I own both, and having "field tested" an ASP, I can assure you that is not the case. A baton is heavier, much more sturdy, and has its weight nicely distributed for beating purposes. Batons are purpose built for fighting, whereas bike pumps are purpose built tubes for pumping air, yes even the heavier steel ones from the 70's. Using a bike pump as a club is about as clever as pounding 16 penny nails with your wife's favorite flower vase.

On the other hand, I will admit that I have carried a frame pump filled with loose bird shot, and that would have certainly been an effective weapon. In places like Kalifornia or DC, its an attractive option.