- Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
When considering a rear hub motor for a FS MTB, I'd suggsst you take a look at the Grin Tech article on Why Hub Motors. It starts with this discussion of mid-drive motors;
"There are a certain areas where bottom bracket middrive motors are hands down better suited than hub motors. Offroad mountain biking is one great example. The motor weight is low and on the unsprung frame so it has minimal effect on handling even in full suspension bikes. In these situations you are often going slowly uphill through trails with short steep sections and a small motor working through the drivechain in the granny gears of the bike can do this with excellent efficiency. Another example would be say fat bikes riding in sandy beaches or through fresh snow. These are areas where the bike is moving at lowish speeds through high resistance terrain, and the mid-motor in an easy gearing will do this with better efficiency than most hubs drives, while still performing just as well on the faster roads."
From my perspective these points all combine to make mid-drive FS MTBs predominant in the market.
As an aside, Grin Tech also manufacturers the GMAC hub motor referenced in other posts. I have purchased other hub motors from Grin that were excellent. I'm sure their GMAC motor is as well, esp for its intended uses - "heavy hauling and steep hills". One observation, the Grin Motor Simulator demonstrates that the GMAC motors produce peak power outputs well over the 1hp/746W definition of a bicycle here in the States. This limits ebikes over this output to private property or requires them them to be road licensed. Just sayin'.
That's one reason you see bike mfg's using Bafang Ultra units (currently selling like hot cakes) rated at 750 watts. Clearly, they are capable of much more. That's just one example, in addition to the MAC's.
The point is, it's pretty clear at this point nobody is looking at a motor's potential from an enforcement standpoint, including those imported into Canada who's max ratings are even more stringent.
Bottom line, worry if you must, but I'm going to go about my business in a sane manner. I'll become more concerned when/if I see/hear about more frequent enforcement actions on a local basis.