Hi, I recently acquired an Eddy Merckx Alu Mega and while I realise this is much younger than most bikes in this thread but its size has been torturing me. It sits between a 53 and a 54 from my measurements and according to the sizes I've seen from catalogues. While researching I stumbled upon this thread. I don't think I can post pictures yet since I haven't gone through the 10 posts needed to post pictures. So until I get there, and while hoping I can dig a little further myself tomorrow, here is the information I've gathered on the bike : horizontally, it is written G 7033 and vertically I can read out 97 2223. I expect to see a size under the cable guide as what's written vertically is "quite" close to it but I don't have access to anything to remove it until tomorrow. Does anyone have insights into how I could absolutely tell the size of my bike ?