Seeing RAD Mission single speed bikes coming up for sale... Thought about getting one on the cheap to upgrade to multi gear and color digital control box..

Anyone done that yet?

I sold mine specifically BECAUSE it had a proprietary derailleur mount/chain tensioner. It's not upgradeable, unfortunately.

Not a bike worth upgrading if you could. The bike is a bike to ride as is so you can get a sense of what you like and don't like and then find a bike that fits that criterion better or go to your local shop and find something more satisfactory.

I looked at their web site and the bike isn't listed.

They did away with that model. Tested it once but went with 2 7 speed bikes instead since. One came up for sale locally and for cheap price I thought I might purchase it but subsequently finding would be too expensive with needing too many new items - probably would not fit. I already have a spare control box, etc...

I had one and rode it as is. It was light, reliable, handled well, and I got 30 miles of range. Single speed was not a problem, it had a throttle.