Tongsheng TSDZ8 750W 48V teardown, disassembly

Motor's stator is pressed into the housing. Unlike TSDZ2 there's no air gap between the motor and the housing. Cooling efficiency should be greatly improved.

Ratchet style crankset one-way bearing should have better longevity.

Another one-way bearing for the motor is very similar to the one used in TSDZ2 motors. However, it has a large diameter and is supported by another bearing mounted just below it. This should result in better longevity.

The controller is a separate part of the housing. It is easily replaceable. Cooling should be improved by that design as well. Electronic parts are covered by the insulation to prevent any water damage.

Torque sensor is very similar to TSDZ2. The main difference is the addition of the thrust bearing to the inner side which seems to be a better solution than nylon spacers used in TSDZ2.

The housing has locating/dowel pins built in. It's easier to assemble the housing parts.

Housing parts are sealed by paper/sheet gaskets instead of rubber ones. They are more prone to damage.

There are bearing on both ends of the crank axle. Covered by seals. Play on the axle is greatly reduced compared to TSDZ2 and TDZ2B. This should improve the longevity of the bearings and other elements.

The nylon gear is larger than in TSDZ2. It should be more durable and less prone to damage.

The original chainring is 44T and has an offset of 16.3mm. It's heavy but made out of rather soft metal. Doesn't seem to be very durable. It weighs 416g including the plastic chainring cover. Soon we will have a 130BCD adapter with an 11.4mm offset. This will allow for mounting 130BCD narrow wide chainrings starting from 38T.

The right crank arm is straight. The left one has an offset. This should improve the Q factor. TSDZ2 had two crank arms with an offset. This resulted in the right crank arm being positioned more to the right from the bike's bottom bracket than the left one.