Originally Posted by Road Fan

I would try not to ignore seat tube setback. If you have to set your saddle back farther than you like and are not able to reduce stem extension, you could be uncomfortabl ereaching out too far.

One way to approximate it, so you don't have to measure with a plumb line, is to measure length from the tail of the saddle to the midpoint between yur two brake handles, at the front of the brake lever. That gives you a decent picture of the total cockpit length of the bike that fits best, your older one.