Replaced the big ring with the 60T bad boy shown in the below photos. Didn't have to remove the crank arm and spider, so the installation didn't take very long at all. This new ring is a "narrow/wide" type. The teeth are taller to lessen the chance of the chain dropping. Since the ring doesn't have a built-in guard on it, I will now be able to manually place the chain on the inner 44T "get me home" chain ring. Hope the ring helps increase the top speed of the trike a little.
 
 
 

About 2,650 miles on the drive, now. The driveline locked up twice, yesterday. Was thinking: Uh oh, the plastic drive gear is failing. Later, noticed the electronic shifter wasn't shifting through all the gears. This morning, pulled the trike under a shade tree and checked out the driveline, which had an unusual amount of resistance to movement. Discovered the chain had come off the derailleur's jockey wheel and was dragging on the top of the cage. Put the chain back on the wheel and moved the chain on the proper cassette cog (aligned with the jockey wheel). Fine-tuned the shifting, using the Archer on-line app. Driveline drag is now normal and shifting is perfect. Glad I didn't use excessive force to overcome the locked up driveline, otherwise I could have turned the derailleur cage into a pretzel (Been there, done that).

The drive developed control problems with about 3,450 miles on it. It's still giving assist, and the throttle works, but it's difficult to get the assist above Level 1. And when I do get it above Level 1, it's difficult to get it back to Level 1. It's just not responding to the + and - buttons on the display like it should. Manipulated the cable connection between the display and the controller, then took the trike on a test ride this morning. No change, so I ordered a new $60 controller from ECO Cycles. It's already in the mail. It appears I'll be able to replace the controller without removing the drive.  
 
Tongsheng uses the same motor for all of its drives. The controller is programmed to the desired power rating (350 w, 500w, or 750w) by the manufacturer, or supplier in ECO Cycles case. So, in the future if I wanted to change my 500 watt drive to 750 watts, I would order a new controller programmed to 750 watts by ECO Cycles.
 

Quote from bwand on Aug 27^th, 2021, 7:29pm:

 
I've been charging my 48v rated battery to 55.1v, since February, with no discernible effect on it. It's a large battery, so doesn't have to be charged as often as a smaller battery. Never thought about it, until now, but that's another good reason to go with a big battery. Rated battery life is usually 800 to 1000 charge cycles. Going with a big battery might be more economical in the long run.

Couldn't order a motor and another controller, because ECO Cycles' new website is still partially in transition. So, went ahead and ordered a new 500w Tongsheng drive kit from ECO. I planned on leaving the old display in place to keep from having to remove a bunch of wiring. When I connected every thing up to test the new drive, and pushed the "On" button, the display acted up like it did with the supposed failed motor and controller connected to it. Replaced the old display with the new one. When I pushed the "On" button, everything was normal. Secured all the wiring, then took the trike for a test ride. Drive operated perfectly. Apparently, the source of the problem with the old drive was the display. I have the display mounted on a carbon fiber "Tee" that is anchored to the left steering lever. It's subject to a whole lot of vibration at that location, probably more than it was designed for. It's my theory that vibration killed it. It's actually designed to be installed on a bike's handle bar, centered on the bike's head tube. It would be subjected to a lot less vibration when mounted at that location. Guess I'll order a spare display when the mileage on the new drive approaches 3,400. The VLCD-5 display is not expensive (Around $50).

Quote from Lowdown on Oct 1^st, 2021, 3:12pm:

 
I'm guessing the average E-bike rider doesn't know he/she is not covered by their homeowner policy.