Luna bikes e-assist fatties

I did a Luna/Bafang BBSHD on a Surly Pugsley, used it for packing in snow-trails and general fun farting around. Worked great, then someone came in the shop and bought it off me.
Bafang is one of the biggest ebike motor manufacturer and their products are well regarded.

One thing to pay attention is which battery to use and where to mount it. Ideally you want it on the down tube and not in a backpack.
I've had good luck with two batteries from them and am currently building a BBS02 system (my wife grabbed the last one). Reportedly Bafang produces 850,000 motors per year, so should know what they're doing.
I've purchased 3 mid-drives (one Bafang and 2 Cyclones) and 3 batteries from Luna. Generally a very good value. Customer support is somewhat psychotic; depends who you wind up talking to.

Even though I've had several serious technical problems I'll continue to purchase from them; it's good practice for a DIYer to figure things out on your own.

Zero trouble (that I can remember) with the BBS02 other than it's hard to gear really low.
Tis true, getting a small chainring and good chainline is tough with the Bafang (ERad/Luna and others) mid drives.
Backpack batt vs downtube have their pros and cons. For the most part people prefer not to carry a backpack. But when your bike is already 40+ pounds it feels better to take that extra 10lbs off the bike and carry on your back. Just my opinion, your milage may vary.
I use 11-17-28 gearing with 8-speed spacing and have an excellent chainline (the 17 is straight) with a 30 tooth Luna front ring. Top speed is lowered to 20-24 mph, but there's enough gears for the trails that I ride.
I have had good luck over all with them. I have had a BMS go bad and take out 20 cells in the 52v 20ah rectangle pack, Led handlebar light stopped working and had 2 triangle bags rip apart when the bike fell over on it's side.
Now I can ride after over 12 yrs off the bike. This is one bad ass coyote chaser.

bafang ebike kit on mountain bike.jpg
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I put a BBSHD on a fat bike I bought from Sears, and love it. No moutians in Iowa, but I ride off road whenever I can. 1500watts.. = fun!!! ( im 64yrs old )
Are these class 2 assisted set ups?
Is there a throttle and pedaling is optional?
My local trails only allow class 1.
I have a Santa Cruz HighTower I would like to convert to a class 1 pedal assist
Bafangs kits are cadence PAS and throttle. Cadence sensing PAS is not as efficient as a Torque Sensing PAS and the kit I like that has this feature is the TSDZ2. It also has a throttle option which quite frankly is only worthwhile to help get going enough to get enough pedal stroke in to activate the PAS. But for that it is well worth having on the bike. Getting a heavy e bike going in the middle of a hill is hard to do but about 5 seconds of throttle and a few pedal strokes and off you go. Or you can use it to walk the bike up if all is lost. If you try and use the throttle while moving it doesn't work all that well, certainly not as well as the PAS.

The stock TSDZ2 is 36v but it can be configured to use up to 52v which x 15A is about 780w peak. I only use the eco mode but while climbing steep terrain it has plenty enough power as long as you gear down accordingly. Price is inline with the comparable Bafang unit but the Torque Assist makes it have more user value.

TSDZ2 36v Fat Tire Ebike.jpg
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Trying to e-assist wife's fattie. Anybody try Lunacycles mid mount motors?
Yes, I have the Luna Cycles cyclone 3000 it's a 3000 watt mid-drive motor, they also have the cyclone mini which is 2500watt, but they are not for the faint of heart, you should have some bike building as well as mechanical background to tackle this, because there are no instructions and very little documentation on there website. They do warn you of this before you buy, but they also sell bafang motors as well, but you can get a better deal on if you are buying Bafang motor.