Translating Tri Bike Fit to Endurance Road?

Here we go with another dumb Travis question.

I have a desire to buy an endurance road bike (Cannondale Synapse, Specialized Roubaix, BMC Gran Fondo, etc.), with the intent of doing some really long ride stuff (think RAAM, but maybe solo and unsupported, but that’s another story). Before being fit for my tri bike, I had never ridden any kind of road bike - I was a MTB guy who had never been fit other than the “How tall are you? Yeah, you look like about a medium” Kentucky windage fitting approach. That worked for that. So, when it comes to shopping for the endurance bike, I don’t know anything about road fit, but I want to be very comfortable.

So, with all that said, is there any way that I can use the stack and reach from my triathlon bike and translate that to something appropriate for endurance road? Or should I look at other measurements, like top-tube length and standover height? Would my MTB measurements be more useful? For what it’s worth, my tri bike is a 2010 Seduza in size Medium (stack: 514, reach: 407). It seems that by comparing relative sizes, I’d end up with a shorter reach (~375?) and a higher stack (~570?). Does that seem appropriate? Is it even relevant?

Thanks in advance for any thoughts!
Travis

There is nothing material from your tri bike fit that will help you with your road bike fit.
Find yourself a good fitter and get a fit specific for this application, especially if you want to be very comfortable as you stated.