I haven't done one of those, but I think the BBSHD would be worth the extra money. It's a stronger quieter unit. I would also consider getting it tuned to a street legal 750W. Not because I care about such things, but to protect the 8 speed Nexus hub. I did a 750W TSDZ2 on a Nexus7, and had to go to the Nexus8 speed at that power level. It can be tuned up or down as needed later. The Red Stripe version of the Nexus8 is a ball bearing version related to the Alfine MTB hub, and is stronger than the plain bearing Nexus8.
I see a torque reaction arm on the left rear frame stay. I also see a rear side pull rim brake. If it has a coaster brake that won't work any more with a Bafang mid drive. There are heavier Shimano roller brakes with large heatsinks that could probably be installed there. BR-IM80r is one of them, BR-C6000R is the latest version.
https://external-content.duckduckgo....453&f=1&nofb=1
Chain line is tricky with a Nexus mid drive. Single speed chains won't tolerate much offset, and the Nexus shift casette forces the rear cog inwards. This means the front cog must be inset also and results in a large diameter chain ring there. 40t-42t minimum. The Nexus 5 speed E bike rated IGH has some larger cogs available. You will need to remove some extra drive ears to use them.
I would spend some time with the Sheldon Brown Gear Calculator to see what parts you will need. For gear units enter MPH@90rpm.
IDK if the budget will allow this but there is a 5 speeed E bike rated Shimano IGH the SG-C7000 5R. IGH hub. Top gear is direct instead of a bunch of overdrive ratios like the 7,8 speed have.
It might be worth starting there.
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Cargo bike econversion
I’m looking for someone in SoCal (91784) to do an ebike conversion on a Nihola family 2 cargo bike. I want to have a Luna, BBS02 mid-motor kit installed. I’ve read that this conversion can be done, but I know nothing about retrofitting a bike motor. The hub is a Nexus 8 speed, the bottom bracket is 68mm. If this is in your wheelhouse, let me know. rgass@fullerton.edu
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