Also, my new 3-speed sprocket has arrived and I plan to tinker with it over the next couple of days. Since I do not yet have an upgraded motor, I am hoping (betting) that this sprocket will fit the RR1 even with the offset spacer. I believe it will because the new 3-speed sprocket is approximately the same overall width as the stock single-speed freewheel.
If it fits, then I plan to purchase a derailleur and shifter to see if I can give the RR1 at least 3 speeds, which I believe will still constitute a noticeable improvement over a single speed. The new sprocket is a 14-17-20t as compared with the stock 16t sprocket. If this works, I should see a small benefit on the low end (for climbing hills) and the high end (to help reduce so called "ghost pedaling" at higher speeds). If this doesn't work, not a big deal -- this new sprocket cost just $16 (including free shipping).
My long-term plan is to eventually perform the full RR1 makeover -- new motor, controller, display, and 7 shiftable gears. Since I cannot find either a 3-speed shifter or rear derailleur, I am going to purchase the 7-speed components, initially, and again hope that I can make them work with my 3-speed sprocket (I just need to limit the derailleur travel on the higher gears).
Also, for what it's worth, I have already installed a front suspension fork on my RR1, which I purchased directly from RPB for $150 USD -- this is the same suspension fork that RPB uses on the RR+. I mentioned my purchase to someone else in another forum, and they contacted RPB to order/purchase the same fork. However this person reported back that (for some reason??) RPB would not sell them this fork. Maybe they sold one to me only because I also own a RR+, but who knows??? At any rate, there is at least one other supplier of a similar fork -- Biketrix out of Canada, but for $250 USD (or anyhow the last time I checked).
But if you can get your hands on one, mounting the front disc brake to this fork required some minor modifications. But now knowing what's required, I could probably repeat this entire installation in about 30 minutes -- everything else fits perfectly. The one side effect is that since the new fork is about 1" longer than the stock rigid fork, the new fork raises the entire front end of the RR1 by about 1" -- only barely noticeable from an aesthetic standpoint. Yet I also had to shim-down the center kickstand by about 1/16" to account for the rise. Btw, the center kickstand may also present a problem when adding a rear derailleur to the RR1 -- I've been told by RPB that this is the reason they switched to a side kickstand on the RR+ -- the center kickstand interferes with the lower-hanging derailleur cage (as compared with the stock chain tensioner on the RR1). So, in short, if you add a 7-speed derailleur to your RR1, you may be forced to switch to side kickstand (although I suspect that some short-cage derailleurs may avoid this problem).