Reducing Your Drivetrain’s Rotating Weight with Robinson Racing Products Gears

This review is meant to help people that are running spec classes like 13.5 and 17.5 as well as 21.5 turn brushless motors, but this also can help other classes too.

This review can be used for any class of cars you race, but this certainly can help 17.5 or 13.5  spec offroad classes as well as oval. The gears will also work on 1/10th scale sprint cars and 1/10th scale Late Models as well as many other cars and trucks. Please refer to your manual to see if these products will work for you. The classes I race are Short Course based Dirt Modifieds and Late Models. I race an SC1O but many of these products will work on other trucks as well.

The main goal here is to reduce the rotating weight in the drive train and this is done with  the Speedy’s Racing Parts slipper eliminator. The eliminator removes a lot of the excess rotating weight of the slipper, like the pads, the metal disks, spring, nut and the heavier stock gear as well. All these extra parts are just extra rotating mass. By running the eliminator it will help reduce the heat the motor will create, add extra speed, and make changing the spur gear easier. Below in the photos you will see some of these products that will help achieve these results. Robinson Racing Products has some really great gears to help reduce the rotating weight Using the gears along with the Speedy Racing Products eliminator will help reduce even more rotating weight.

Keep in mind this will not allow you to adjust the slipper, since you removed the whole slipper aaaembly. You are basically running the same way as if you tighten your slipper really tight, but you get the benefits of less rotating weight in the process..

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Above you will see the Speedy’s Racing Parts Slipper Eliminator. It is made out of aluminum and weights about as much as the spring that is used on the  actual factory slipper assembly. This means you are already saving the weight of the pads and the nut as well as the metal discs too, not to mention the lighter Robinson Racing Products lighter spur gears.


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Here is a photo of the parts on the magnetic micro mat.  Robinson Racing Products Super Spur Gear and aluminum pinion gear, Speedy’s Racing Parts Aluminum SlipperEliminator.


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Above you will see the Robinson racing Spur gear. You will notice the holes in it to make the gear lighter. I also enjoy the fact that it is white and you are able to write the gear size on it. It is too hard for me to see the numbers on the black stock spur gears. It also makes for a faster way to find the gear when you want to make a quick change in between heat races.


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Shown above are the pinion gears. Robinson Racing has a choice of the lighter weight aluminum (black) pinion gear for those spec racing classes. Or choose the steel (silver) pinion gears for the open lower turn motor classes. They are stamped with the tooth size on them… The magnetic mat works great stopping those tiny set screws from rolling away and falling on the floor and getting lost.


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Another photo of the Aluminum pro pinion gear in the package.

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Another photo of the steal pinion gear in the package.

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Above is the super Spur gear as you can see it is stronger with smaller holes and is a little heavier.

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Above, you can see the difference between the 2 different 78 tooth spur gears and it is most noticeable for the extra weight saved by the larger holes. But the gear on the right maybe what you may like for a stronger gear or for the lower turn motors.

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Just some different size gears from Robinson Racing Products.

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This is the best photo to see the reduced weight and extra parts that are needed for the slipper assembly.  Also, changing the spur gear  is faster and easier as you don’t have to worry about the slipper pads not being set correctly. The Speedy’s Racing Parts Aluminum Slipper Eliminator weighs as much as the steel slipper spring on the right, You can see the pads,  disks and the gear end up adding  extra rotating weight, if you race in spec racing this is a disadvantage.

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A close look at the difference of the gears and how you can read the sharpie numbers, so much easier and the extra weight reduction comparing the  two the gears.

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It may be hard to tell but if you look at the two gears you can see the Robinson Racing gear on the right is a little thinner, saving a little more weight.  The material of the white gear is stronger than the stock gear on the left. I took the gears and tried to twist them and the the stock gear flexed more than the gear on the right by Robinson Racing.

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Just another photo showing the difference in weight with the eliminator and spring being about the same weight.

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 Shown on a SC10, removal is simple. Remove top nut and slide all parts off. Most people know this but a few new people maybe have not done this yet.

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Always use blue (removable) Loctite when putting in all the screws. The Eliminator has 4 screws. 2 for screwing it down to the top shaft and  2 used for screwing the Spur gear down.

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Above you can see I have screwed the set screw to the top shaft. 2 screws are used, one on each side of the Eliminator.

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Now slide the Robinson Racing Products Spur Gear over the top shaft and press it down making sure you line up the inner holes with the holes on the Eliminator. Don’t forget to use blue Loctite. Also, snug down slowly on each side till tight, but don’t over tighten.

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Second screw is in. Set your gear mesh and place your gear cover on. The combination of the Robinson Racing Spur gear along with the Pro Aluminum pinion gear saves you even more weight. Speedy Racing Parts Slipper Eliminator will save you extra weight and the combination of all three will help against increased motor heat. That weight could be the difference between making the podium, or looking up at the winners. We all know we want to be standing tall in the top three at the  end of the day.

If you are looking for work mats and maintenance products, check out For more information and to see many other products, check these manufacturers and see what else they carry. , and

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One Response to “Reducing Your Drivetrain’s Rotating Weight with Robinson Racing Products Gears”

  1. Wayne says:

    Great Tips on this Paul, I have admit, talking about it was good, but when you add the Pictures to everything it makes it even more clear. It actually makes me want to switch everything over to this set up to eliminate as much rotating weight as possible, to keep my Bullet Motorworks motors running cool.

    Thanks for the education…..Wayne

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