Is it just me? Check out this seat on this Rocket, it's from the Carpenter Racing's web site ( I think). See the ridge on the seat? How can it be comfy?
Ah-ha! The penny has dropped. I didn't see the small bars... so you would be leaning forward and as Scop suggested, it would stop you sliding back the seat. I didn't know it was a drag bike... Got it, I'll get back in my box now. Lol.
T.