Converting final chain drive parts to final belt drive parts.
Some parts used on chain-drive models can simply be altered such that they can be used on belt-drive bikes. Mullie Motors can provide these services for you.
- Clutch shell conversion: The starter ring gear on belt drive clutch shells is located further out on the shell than on chain drive models. We remove the starter ring gear, machine the clutch shell in a lathe to ensure proper fit, press on the ring gear at the correct location and weld it tight. In addition, we tag the rivets of the clutch shell blocks to prevent them from loosening.
- Outer primary conversion:
The boss in the outer primary for the starter axis bearing sits deeper in the outer primary on belt drive models than on chain drive models. We mill down the boss to the proper depth to be used in a belt drive application. In some outer covers, the needle bearing inside the boss cannot be inserted deep enough into the boss due to the casting. Here we replace the bearing with a slightly narrower one. We also check the rest of the cover for clearance to the starter ring gear (that is positioned more outward). If necessary, we mill down some spots for additional clearance. BTW, outer primaries intended or converted for final belt drive applications can (still) be used on chain drive applications by simple using some extra thrust washers to ensure proper clearance.
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