RadMini GT

[Altema]

No, this is not a new bike announcement from Rad
I had a situation come up yesterday with my motor making an odd sound. Since I had a group ride in the evening, I decided to pull the motor apart and inspect it. Seems that Bafang is still using weak adhesive for higher powered motors as well, and the magnets separated from the magnet shell. Even after the adhesive fails, the magnets still stick to the steel magnet shell, but the coils of the motor can be strong enough to pull them away in high power situations. I carefully tapped the magnets back into position with a wood block (the magnets crack and shatter easily), then I used Scotch liquid superglue which is less brittle than Krazy Glue. I forced it into the spaces between the magnets, let it soak into all the cracks and crevices, applied it around the perimeter of all twenty individual magnets, then set the assembly in an intentionally steamy bathroom with a fan blowing through it.

I was a bit late for the group ride, but it was well worth it. My Mini usually tops out around 33 to 35mph on level ground, but it seems that the magnets have been separated and shifted out of position for a while, and when they do separate at high speed, it creates internal drag. The ride I attended was actually two rides, with the first one being for families at low speed, and the second one being on the streets in traffic with Sur Ron's and Onyx's and Super73's, along with an Ariel Rider and a Juiced Hyper Scorpion. We still kept the speeds moderate at first, then after some photos and drone shots in a parking lot, the lead Onyx and the Sur Ron's took off. You should have seen the double takes as I moved into the third position, and the guy on the Sur Ron next to me looked, looked again, and looked again. Not only was the RadMini past it's usual top speed, but it was cruising at 42mph on flat ground. I was uncomfortable with it for very long at that speed because the bike had a slight squirm, which felt like the beginning of a speed wobble, but I believe that was due to both batteries in back, combined with the wind resistance of an upright riding position, made the front of the bike very light. I'm sure having only 16PSI in the tires didn't help. Slowing down to 40mph eliminated the squirm, and my top tube battery may come in handy here. Not that I WANT to go that fast, but the good news is that the motor was happy with it. So to the Rad folding bike that still looks stock but has a few surprises, I dub thee "RadMini GT".

[JimInPT]

That's a great story and equally-great info - thanks!  I just have the 35A and Juin Tech hybrid brake calipers, but it made my MiniST2 sorta butch and still stealthy.  The two unyielding hills in my hilly town yielded immediately to that new controller.

[Altema]

Yes, hills become a non-issue with the 35a