Recommend Product BAFANG Nylon Gear The nylon primary reduction gear is one of the weak links in the Bafang BBSHDsystem. If you apply too much power while in the wrong gear you can strip them creating a problem referred in the community as "peanut butter gear". Nylon is a necessary evil is because if steel gears were used the BBSHD would bevery noisy. Feature 100% high-quality products Support for replacing the internal teeth of the new middle motor BBSHD BBS02 after 2015. Abrasion resistance, high and low temperature. Gear depth is 3mm, please measured and purchased according to actual conditions. Compatible with all Bafang mid-mounted motors 36 V / 48 V 250 W / 350 W / 500 W / 750 W / 1000 W. Specification Name:BAFANG Type:Nylon Gear Provide Model:Bafang BBS02 or BBSHD Function :Anti Abrasion, High And Low Temperature