When I got Terrie's ICE Adventure HD, I put a Bafang BBS02 assist on it, having ridden Dave Rothgeb's trike with that assist a year or so ago...  We bought the parts from BafangUSADirect, for about $1000, and John's installed it.  Now that we've had it a couple months, I thought I'd make some notes about our riding experiences with it....
 
* You set a particular maximum speed (apparently you can go above 25mph...), and also set how many steps you want to have -- 1-3, 1-5, or 1-9.
 
* The unit actually acts as a speed controller, as opposed to a "torque sensor" responding to your push the way the Copenhagen works.  A "1" setting attempts to get and keep you at the 10-11 mph range, with the other steps being a percentage between that and max speed setting.  It seems to resist a push to go faster, although it doesn't resist faster downhill speeds.
 
* We've been using it with 9 steps to a 24mph max -- so a "2" gets her to 11-12mph, "3" is 12-13", "4" is 14-15", etc...  So the motor works to get you to a particular speed, and you adjust your gearing so you're pedaling at a comfortable rpm to keep that speed.  The "9" step setting gives you good 1-2mph adjustment capability when you're riding with others.
 
* When we're riding together and she starts lagging behind, I just say, "Kick it up a notch or two!" and she's back up with me...
 
* The assist is particularly helpful when starting from a stop... there is also a throttle overdrive that can be used from a stop, which requires no pedaling.
 
* The assist will try to keep you at speed, especially uphill...
 
* The added weight of the motor and battery actually help the stability of the trike in turns, lowering the COG.
 
* If you're considering e-assist, go for the biggest battery (amp-hours) that you can get -- weight of a battery is irrelevant with a e-assist, and it's better to have longer battery life...  we went with the 17.5 Ah "jumbo shark," which appears to provide 50+ miles of use.  YMMV.
 
Paul

Just a little faster and you could go back in time. Just need that 1.21 gigawatt battery.

For anyone who cares,  I'm getting 70 plus miles on a battery charge.  I'm still sitting 2 bars but I'm too chicken to run it all the way till empty.   I'm somewhat conservative with it and it's pretty flat overall.

I got the big one....😁
 
Quote from jayg on Nov 11^th, 2019, 9:25pm:

That's the one!

Mac.. I have over 6000 miles on the Day6 and have had no problems yet. Don't know what number it is. But it sure helps going up hills and a strong head wind.

The Bafang continues to perform without issue... although there have been a couple times where the motor lock ring has loosened up, allowing the motor to "rotate" slightly against the derailleur post.  Tightening and locktite fixed this -- Greg had the same issue a month or so ago.
 
Terrie is definitely having fun leaving me behind (briefly) when climbing hills...  and she is doing 30 mile rides with still 60% or so left on the battery.