I have never been a fan of Simplex gears, The 4speed, orig equip that I have on my 52 Claud is a pain in the arse. I did have a double cable tension one at one time a real mess, went into the wheel at one time, SO Whats so SPECIAL about the 543? One on Ebay with a start bid of $695.00! I have NEVER had any problems with Campag from the Gran Sport on BUT I never seen them for any where $695.00 Is this a case like the Hetchins frames, Price put way over, in my mind the TRUE VALUE by collectors? Cheers John Crump OldCamapgfanBrit, Parker, Co USA