My father is up for making another pair of our dual direct drive style gearbox for Trampa MTB. Currently, we are taking only pre-order with 2-4 week lead-time as we have to order gears and stuff.
Beautiful ! The ground clearance seems really low (compared to belt/chain driven systems) mainly because of the direct drive “enclosure” to keep dirt outside the game ? it’s probably just a visual effect as you are running 12/60T? Do you think there’s a way to increase this ground clearance that could be really exposed if you ride all terrain? Cheers man and congrats to your father. I always like to see such craftsmanship work.
The biggest problem is the size of main gear and gear ratio. Currently its 12/60T and it provides 5:1 ratio the problem comes up if want to go small on big gear you need get smaller motor gear which is maximum 10 tooth so I can get like 36 tooth smallest to get decent 60km/h max speed but then you will need 130kv motor which is hard to find APS has 6384, then there is another problem that motor gear is only 8mm and outer diameter there is hole is 15mm so its only 3.5mm of meat on mount so it will be hard to bore it out and make a set screw. The “enclosure” is important because if anything gets in between gears it get stuck and you can fly forward As it happened to me with set screw getting in between but it was low speed as I was going back home after hearing some strange noises. Maybe it’s possible to 3d print the outer shell with place for mounting holes but I guess it will be highly inefficient and will take forever to make such big case.
For motor pulley only 11,12,14T, but the problem will be with the top speed over 60km or you can find <=100kV motors but then max speed drops to 40… It’s a shitty problem more than 14T then its 12mm motor shaft
With your CNC machining skills why don’t you do a inner gear version of this? More teeth will mean less wear and higher torque capabilities plus the motor comes closer to the hanger which gives a more compact kit.