Auto-plaza Washer Set for Bafang BBSHD Mounting

The maker's own description is short and consistent on this point: the washers are placed on the motor shaft to hold the motor in position, and they suit an adjustable bottom-bracket length set-up. Nothing in the set touches the electronics, and nothing needs wiring.

What the set is and is not:

• Is: four metal spacers for Bafang BBSHD, BBS01 and BBS02 motors, rust-proof and wear-resistant.
• Is: a way to take up width between the motor, the frame and the fixing hardware.
• Is not: a water seal for the controller joint. That job belongs to a rubber part like the FILFEEL controller gasket.
• Is not: an adapter for press-fit shells or shells outside the kit's range.

The BBSHD mounts through the bottom bracket rather than to a special frame mount. The motor's tube slides into the shell from the non-drive side, a fixing plate goes on from the drive side, and lock nuts clamp everything together. Everything about how well that clamp holds depends on the parts stacked on that tube.

Auto-plaza lists the size as universal and does not state inner or outer diameters. Measure your motor's shaft and your fixing plate before counting on a fit; the full stack is drawn in the install guide.

That matters because the clamp is the only thing resisting the motor's torque. The BBSHD pushes up to 160 N.m through the cranks, and the motor housing wants to rotate around the bottom bracket every time you climb. If the stack is loose, it will.

Cases where a spacer earns its place:

• Narrow shells near the bottom of the kit's range, where the tube is longer than the shell needs.
• Frame welds or paint that stop the fixing plate seating flush against the shell face.
• Clearance tweaks where moving the motor a little sideways keeps it off a chainstay or kickstand plate.
• Worn contact faces on a frame that has had several motors fitted over the years.

A loaded cargo bike or a trail bike hammering up rocky climbs puts the most strain on this joint. On those builds, check the stack again after a week of riding, when paint compresses and the motor settles.

On the 100mm and 120mm versions the stack and chainline both need thought, and the fat bike guide runs those numbers.

1. Remove the cranks, chainring and lock nuts if the motor is already fitted, and slide the fixing plate off.
2. Clean every contact face: shell ends, motor shoulder, fixing plate and the threads.
3. Dry-fit the stack with the fixing plate and nuts, and see where the gap sits. Add washers there, one at a time.
4. Keep washers flat and square on the shaft. A tilted washer turns a firm clamp into a slow leak of preload.
5. Set motor angle so it sits snug under the down tube with clearance to the stays.
6. Tighten the inner lock nut firmly, then the outer one against it, using the proper tool.
7. Test by standing on the pedals with the brakes on. The motor should not move at all.

Use the fewest washers that solve the problem. Every extra layer is another joint that can settle, and too thick a stack can push the chainring out of line with the cassette.

After the first ride, recheck the lock nuts. Most motor-rotation complaints appear in the first week, not the first year, and a quick check with the tool saves a scratched chainstay. The clicking-noise guide helps separate a loose mount from an internal fault.

So check the result, not just the clamp:

• Chainline: sight down the chain on the smallest and largest cogs. Both extremes should run without scraping the ring or dropping off.
• Crank clearance: the non-drive crank should clear the motor housing and the frame.
• Chainstay gap: the ring and chain need space from the stay under load.

If chainline is the real problem, an offset chainring is the better fix, and the chainring guide compares ring offsets and tooth counts.

Three checks keep this from being a wasted part: make sure your motor is a BBSHD, BBS01 or BBS02, that the washer bore will pass over your motor's shaft, and that your issue is spacing rather than sealing. The set comes with four pieces, enough to build up a small gap or split spacers between sides, and a six-month warranty covers the hardware.

For water getting into the electronics, the answer is a rubber gasket at the controller joint, not metal washers at the bottom bracket. The FILFEEL gasket is that part, and the controller guide marks where the seal sits.