very unique and technical wiring question from shop owner

Local time
2:44 AM
Apr 19, 2022
hello so i am a shop owner and i have been given a fun job to do but i wanted to take things to the next level so let me give you some background. the owner of vintage e-bikes the company came to me with a $35k ebike he built with a sidecar. awesome i know it gets better. sidecar and ebike both have separate motors controllers and batteries they share the same throttle and programming. that being said he wanted it to go faster. so me being the difficult person i am said sure but lets step things up and do something never heard of before. i want to make his bike which currently runs with a 52v 60a using an asi bac500 controller with no display and straight throttle wired in to it. so my plan is to make the bike 60v since it has a undernourished 4000w crystalite motor on it and then this is where things get tricky i want to put two 72v batteries in the sidecar one for sidecar and one for the ebike then i want to create an isolation circuit switch or something of the nature which allows for me to change the bike from 60v to 72v only when sidecar is attached. the goal is for a system that turns off the 60v battery by the regular turning of the key that the ebike has then when i turn the key of the separate sidecar the sidecar battery is turned on for the sidecar and with the flip of a battery isolator switch to be extra safe the 2nd 72v battery would then be primary source for power. i would have to install a small display so the rider could effectively switch the controller to recognize its desired power level. my question is and i think i know the answer but i want to confirm whether im completely insane or whether im on to something really awesome and unique. so my question is with the plan i have mentioned and the proposed wiring diagram im attaching to the thread does this sound feasable. money is not an issue obviously from the price tag of the bike/sidecar. i own a shop in sf bay area and i do really detailed electrical repairs and mods regularly but this one is something i think is very possible and practical so long as its done correctly. if someone could confirm my wiring diagram which is in a laymans format for the sake of anyone being able to pitch in is actually feasable then i would be forever grateful. if anyone gives me a straight answer i i would appreciate it. also if there are any suggestions for added protection to ensure neither battery goes live when theother voltage is running that would be awesome.
thank you,
shop owner
sidecar wire diag.png
They're gonna want the 72V on the bike only. Would simplify life, prevent charger issues. Might actually WANT a bit slower with a sidecar.
Did you know that a motorcycle will typically fit between two cars in adjoining lanes of traffic, but that a motorcycle WITH a sidecar, typically will NOT fit?

ASI controllers can be ..... interesting.

Having both motors tuned to same speed is a challenge for this type of install.
LOL, buy a used nissan leaf for $10k, spend spend $10k on an electric motorcycle that can split lanes, pocket the remaining $15k. Looks cool man, I don't have anything constructive to say, sorry, couldn't resist.