Eric Gorr makes no mention about an issue with no bottom end. He does recommend the v force because its more reliable to the chip prone stock reeds. There you go. But he also adds that the bike has a real short power band, it needs a lot of machining to give it a broader power band, mid to top, but he can do it. If you plan on hopping it up, get the v force, if not get the boyseen. I always took the boyseen as bottom~mid, and the v force more mid~top. Vintage Bob