Hi and welcome to my listing for a set of three Sinclair C5 Gearbox Upgraded Planetary Gears. Original items are expensive and hard to find. These upgraded gears are fitted with roller bearings to reduce friction and heat build-up that can often melt the gearbox.

These are SLS 3D printed on a commercial industrial printer giving level of detail and strength superior to that of any home printer. This ensures uniform production with a good mesh to the outer gearbox casing. 

Bearings are fitted in an asymmetric manner. Fit bearing side down to the main gear.

Several sets now being used covering more than 80 miles with no failures so far (12v - unmodified). Also used in the C5s featured in Topgear (S32E2) ridden by Chris Harris and Freddie Flintoff.

Greasing - Be sure to use a non-lithium based grease. Recommend 'Mobil Mobilith SHC100' Grease or equivalent. Planetary gears and gearbox outer should be greased as well as internal bearing of planetary gears.