Bafang Chainline Issue Fix/Lekkie 40T Bling Ring HD Package Install

The main cause of an incorrect chain line is usually due to the setup of the chainring. For example, the chainline may be off by about one centimeter because the offset on some chainrings can be around nine millimeters.

To fix this, a correct chainring with the proper offset needs to be installed. One suitable option is a 42-tooth Leki chainring, which comes with a chain guard and has an offset of 18 to 20 millimeters, appropriate for many bikes.

Installing this chainring requires also changing the motor cover to a slimmer profile one. Depending on the setup, one or two spacers might be needed to ensure proper clearance.

First, loosen the five bolts securing the current chainring and remove it by hand. After removal, the offset difference can be clearly seen—the new chainring moves the chainline inward by about one centimeter.

Next, remove the motor cover by unscrewing six bolts. Care should be taken when prying off the cover to avoid damaging the water seal located inside.

Inside the cover is the clutch ring, which allows freewheeling. If clutch replacement is needed, the clutch ring can be slid off and replaced with a new one.

To remove the gear from the cover, three M4 screws should be inserted and tightened evenly one turn at a time until the gear comes out.

Grease should be applied to the new cover and gear before installation. Since the gear may not fit fully by hand, gently tapping it with a mallet can help seat it properly. Then reinstall the clutch.

If the chainring contacts the chainstay, a spacer can be added to create approximately a one-millimeter gap.

With these adjustments, the chainline should be centered, improving shifting performance and reducing issues such as chain skipping.

Other chainring options are available with various tooth counts and offsets, including 52, 46, 36, 32, 28, and 42 teeth. Larger chainrings are generally better for higher speeds, while smaller ones are more suited for hill climbing.

The stock BBS HD chainring typically has an offset around 18.3 millimeters.