OB Break Shaft

i dont know about the jumping part, but my ob breaks great. I had them take the shaft down to 12.4mm and i love it.

IMO, OB cues made the shaft 13mm for a reason, there's a study behind the design so you can achieve the optimum break. If I we're you, I wouldn't turn down the shaft diameter, I also wouldn't jump with the shaft. I suggest that you take a look at the BTX shaft by Mike Gulyassy, the shaft is ideal for both breaking and jumping.

I was gonna ask about the ob break how does it compare too the alex brick?