This is a long question. Recently I won a TT frame on eBay which has a 700c rear and 650c front. Firstly, the rear seatstays are so narrow that it can't take a 23mm tyre...no problems there I think because a 20mm will certainly fit and possibly a 22mm. Secondly I already have Zondas and Carbones, so swapping out the 650c fork for a 700c would save having another wheel clogging up the place. I'm no mathemetician, so I am unable to calculate roughly how much of a seat angle is lost by raising the front up by an inch....does anybody have a rough idea? I drew a diagram to work out the increase in wheelbase, but not sure if that can help with calculating the decrease in seat angle. I also have a Thomson setback/forward seatpost which could counteract any loss of angle (I'm not bothered about the style critics who say that is wrong).