I was watching his new video and do not tell me that those are not a new GD prototype 
Module 2, 9T/40T, 10mm axle, 5 holes for the wheel adapterā¦
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I knew it! He picked up a good engineer btw. That guy knows a ton!
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Seems like they are close to be neighbors as well 
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yeh I would move just to have someone like him as neighbour.
Btw the video actually answers my question whether was possible to makae a smaller gear than 12T with number 1 involute gear module 2. Apparently is possible 
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wow thats funny someone actually knows him hahaha
yeah the gears are not perfect but works good until now
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This should be a good video
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Yeh being following him for while. In the field Stefan is one of the few that can actually teach about machining.
How do you find steel on steel for gears?
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Sorri for the late reply I was a bit off the forum the last days 
The gears are nice, steel on steel is quite loud but somehow I like the sound. I first was a bit concernd of heat but it seems to be alright!
There are some things I want to change for the next version but Iam not sure atm how and when.
Things Iam thinking about is:
Switch to helical (expensive, hard to get produced and not that strong as straight teeth. But its not that loud and runs a bit smother)
Thinner teeths maybe from 15mm to 10mm wide.
All stuff Iam thinking about atm. But yeah I will need to test some more before.
Here is a little video of the sound - The teeths still will need some more KMs to ārun inā for a even nicer run.
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No problem!
yeh for sure steel and not metal gear helps, but then you have to source the right plastic. I have tried Nylon and POM (Delrin) and the second seems to do better but not sure what actually is used in high level, high load gear.
For a montain board I wouldnāt care about the sounds and more about the strenght of the gears so spur gears si for sure a plus.
Nice that steel on steel is fine. That would be my option but read that you better run them in oil or they wear out fast. Based on where you read there are different info. A bit confusing
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Is there any type of grease recommended for metal on metal gears? Iām using standard white lithium and itās getting a bit toasty 
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what gear to you have steel on steel. Not may out there except Trampa I think.
I would think you need an high temp, high load grease. Pretty dense that softs when temperature rises , but I ma not a grease expert.
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Using the spiral bevel gear drive
noticing the gearbox getting hotter than my motorsā¦ definitely have to get something heavier I think
yeah thats true. Time will show
for grease ive just took normal longtime grease, seems to work fine but there is something better for sure.
Oil would be crazy but I dont see any way to get this working 100% right for the emtb so we just have to test with grease
I will keep you updated how it goes
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I saw Stefanās videon awesome project dude! Cool that someone is testing some proper steel on steel gears. Do you have a link to the stock gears you bought? Stefan mentions they are commercially available.
Theoretically helical gears are stronger than straight when all other parameters are the same.
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iam not sure here. From what I know straight is a bit more stronger. Racecars also use straight because of that reason. But iam not 100% sure. For esk8 helical is strong enough for sure 
@Creavenger I was checking the supplier site but I cant find the EXACT gear anymore. I will check for that later!
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There are various parameters when designing a gearbox such as axial thrust etc.
We simplify by saying this is stronger than that etc.
When talking gears we essentially make 2 different calculations/checks gear/pinion bending and gear/pinion wear.
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For sure spur gear is stronger than helical but in race car they use it because of cost. They replace it every few competitions so reason to complicate life with helical. Otherwise they will be fine as well
Do you mean the other way around?