Originally Posted by
Samuel D
Read this (PDF) and apply it to the bicycle you currently have, replacing the stem and possibly seatpost (for more setback) as needed. If you can’t get there, you’ll know what to look for in a new frame. If you get there and don’t like the look of the result (overly tall stem, too much seatpost showing, etc.) you’ll again know what to look for in the next frame.
Fitting is not a black art although the gurus would prefer you thought that. Most of what is written online about fit is wrong; see the above PDF for the real McCoy. Paying a guru is unnecessary, not least since most of them fit everyone as if they were fitting a 400-watt racer. A large range of frame dimensions may be accommodated by stem, handlebar, and seatpost adjustments, such that there is no perfect frame size (except aesthetically if you’re opinionated or trend-obsessed). High comfort on a day ride is attainable for most cyclists, but most middle-aged, recreational cyclists don’t ride enough to get comfortable in any but the most relaxed position. That is not the fault of the bicycle.
Good post, good PDF. That's how I do it and my usual advice also.
Answering the OP question, I rode a lot, and when buying a new bike I go to the bike shop, pick a likely frame, put it on their trainer, and have the sales person swap parts until my fit matches the characteristics noted in the above PDF. Of course that was after figuring out all the stuff in that PDF on my own by seeing what worked over the years. It helps to have a mirror or at least a sales person who knows enough to observe your position.
I would add a couple things to look for which I find very helpful. Hands on hoods, back straight and elbows bent, my upper arms make ~90° angle with my torso. Hands on hoods or in drops and forearms horizontal, my elbows are just in front of my knees when pedaling, no overlap. Both the upper arm thing and the elbow thing are true at the same time for me, may not be for you.