I noticed you put the Thudbuster on the Curve. I think all Dahon's should come with this suspension seat post because these bikes are hard to ride. Especially the 16' inch folders and this is the reason the Brompton has a built in frame suspension. However, most people on the forum always say the Brompton is more comfortable than the Dahon but they never rode one that had a Thudbuster. I happen to think the Thudbuster is a better suspension system than most folders with buit in frame elastors.