State of the hackable motor

boudin

100 mW
Joined
May 4, 2022
Messages
44
Given the current unfriendliness of Bafang's CAN bus implementation (and, presumably, the similarly locked-down and otherwise uninspiring offerings by Bosch, Shimano, and others), I'd like my next bike to be a build involving reasonably manipulable electronics. Doesn't need to be compile-your-own-firmware (although I'm down for that), but the ability to tweak wheels, speeds, and assist levels would be really nice. I know my way around a soldering iron, but well enough to know that I'm not likely to spend my evenings designing and assembling PCBs.

What's out there? I see mega-threads on Cyclone and Tongsheng offerings, and there's "always" the BBS02/BBSHD (so long as Bafang doesn't transition those to CAN as well), as well as some discussion of Cyc. What else am I missing?

Some parameters I'd like:
* Mid-drive
* Software configurability
* Light-er weight (under 10lb would be great)
* 500-1500W (higher is fine so long as efficiency is there)
* 48V preferred, 52V acceptable (battery density)
* Frame integration is nice-to-have but repurposing an old frame works too

For example: right now I'm considering repurposing an old Novara hardtail I have to serve as a gravel/light-trail build. Luna's upgraded BBS02 looks nice, but so does the open-firmware TSDZ2 from eco-ebike.com. Does anyone have (or have used) both and can provide constructive comparisons? Obviously weak parts (like gears) would definitely be replaced with more robust alternatives, but I'm not even sure if these are the right options.
 
boudin said:
For example: right now I'm considering repurposing an old Novara hardtail I have to serve as a gravel/light-trail build. Luna's upgraded BBS02 looks nice, but so does the open-firmware TSDZ2 from eco-ebike.com. Does anyone have (or have used) both and can provide constructive comparisons? Obviously weak parts (like gears) would definitely be replaced with more robust alternatives, but I'm not even sure if these are the right options.

Your weight may be a consideration for the TSDZ2, due to the reputation of breakage of the bottom bracket, which isn't a part that can be replaced with "more robust alternatives".
 
E-HP said:
Your weight may be a consideration for the TSDZ2, due to the reputation of breakage of the bottom bracket, which isn't a part that can be replaced with "more robust alternatives".

Thanks, excellent data point! Fortunately that build would be for someone that weighs significantly less than my 100kg, but it warrants consideration anyway. The amateur machinist in me wonders what the breakage mode is - whether it's shearing, cracking at a stress riser, etc.

[edit]
This comment seems to summarize the weaknesses I'd have expected.

Chalo said:
Surly bikes are top notch, no problem there.

TSDZ2 uses a smaller diameter bottom bracket spindle than anyone else in the bicycle industry, makes it from low strength material, and includes a snap ring groove at the point of highest stress. Compared to that design blunder, their electronics and software shortcomings seem benign.
 
boudin said:
The amateur machinist in me wonders what the breakage mode is - whether it's shearing, cracking at a stress riser, etc.
Most likely primarily stress riser cracks propagating thru; the ones I have seen pics of here on ES look lke spirals or diagonal fractures along the length; it's because it has hollowed out areas and also recesses for circlips to secure bearings/etc.


Like this thread:
https://endless-sphere.com/forums/viewtopic.php?f=49&t=115972
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20220505_182247[1].jpg


or this
https://endless-sphere.com/forums/viewtopic.php?f=28&t=79788&p=1512178&hilit=shim#p1512198
20191122_153433_resize_95[1].jpg
 
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