Looks like they have 3 chainstay sizes available, from 430-440 on the AM150, which was the one I considered a few years back. Pretty sure it was 1 or 2 back then, but either way too short for my tastes.
For a custom frame, I think that's much too limited when you are talking reaches from 415- 535.
Our frame-only option comes with a Fox Facotry X2 shock 205/60, delivering 150mm of smooth, controlled travel. This bike is available to buy through the cycle-to-work scheme
www.athertonbikes.com
Anyways, I'm exicting to see what they bring to the table for their e-bike.