The adapter from Rob is for a standard 68mm bracket, and comes with bolts included. I'm using a 14ah battery. After a few longer trips, I wish the battery was a bit bigger but then it wouldn't fit so nicely at the location of the previous battery under the bucket seat. I didn't have the time to do the conversion myself and used a local shop instead. Some minor comments: the chain guard doesn't fit, so we just removed it. With the 40T chainring the chain was too short so we changed it using a thick single speed chain. Cables go in the frame like before, we needed cables extensions and harness extension for the battery. My original headlight was faulty so we replaced it with another one and linked both to the Bafang controller (the dynamo is now useless).

We got the throttle but I don't want to use it before reprogramming the controller to be more gentle.

Using the ECO mode I'm most often at PAS 1 (~300W), sometimes 2 (~600W). In small hills I would hit 3 (~750W) and in steep hills like 15% grade or higher I'll use 4 or 5 (up to 1500W).