20” vs. 24” Trail Tracker: PAS Swap?


Might be a better question for a DIY forum but thought I would start here.

My wife has a 24” Trail Tracker (PAS, throttle, 350W nominal Dapu motor) that’s proving to just be too large for her. She gets proper leg extension once on the bike, but getting on and off the bike is just too difficult for her.

There’s an old discontinued 20” Trail Tracker (throttle only, 500W nominal Dapu motor) for sale in my area (essentially new condition). The smaller frame on this 20” Trail Tracker would fit her much better. So while I don’t really have the time to get into a complicated time consuming parts swap to get her on the smaller frame of the 20” Trail Tracker, I wanted to at least explore the option.

The best option would be to try to incorporate the PAS from the 24” bike on to the 20” bike, she ride the 20” bike, and then just keep everything else for parts. A lot of the parts are interchangeable. I’m not really sure how complicated that would be. Has anyone tried anything like that?

The biggest problem with this will be the programming. While the 20” TT bike actually has a larger 500W nominal Dapu motor, it doesn’t have PAS and it’s been speed restricted to 12mph as it was targeted to kids. I assume the programming is in the hub (which I could not swap), not the basic display (which I could swap). So for the PAS to work on the 20” bike, and to increase the speed restriction to 20mph, I would likely need to find a way to flash the 20” hub with the programming for the 24” hub. Might not be a feasible way to do this without changing the controllers to aftermarket solutions.

Anyone have any thoughts or suggestions as to options?
She cannot stand over the top bar on the 24” Trail Tracker. The 20” Trail Tracker frame fits her better. The reason for considering a PAS swap from the 24” TT to the 20” TT is because the 20” TT does not have PAS (it’s throttle only). Thanks for the video link, I didn’t realize you could change the top speed of the Pedego’s in Setting 2. Pedego’s literature implies the 13mph limit is a fixed setting (since the 20” TT was primarily targeting kids).

Pedego tech support did tell me yesterday that it’s possible to add the PAS from the 24” TT to the 20” TT, but it would be a major undertaking with no guarantee it would work. So that idea has been scrapped.

The crank forward flat frames are interesting but since they’re cruiser bikes they’re fairly large frames and based on their sizing suggestions they would likely still not work for her small size, plus they’re really not suitable for the forest service roads and trails near us.

At this point I’m contemplating a step through LMT’D ST from Ride1up (smaller Class 2 step through with torque assist), but might hold out until more details are released on upcoming releases of 2023 20” fat tired ebikes. There are a few that could work for her size, but right now most are cadence sensor PAS systems with rather crude 100% on/off power delivery that feel more like dirt bikes. If any 2023 Class 2 20” fat tire models are equipped with torque sensors, then that will likely check all the boxes for her. Seems like all the manufacturers are moving toward PAS systems with torque sensors, which we both prefer.

Thanks for all the feedback.
FWIW Do yourself a favor before excluding a frame, and actually sit on the different styles in local shops. We ride out flat-foot frames everywhere.
Would you consider a Pedego Boomerang, with 24” tires?
super deep step through and the smaller wheels bring it lower to the ground.