paul b thanks for this thread brilliant.
i to want to go the custom route like you i like my thorn sherpa but don't love it so to speak.
i find it's more a donkey than a race horse especially when it comes to climbing..don,t get me wrong the sherpa is a great bike but the touring i do i would much prefair a much lighter faster bike .
on longer rides i get back pain on my sherpa, believe me i adjusted the bike every which way to try and feel more comfy maybe i need a slightly longer top tube.you say that worked for you.
anyway thanks for now .