If you are choosing a bike based on stack and reach then note that they are related. The reach and stack are measured from the same point (join of top tube and

If you are choosing a bike based on stack and reach then note that they are related. The reach and stack are measured from the same point (join of top tube and head tube). So if you see a bike that has 20mm more stack and 10mm more reach than another then it actually may have 16mm more reach at the same stack height from the bottom bracket as the smaller bike, (depending on head tube angle) so it's longer than you think.