If I was to cut the top tube out of a carbon frame and attempt to beat someone to death with it, would it's low mass restrict it's effective bludgeoning ability?

depends

would you intend to accelerate it or bludgeon at a constant speed ?

No, but it would shatter into a million pieces, enter your blood stream and kill you when it reached your brain…..

The impact effectiveness of an object is a function of its momentum. So what it really boils down to is if you could swing your arm proportionally fast enough to account for its low mass. You may be biomechanically limited. THe same goes for a lead pipe, it's high mass may be a detriment to your ability to swing it if you're a little weed.

Hope that helps.

Si C

The "someone", is it someone that believes that he can hit a golf ball further with expensive carbon fibre shaft golf clubs?