Originally Posted by
Sy Reene
I tried to figure out what you're referring to as the "advice" on the VN site. The size calculator for the Deveron yielded the below results.. Are you oversimplifying the VN "advice" to just inseam? The website's calculator yields a 52cm bike ok with even the 80cm inseam plugged in.

Sy, I'm not permitted to post links either here or in a private message.
If you go to the specific page for customizing the Van Nicholas \ Tour \ Deveron (disc) and scroll down and click on the downward arrow, you'll arrive at a link to Customize there. Start creating your own design and you'll be prompted with first choosing the frame size. In that box there will be frame size advice.
Since I'm allowed to upload pdf files, I took a screen shot showing the frame size advice for someone who has an 89 cm inseam; I have an 81 cm inseam.