Thorp Dirt Burners Losi JRX2 LRM Gears

[BattleTrak]

You don’t see much info out there about these…This is from my collection for reference.

Thorp hard anodized aluminum gears.

Early parts:
#5101 left gear
#5102 right gear
#5103 Diff gear





Later they came out with a center bearing diff gear, which Losi also did with it’s plastic gears. Unlike Losi that used two special 7/64” wide bearings, Thorp uses two of the standard 1/8” wide bearings. The #5108 right side gear is machined slightly deeper than the #5102 right side gear to accommodate the two bearings.

Center bearing diff parts:
#5101 left gear
#5108 right gear
#5107 Diff gear







Top gear and side gears are made from Delrin. Notice the side gears have been hollowed out/lightened..like the Losi low friction gear set.







More info: https://www.rc10talk.com/viewtopic.php?f=27&t=39934

[scoobyrs25]

I have that setup in my original car. I was able to find one side on ebay for building another, but not the other.

[ChocoTaco73]

Cool stuff but never understood the need, unless someone was running insane power on a high-bite track. Even though there weren't any way back when.

[BattleTrak]

Cool stuff but never understood the need, unless someone was running insane power on a high-bite track. Even though there weren't any way back when.

I think the melted diffs were just a result of poor maintenance and lack of keeping up on the adjustment. Yeah, these immediately defeat the Low Rotating Mass notion but are also very cool because of how nicely machined and smooth they are!

[BattleTrak]

The Thorp Delrin top shaft gear also fits properly on the Losi A-3120 Hydra-Drive/Slipper shaft. Which means it will also fit the A-3007 JRX-Pro top shaft and the A&L Power Clutch shaft.

[orangemazda]

I was one of those dummies who thought the diff in the Jrx2 was a slipper and melted the stock gears. I ran this Thorp set which allowed me to continue my dummy ways! As a young teen, I didn’t know any better.

Cool stuff but never understood the need, unless someone was running insane power on a high-bite track. Even though there weren't any way back when.

[BattleTrak]

Thorp gearbox with Losi slipper completed and installed.

[RogueIV]

These aren't immune being neglected or treated as a slipper. This is out of my old LXT. Not sure how long this was abused for but it's got a pretty deep groove in it.

[jwscab]

Those stock diff gears no matter how well maintained can get melted with low turn motors without a slipper.

[Chewbacca]

Those aluminum gears are nice.

What got me into higher grade RC buggies was when my younger brother bought a used Losi Jrx Pro SE. I then bought a used RC10T i think. That was the time when the Losi XX and the RC10 B2 and T2 had already been released.

Then when old RC stuff was still dirt cheap on eBay, early 2000s I guess, I also bought a JRX T (maybe a junior T) to accompany the buggy.

I don't know if I was tightening the diff too much, but I managed to crack two diff (LRM) rings, and was fed up and sold the Truck again.

If I remember correctly the hexes on my diff gears were just slightly too large for the hex holes in the diff rings.

Anyway that was my experience with the LRM Diff. I found the xx / Pro SE transmission to be way superior.

[aconsola]

I've gotta find that 5108 to fill in my collection.

Does anyone know what 5109 or 5111 are? (assuming they weren't skipped)

The 5110 complete set has a ball bearing center gear and the deeper recess side gear as well, didn't know it was available separately though.

5100 Diff gear set
5101 left gear
5102 right gear
5103 Diff gear
5104 Top gear (delrin)
5105 Top Shaft
5106 Gear and Shaft Set
5107 Diff gear (bearing style(
5108 right gear (for Bearing style center gear)
5109 ??
5110 Transmission set 5 piece (ball bearing center gear)
5111 ??
5112 Out Drive Gears

[aconsola]

A thorp diff gear vs brass top gear, nice and pointy at the tooth tips. There was a ton of brass dust in the gearbox when I received it, probably could have run a couple more packs before it fully let go.

Still fared better than some of the plastic gears have

[BattleTrak]

Nice collection @aconsola! I have never seen the sets..thanks for posting that pic. I’m not sure what those missing numbers are either. I will guess they are another combination of parts..like maybe all the Delrin gears in a set.

[ChocoTaco73]

Funny, I picked up a JRX buggy for parts and was pleasantly surprised to see Thorp gears and MIP diff rings. I went ahead and picked up a non-slipper topshaft and output gears for my shelf queen.

[Nige55]

The Thorp Delrin top shaft gear also fits properly on the Losi A-3120 Hydra-Drive/Slipper shaft. Which means it will also fit the A-3007 JRX-Pro top shaft and the A&L Power Clutch shaft.

I've just done this exactly after I received the topshaft and delrin gear today. However it binds when I tighten the gearbox fully. Did you need to grind any gearbox inner? I notice my Thorp gear is marginally wider than the stock gear for that topshaft.