the joint to about 5 or 6 inches below the tip. To make room for it, we have to drill the cue shaft all the way from one end out the other. Drilling is the tricky part. It doesn't make the shaft "boingey", but it does quiet the hit. Those who like a softer quiet hit love it. We haven't talked about it much, but don't really consider it a trade secret or anything. Based on this thread, I think we'll put some pictures together and get it up on the website.
For those who want that "ping" or sound when they hit the ball, we have the Classic line. The Classic line is more stiff, and has that firm crisp hit that some players are looking for.
We use the same "tip end treatment" on all our cue shafts. Originally, it was a balsa core but we switched to a more consistent foam material. The balsa supply started to vary greatly in density and we spent too much time sorting and culling. The "mass reduction foam" is extremely consistent and helps us keep our prices down and still build them here in Plano Texas. The mass reduction fills that area between the tip and the noise dampening core.
Our goal is to offer extremely low cue ball deflection in shafts to suit all the different tastes out there. We have the softer quieter hit of the OB line as well as the more firm and crisp hit of the Classic line. And, of course, we offer two different tapers within each line. A more traditional 12.75mm with a modified pro taper, and a 11.75mm with a modified conical taper.
So the OB Classic and OB Classic Pro are all glued wood behind the tip end foam?