Much like what Pete had said, but I find it very easy find the initial X/Y from the bottom bracket to seatpost/saddle tip and take that initial measurement in relation to get the reach and stack, then measure to the bars. As far as setback and length of stem, then add those numbers to the Kickr since you can change the post length or setback. I feel as long as you get the initial numbers and go from there, you'll be good.