Decision to be made

[HunterRoark]

Dilemma;
New to e-bikes...fell in love with an Electra Super Moto 8i with 27.5" wheels....after discovering Luna...researched installing mid drive.....do-able....aluminum frame, nexus 8 speed hub.....nervous now.....wilI I destroy the bike? Can it handle the torque?
Discovered Lunas All Terrain 500 ....out of stock but....has what I'm looking for. I am willing to wait...figure out how to purchase on limited funds.....what would you do?

Hunter

[Retrorockit]

i would consider a BBSHD 750W version to save that hub. Some people run it 1500W and say its OK. But it's just a matter of tuning to change that and soften up the power application to suit yourself. BBS02 would work also.
2 things to consider. The single speed chain is a big plus for strength, except they're fussy about the chainline and the Nexus shift casette pushes that in a bit. Probably a 42T inset chain ring will be needed. This chart will get you started on the rear chainline. Try to match it at the the front +/- 3mm.
https://www.sheldonbrown.com/chainli...rnal-gear.html
The other thing is the Nexus has several overdrive gears that no casette has. This could result in some long gearing especially with large 27.5 tires. There is a new Nexus E bike 5 speed hub and all the indirect gears are overdrive. They make some larger rear sprockets for them that may be needed to get a useful top gear, and low enough 1st gear for creeping around pedestrians. They have 24t,27t, and 30t options. They have 6 drive ears instaed of 3 that normal Nexus has. so some grinding may be required if you need to use them.
Here is a gear calculator with the Nexus hub in it. Choose speed at 90RPM for "gear units", and your tire size and chainring. It can calculate several cogs at once.

https://sheldonbrown.com/gear-calc.html

SG C7000 5D is the hub that has the larger cogs available. But I ran the gears and 19-21T x42T both look good.
I would plan on adding larger brake rotors, and with no suspension fork a top speed of about 25-27mph. A suspension seat post is a common upgrade around here also.
The upright riding position is good in traffic, and the tires are big enough to provide some suspension if you keep them below 30psi. Not a bad starting point for an electric cruiser.

[HunterRoark]

Truly appreciate your detailed input. I am seriously considering purchasing a complete Luna All Terrain 500 e-bike instead.
Thanks again,
Hunter