Well, I do know what dimensions I need (I've had my Ridley fitted professionally) and given my proportions, I need a short ETT and a tall stem. With most bikes, if I get the ETT right, the HT is too low and requires a stack of spacers; if I get the HT right, the ETT is too long and requires a short stem.

With the larger frame, I will need an 80mm stem in order to get the bike to fit. That is a bit too short for my liking - I would like a longer stem (I find it helps me with leverage when I am climbing or off the saddle).

And given that I spend a significant portion of the year on a small island and it takes 2 days of travel (by boat and then a flight) to reach civilization, trying out various Lynskey models is not an option. Sadly, my current bike has an integrated headset, so I cant even measure the stack height.

So I would like to try to figure out if I can indeed get the smaller frame to work - which requires getting a rough idea of how much stack height the headset caps add to the HT.

Thanks!