Originally Posted by Moisture

It would be helpful for you to know what to look out for beforehand so you are not going into there blind.

As a general rule of thumb, the top tube length (sometimes refered as effective top tube) dictates how close or far you will be sitting to the bars. The reach determines how far the cranks are from your handlebars. Don't forget to consider standover height.

As an example, I like an upright riding position. To achieve this, I tend to feel best on a road bike whilst using a short stem and flat handlebars. I like my reach close so that my butt is hovering directly over the saddle when pedalling. Im pretty top heavy, so when I lean forward I feel like I'm not able to weigh the rear axle properly for stability.

If you prefer a more bent over riding position, you're still better off with sticking to a fairly short reach (like 385mm) and playing round with different stem lengths to compensate.

If you are riding with your saddle higher than the bars in any amount, chances off you're not achieving the best performance and comfort you can .