I have a 4G belt drive gearbox for sale, make me an offer! I didnt like the in frame like I thought I would so I'm gonna go friction drive instead. There is only about 50 miles on the gearbox and is still in new condition. The cover broke on day one however. I also have a rear 26 in 7 speed hub with a custom manic mechanic hub adaptor and 50 tooth sprocket. I had this mounted to the HS 49 cc and it would pull hard and topped at 32mph. Im 220lbs by the way. Take one or both they are just taking up space in the garage.