I believe they used that to get rolling and then fire it up 
They need the hub motors in case they come across anything more than a 1% incline
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I actually got it working and itās probably the best controller Iāve used so far. The power itās able to channel is crazy. You hit 30 mph and then anything more than that and it just launches.
Donāt they need those for braking?
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God that is so sketch. XD
Thanks for sharing this!
I actually havenāt had the opportunity to try a set myself just yet. @SirVesa has the most experience with them and they seem to be holding up really well for him.
I have been planning to make my 2 stage gear drive around SLM gears, but itāll probably be late may or sometime in june when i actually start testing them.
Iād be surprised if the sound would be different from regular steel gears. If itās open gear though, yes it will be extremely loud. I canāt ride open gears without a full face helmet.
@CarelessAquarist I got some lasercut chromoly 4130 gears made and those seem to be holding up ok. One of the sets, which I used for 40-50 abusive track sessions is starting to show some wear at this point, but still works perfectly. I do oil it though almost every session (itās open gear). Lasercutting gives the disadvantage of limiting material width to about 6mm, since the laser doesnāt leave a perfectly vertical line, and even if you ask for a wider material, only about 4mm will be the contact area in the beginning which grows to around 6mm over time. I think stacking multiple thin plates wouldnāt work the way it does for belts, as I think precision would be needed.
Hardox is in theory quite brittle i think? I havenāt looked too deeply into that
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Isnāt the surface of the slm gears rough? Do you have to cnc the gear after it is printed? Can you print herringbone gears?@SirVesa
Itās a little rough but not bad at all. They arenāt post processed at all. Herringbone is possible as well.
Before they leave the factory they go through an aging process which is effectively hardening (500c for 6h if i remember it correctly). Itās different from the surface hardening that we do to chromoly gears, and technically surface hardening is more suited for gears, but whether it actually matters in practice still remains to be seen. What does matter is that they are hardened so wear life should be good. Will let Jake to chime in with more details
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I think itās harder but less strong. Did you harden 4130 after lasercutting?
I can also get Hardox 400 and 450 which are less hard but also less brittle. ChatGPT says 400 is best but I can picture wear much easier than snapping.
Youāre right about the downsides from lasercutting, but I think I can get it centred quite well with countersunk sex bolts or manually lining it up then bolting 2-3 layers very tightly together.
I did not harden the lasercut chromoly ones at all. But, I am pretty sure the laser does some surface hardening already. Shitty pinions last me less than a single battery charge in comparison. Probably proper hardening could get even more life out of them, but sendcutsend 4130 chromoly is good to run as is.
On the other hand I did manage to snap half a teeth off my BN M1 AT drive pinion which is case hardened 4130, so its supposed to have a tough and ductile core. But thatās mod1. I did calculate that my full torque went past the gears theoretical fatigue limit so that was sort of expected at mod 1 and ~10nm shaft torque.
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Brakes? pfffft, Pussies.
Now, if they had a drag chute, Iād be impressed. 
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Yeah itās a little rough out of the box. You could probably use lapping compound to clean it up but after an early grease change they look fine. These havenāt been used yet. Herringbones are the only gears Iāve actually tried. Definitely still in testing phase but theyāve been great so far.
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Iām very interested to test SLM Mod 2 pinion gears. The ones I got from Ebay didnāt last at all. And Iām also curious if harder gears sounds louder. 
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I think I have a bad G300 vesc at the throttle connection thing, something might be shorted, I have a throttle handle that I am not sure it works, I donāt do computers, what would be the way to see and maybe diagnose which is the issue in the vesc app? I know I can do the real time monitoring thingy where.
Are you running single unit or dual?
What remote are you using, ppm or uart? Why do you believe itās shorted?
Have you turned on a control mode in app settings?
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Alright, I need to add: it is single, I am using it for hub motor, so I have a throttle handle.
When working everything was fine. I am NOT A PRO at vesc, but I am able to do basic things.
When not working, I am absolutely positive I did all the things right, but I only got half my throttle.
I could only do a proper check up with Cat gro. Sorry.
It mention I might have burned the (UART?) the chip inside the vesc the chip that takes signal from throttle.
I did had my wiring wrong at one point, so not sure if I really broke it, or something else, after the re-build bike was acting very weird throttle vise.
Afraid Iām not skilled enough to help further. If it was working before wiring was done wrong and acting up now, it might indeed be fried? Good luck, diy is quite the journey!