750w in a 350w case

[Trout]

I just ordered the Bafang 750w front motor, in the description it said it's a drop in replacement for the Sonders 350w. The rear 750w needs the dropouts tweeked slightly to work. I'm getting nervous now, all the research I've done has people useing rear 750w motors for the upgrade. I plan on useing it on the back and single speed. When the description said it was drop in replacement surely they didn't meen for the front.
Is this front motor going to work to upgrade my 350w to 750w on the rear and use my existing single speed? Or do I need the rear 750w motor?

[MoneyPit]

The rear 750w motor is a drop in for the rear 350w. The front 350w is meant for the front: axle length is tailored to much narrower 135mm dropouts and there is nowhere to thread on the freewheel. These motors are fantastic for creating a 2WD Sondors (I built one myself).

The rear 750 has a longer axle that will either work with 170 or 190mm axles. Depending on your Sondors and the motor axle, you may need to spread the dropouts a bit. You can make a simple tool with allthread and a couple of washers/bolts to do that. It is a VERY common modification and you can count on it working fine so long as you do your part.

Worth noting: Luna can build front and rear motors into a new wheel and If they are still using Weinmann double-wall 80mm rims those are much stronger than the stock rims. I built mine before Luna did rear wheels and I can tell you it costs a LOT more for a local professional than what Luna charges to do this work

[Trout]

Thanks MoneyPit.
Crystal clear now.