Do lightened pinion/spur gears fail faster?

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joshjosh

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While researching some of the top pinion and spur gear manufacturers, I noticed that most aren’t fully drilled or lightened. I understand that reducing material can impact driving characteristics. Scorched RC offers gears with partial material removal, striking a balance between weight and strength.

My question is: has anyone experienced issues with lightened pinion or spur gears that could have been avoided by sticking to standard, non-lightened options?
 
I had a few with holes drilled in them and the others with just material removed were actually lighter.
In the end it often comes down to the material composition and the hardening process / heat treatments they have been through that will determine their strength.

Best quality seems to remain with trusted sources like Saga, Scorched, and Robinson Racing. I think Castle creations now offers some too.
 
I had a few with holes drilled in them and the others with just material removed were actually lighter.
In the end it often comes down to the material composition and the hardening process / heat treatments they have been through that will determine their strength.

Best quality seems to remain with trusted sources like Saga, Scorched, and Robinson Racing. I think Castle creations now offers some too.
Thank you for the quick reply! I usually run Saga, and they do not have a lightened option. I agree, most lightened gears aren’t that light, but the AGFRC ones are lightened and have material removed from the back side. I’m concerned about endurance with it being hooked to a 5690 on 8S.
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Thank you for the quick reply! I usually run Saga, and they do not have a lightened option. I agree, most lightened gears aren’t that light, but the AGFRC ones are lightened and have material removed from the back side. I’m concerned about endurance with it being hooked to a 5690 on 8S.View attachment 404544
Id be curious to see the comparison against saga or similar. I had one like this from another brand and it was heavier.
 
Id be curious to see the comparison against saga or similar. I had one like this from another brand and it was heavier.
The AGFRC has a few more teeth, but it does appear to be heavier. One pro for the AGFRC is that is uses M4 grub screws instead of M3. Due to this the neck is deeper, and adds to the weight.
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I retract my previous statement. Comparing a closer tooth size, and the Saga is noticeably heavier. It still only has the M3 grub screws as well. I’d have to find ones the same tooth count to say for certain, but I’d bet they’re going to be about the same. I’m a fan of the AGFRC, for sure.
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I retract my previous statement. Comparing a closer tooth size, and the Saga is noticeably heavier. It still only has the M3 grub screws as well. I’d have to find ones the same tooth count to say for certain, but I’d bet they’re going to be about the same. I’m a fan of the AGFRC, for sure.View attachment 404556View attachment 404555

Nice! 10g is around 20% reduction in rotational mass.

Seems like good material:

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Nice! 10g is around 20% reduction in rotational mass.

Seems like good material:

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The 2 teeth make the gear noticeably larger. I imagine they’ll be very close tit he same weight with the same tooth count. The only selling point I see for the AGFRC is the dual M4 grub screw, but with unknown durability.
 
Lighter is always better when it comes to rotational mass in the drivetrain. I have never seen a gear fail in the center it's always the teeth. Keep your mesh set correctly and as long as your not getting some monkey metal from some no name Chinese company I would go with the lightest you can find.
 
Lighter is always better when it comes to rotational mass in the drivetrain. I have never seen a gear fail in the center it's always the teeth. Keep your mesh set correctly and as long as your not getting some monkey metal from some no name Chinese company I would go with the lightest you can find.
Thank you for sharing your firsthand experience—that’s exactly what I was hoping to hear. I couldn’t imagine a gear actually exploding, though I’ve heard of it happening to others. I’m just not sure if those were lightened gears or not. I might experiment with adjusting rotational mass to see how it impacts the driving experience. In RC drifting, many of the rules that apply to regular RC cars don’t hold up. For example, in drifting, people often add rotational mass to maintain smoother drifts. They’ll also add weight higher up to raise the center of gravity, which helps the car hold a drift longer and creates a weight shift effect, allowing for grip changes mid-drift.
 
My experience says the only "breakage" would be with teeth chipping off.
This almost always happens from extreme conditions where the motor's pinion gear is no longer aligned with the spur due to a crash or big air jump...
Sounds good! I’ll stick with the AGFRC gears I have for now and see how they perform. I also wanted to share some drift RC upgrades. Overdose is arguably one of the top manufacturers for drift RCs, and this upgrade is designed to add mass to the spur gear. It even comes with additional arms that can be attached to increase mass and create a gyroscopic effect—but I think I lost them somewhere along the way.
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Interesting. What does the extra rotating mass accomplish in regards to drifting? Wouldn't a gyroscopic effect want to resist changes in motion?
 
Interesting. What does the extra rotating mass accomplish in regards to drifting? Wouldn't a gyroscopic effect want to resist changes in motion?
Exactly—it helps resist body roll and maintains more even traction. The additional rotational mass works similarly to a flywheel. For example, in a race car with a lightweight flywheel, you’ll notice it revs up very quickly, which is ideal for fast rev-matching and quick shifts. However, this can make the car feel twitchy. In drifting, smoothness is key, so one tuning technique to achieve smoother throttle control is to add weight.
 
I retract my previous statement. Comparing a closer tooth size, and the Saga is noticeably heavier. It still only has the M3 grub screws as well. I’d have to find ones the same tooth count to say for certain, but I’d bet they’re going to be about the same. I’m a fan of the AGFRC, for sure.View attachment 404556View attachment 404555
It’s official, the AGFRC is lighter. The 42t Saga weighs 50g’s, the larger 45t AGFRC comes in under 47g
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