Yes, it is a mid-drive thing with some models that allow for such options. The firmware will take a class 3 bike to class 2, then add in some lag in the name of smoothness when you plug in the throttle. You don't want to do a throttle wheelie or snap the chain off at a start so lag is added. I like them perky and powerful but without bleeding-out the battery quickly so I can get big miles on a lightweight build. I like the 'throttle' in my foot with a torque sensor. Here is a recent build. The idea being, take a $300 bike and make it out run and out last $9400 bikes from stores. This Specialized 10-speed has a gold chain to commemorate the birthday of Mr. T. The display is on the left handlebar. The water bottle is the battery. It is lightweight and has good weight distribution with the motor between the pedals. I chopped off all the connectors and ugly wires. I will add a photo of another recent build with white wires for cleanliness and hygiene. But it is best when you get rid of all the wires, as with the third eBike.
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