I looked at their website just now because you caught my interest with this. It's a suspension system, basically. That makes it a bit strange on a rigid bike. There's no way to adjust spring rate or preload or damping, it's all built in and the same for everyone at a given frame size. Presumably they are clever enough to have made it stiffer at larger sizes. But anyhow, I'd guess that ten pounds more would not make a huge difference.