Three years one rebuild, still the smoothest drives I have ridden.
Stormcore is maxed out to get decent torque on 2:1 (173kv)
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Your pic shows well of how small the gearbox is with the 107s.
@moav That looks awesome! Wth is your top speed with the bergs?!
I never dared to hook up my bergs with the drivetrain, how is the torque with that also?
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Does anyone have pics of the insides of their drives?
I wonder how much efficiency loss there is compared to other gear drive systems.
Gear Efficiency Comparison Table
| Type | Normal Ratio Range | Efficiency Range |
|---|---|---|
| Spur | 1:1 to 6:1 | 94-98% |
| Straight Bevel | 3:2 to 5:1 | 93-97% |
| Spiral Bevel | 3:2 to 4:1 | 95-99% |
| Worm | 5:1 to 75:1 | 50-90% |
| Hypoid | 10:1 to 200:1 | 80-95% |
| Helical | 3:2 to 10:1 | 94-98% |
| Cycloid | 10:1 to 100:1 | 75% to 85% |
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Does it make any note as to directionality on spiral bevel?
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i didn’t see any info regarding that, but technically they are the same if not very similar efficiency?
since its just like helical, but two axles are at 90 degree
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I’ve heard somewhere that spiral bevel gears are significantly worse in one direction than the other
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Well good thing you aren’t riding in reverse all the time then right
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I’ve never tried to go past 45kh because I don’t have protection. It should go over 60. Without a rider, battery full, app claims 72kh.
Overall torque-speed ratio is pro speed. Gear is 1:2 and I’m on 170kv motors with 6" rubber. Tourqe is just fine but I could have better efficiency if I go lower kv cause I don’t come near top speed.
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Bingo!
Usually, they are set up in the direction so that the concave part of the pinion interfaces with the convex part of the other gear. If you do it backwards, you reduce room for backlash.
Depending on drive design, that may or may not be desirable. Zero backlash is never desirable.
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I’m getting the impression there may be some potential in a spiral gear drive.
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I don’t think that’s really true. since the gears are not mirrored, one of the pairs of gears will always be spinning in “reverse” regardless of direction being traveled.
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I’m really curious to see someone do a comparison of motor left right current with these and show the wear after so many miles
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Hmm that’s fair I assumed they were mirrored.
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yeah thats fair. looks like they’re not, which makes sense to help meet moqs for reasonable pricing
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I would really hope/assume they took that into account and have one drive mirrored, but who knows. Maybe going forward if someone (@fujio001 
) comes out with some MAD rocket booster drives, that would be corrected and taken care of
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There you go, they can be called “booster drives”!
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Definitely!
@Venom121212 is correct. Except the the convex of the pinion pushes against the concave of the gear. There is a bevel gear that is similar to the spiral, called a zerol. It has the benefits of the spiral, but can effectively rotate in reverse as well.
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