We made 10 of these ISO disc brake to 130mm BCD sprocket adaptors today. These were designed out of necessity for my KMX [production] E-trikes. However, they will work for pretty much any disc to sprocket applications.
I went with 130mm BCD for two reasons;
#1 I wanted a higher tooth count than available for 110mm BCD. I wanted 50 plus tooth rear sprocket to be able to run single stage drive unit with correct ratio. This saves the customer money over having to run a two stage drive.
#2 Johnrobholmes is making a 110mm BCD adaptor. I did not want to step on his toes. So, it is good to have multiple options anyway.
The adaptor is offset exactly 1/2 inch (12mm) inward from the plane of the disc brake flange. This gives a proper chainline for most applications.
They are all CNC machined from 6061 billet and are tough as nails. The minimum wall thickness is 4mm. They are designed for absolute rigidity.
These adaptors are $49 (for those who may want one).
Anyway, I want to thank Miles for his help. I owe you one, Man!
Oh, keep your eyes peeled, I am machining lots of new parts right now. They will be shown very soon.
1% of the world's population can think "Outside the box". The rest are firmly stuck within the box. Where are you?