Originally Posted by aceSSone

IMHO, Unless you have back or neck problems most ppl can ride a road bike. Looking through your eyebrows instead of the natural full face forward helps the neck. It's more about your position on the bike that helps make it comfortable. I like to give my take on how to ride a road bike when I do fits.
Try this:
Stand up, bend over at the waist until your back muscles are relaxed and your core takes your torso weight. About 75°- 80°. Hold your arms out with 90° elbow, like you're on a road bike. Lift one foot. Feel how your torso weight is transferred through your core and legs to the floor (the pedal). That's pretty close to what your full speed position should feel like. Say in the 53x15.
Greg Lemond wrote "The Complete Book of Cycling" and stated during his cycling clinics riders couldn't get in the proper position if the seat tube angle was greater than 73°, (page 132). Most bikes today don't have 73° seat tubes. They (mfrs) are more interested in tight race geometry which means 74° seat tubes it gets worse the smaller they go, it also depends on size and manufacturer. Just look at their geometry charts. The position is related to the BB. When they stand the seat tube up, they also move the BB back. A lot of ppl don't take frame geometry into account. They're more worried about brand status.
Keith Bontrager, frame builder wrote an article called The Myth of KOPS. When he builds custom frames, he centers the rider center of gravity over the down pedal power stroke.
The position I describe does just that. My training recommends a saddle setback of 10% of saddle height. But there is a variation bc of saddle length.
In order to get this position the saddle center needs to be at 73° and the bars need to be moved back. Being back lets you spread the work out more on your quads, the power stroke starts sooner and gives you a better saddle anchor and torso weight anchor to power the pedals from. The fads of long stems and forward saddles in combination with the new geometry really ruin the power position I describe. I believe most riders are on a bike that's too big for them. The top tube prevents getting back far enough. And then shops that do KOPS move the saddle farther forward. That moves your CG closer to the front which weights your hands and prevents weight transfer to the pedals.
Keith Bontrager, frame builder wrote an article called The Myth of KOPS. When he builds custom frames, he centers the rider center of gravity over the down pedal power stroke.
The position I describe does just that. My training recommends a saddle setback of 10% of saddle height. But there is a variation bc of different saddle lengths.
So the best way to get a stack measurement to prevent a lot of spacers is to get a dynamic (pedaling at speed in describe position) stack and reach fit. When you do, have them keep the saddle center at 73°.
I just describe what I think. Try it, if it works for you, even better. I'm 5'6" so a small bike. Today's bike geometry is not for short riders. The position and fit I describe is the same for tall riders but their frames are closer to 72° 73°, so they have a built in advantage.

Hope that helps.