I agree with Radar. The F3-8 series were relativley the same with tweaks to the amount of metal removed fron the tubes and stuff like how many bends the chain stays had.
FYI: RC200F4 18": 71 / 74 geometry. 17.9" to top of seat tube from centre of the BB (not inclding the seat clamp) and a effective top tube length of 23". RC200F4 got longer chain stays over the F3 but that was more due to the new drop out design I think.
I have measured these dimensions on my RC200F6 and they are the same.
I pm'd ya back BTW John.
Somerset, like 'Heartbeat' with newer cars!
Retro MTB: 1992 Cannondale M1000 Deore XT M730. 1992 Raleigh Dyna Tech Quantum Deore XT.
Retro Road: 1992 Eddy Merckx Corsa Extra Telekom Shimano 600 STI. 1993 Dyna Tech Ti Campagnolo Athena 8 Ergopower.
Modern: 2004 Wilier scandium Ultegra 6600. 2014 Wilier GTR Ultegra 6800.