tsdz2 questions before i buy

hello everybody, i need advice about choosing a motor for my new fatbike
short version :
just bought a fatbike with 100mm BB, want to diy electrify the bike with 48v, and i would prefer a mid drive over a hubmotor .
from all i read about it i have to chose from two options :
bbshd from bafang, -> best to choose the 120mm model and add some "spacers" to make the chainline ok without touching the frame -> great performance but expensive solution.

or

tongsheng tsdz2, much cheaper and decent performance but i can't find a stock 750w version for 100mmbb fatbikes,

- there is a fatbike moded version on an italian shop http://www.shop.future-bike.it/futurebikeshop/prodotto/active-torque-fat/ but it is a lot more expensive : 595€ for a 48v 500w 100bb (best to choose bafang then) or 89€ just for the fat bike shaft extention: + shipping and having to dismount/remount, ofcourse
- on aliexpress there seem to be a 100mm bb version but no info about the power (250/500/750w ?) only that it is compatible with 36/48/52v battery. see here : https://tinyurl.com/y3wrmcz3

questions about the tsdz2 and the existing 500w and 750w versions : is there a real hardware difference or is it only the setup/programation ?
if real hardware difference; is it only the controller or someting else ?
can i buy for example a 36v 100mm bb with hx18 display version and
0 -have it to run ok on a 48v battery with no modicication ? will i fry everything directly or will it run meh untill reprograming ?
1 - just "reprogram" the controller to be 750w ?
2 - buy a spare 750w? controller and just replace the original one with the remaining hardware to run ok ?
for example here : https://tinyurl.com/y5q26662 but they never tell the real power on spare controlers

should i better buy the BB 100mm 48V VLCD5 version ? no problems for custom firmware with the "old" vlcd5 ? no problems to make it behave exactly like or better than the real stock 750w version via firmware reprograming ?

the difficulties, added to the prices make me wonder if ishould not better buy a simpler and cheaper 1500w hubmotor wheel.

what would you recommend ?
thank you

There's two different hardware versions of the Tsdz2 motor, 36v and 48v, of which the latter can be used with either 48v or 52v battery. You could run the 36v motor with 48v battery as well, but I wouldn't recommend it, might not work or last as expected.

Check out this FAQ regarding the hardware and the open source firmware:
https://github.com/OpenSource-EBike-firmware/TSDZ2_wiki/wiki/FAQ

There's also firmware version working with stock displays VLCD5 and VLCD6:
https://github.com/stancecoke/TSDZ2-Smart-EBike-compatible-with-original-VlCD6-display/wiki

thank you ilu for your response.
i will check your links, i allready started to read about firmware flashing and modding.
so, to be clear : i can buy any model that is 48v AND 100mm bb without problem and then just "reprogram" it as a stock 750w ?

i have another question about the form factor/geometry of the motor , maybe someone can answer here :

again : my fatbike has a 100mm bb,
for the bafang bbshd, i read that it is safer to get the 120mm bb version and some spacers to position it correctly on the frame due to the different frame geometries and risks of touching the chainstay and/or having a bad chainline.
is it the same for the tongsheng or is it more forgiving and i can just get the 100mm model in peace ?.

is there any measurements available and/or that i can make on my frame to be sure it fits ?

I don't own a fatbike so I'm not very familiar with their geometry, but I'd guess that the limiting factor is wether the main gear housing of the motor on the drive side fits without the chainstay coming in the way. With my Kona Honzo this was a slight issue, but required only a small spacer so I managed to get the standard model in place. The main gear housing diameter is 68mm, so you'd need to have that much space from the center of the BB. The size is about the same as 34t chainring, but in line with the outer edge of the BB (in the frame, not counting the external BB parts) if no spacers are used.

I'm not sure how the wattage limit works in stock firmware, I've only seen one version of 48v stock firmware available for download, and I think it is 750W. Anyway I highly recommend installing the open source firmware.

I bought from futur-ebike and they shipped without throttle version that cannot be updated to with throttle, so unless you really want without throttle version, make sure you buy with throttle. (It is easy to take it throttle away, and you will get brake sensors capability with thottle, I have heard you can hack brake sensors for without throtle version as well. )

ebird has also with throttle version:
https://www.aliexpress.com/item/32814845175.html

48v,52v is 500W/750W
36v is 250W/350W

and the difference is SW only, so does not matter if you mean to flash it.

But if you order from eBird and do not want to flash OSS software, just ask what wattage these are.

I have 100mm BB version for 100mm fatbike and I would have preferred 120mm, since the left (non chain side) pedal is really too close to "back fork", if you keep your foot in improper angle it can touch the pipes. I recommend 120mm version and some shims (nordlock specially) for spacing, if needed.

I balanced things with Bafang right crank on the right, which will put the right pedal around 1cm closer to chain.

>if ishould not better buy a simpler and cheaper 1500w hubmotor wheel.
Do you want more power or you want toque sensor? 1500W are not geared hubs(at least not any I know of), so they brake some when not driving. They may also have less low RPM torque for not being geared(??) Hubmotor does not require chains being replaced as often.
Do you want a bicycle or a moped?
(KT controller with open firmware supports torque sensor, so this is also an option)