Last night I took the wife's Rad City ST for a jaunt. Wow! This is a very different ride from my Rad City High step. It is nimble, smooth, fast and sitting more upright, it is very, very enjoyable. I felt like the Wicked Witch from The wizard of Oz riding it! I did 6 miles w/ average speed 16.7 mph and had a great time.
Just another example of how great Rad Power Bikes are! Now, I just can't wait until my Rad Rover 5 arrives!  HeeHee 

My 2020 Rad City has a stock 42 tooth chainring. I find myself using 6th & 7th gear predominately, and sometimes spinning too fast. Top speed w/ PAS seems to be about 24.8 - 25.3 mph. And yes, the controller limiter has been set to 40 kph.
Yesterday on my 12 mile commute, I reached a top speed of 28.9 mph. I'm sure I was going downhill and pedaling my ass off! I do feel the motor holding me back at about 23.5 - 24.5 mph, and I can pedal through it, or just coast and sometimes use Regen.
Today I saw a YouTube video on upgrading the chainring. https://www.youtube.com/watch?v=xbMzksYRdDQ
The guy increased to a wide/narrow BCD 104-46 tooth chainring. He said this increased his top speed. It looked to my like the chain was just a bit short for my likes.
I looked on Amazon and ordered a BCD 104-44 tooth chainring. Hopefully this will give me a few more mph, but most importantly, it will allow me to utilize 5th or maybe even 4th gear a bit more. It looks to be a good quality product for about $30.
https://amzn.to/333s4um
Has anyone tried this approach? What do you think?

In May 2020 we ordered two Rad City bikes, one ST white and my Rad City Std in grey. Yesterday mine arrived. The wife's ST came last week. Put hers together. She test rode it, but no real rides for hers yet!
Anyway, put mine all together last night. Test ride had issues with gear "hunting" for proper gear. Tried screw and turn style adjustments without success. Checked cables for kinks, tightness etc.
This Am test ride had similar issue. Turned it over on the trail.  Tried micro screw adjustments again. No luck. Tried moving the derailleur by hand. No luck, but the "Ah Ha" moment arrived! The derailleur could not move laterally enough to engage the last two cog sets!  Well, big strong Geno and a long screwdriver fixed that problem! Bent the derailleur guard out and Viola'! Problem fixed! Wow, nice and easy shifting now! And is this thing FAST! In 7th gear, level 5 this thing cruises at a remarkable clip! So Happy!
I am amazed at the quality of this bike. Thank You Rad for designing this competent and fun city bike!