About this part
Kimbrough Products 48 Pitch spur gears are molded with black 4/6 Nylon plastic, because black dissipates heat into the air better then any other color - and high temperatures are not good for thermo-setting plastics. This plastic is almost three times tougher and will withstand operating temperatures 75° to 125° higher than plastics used by other R/C car gear manufacturers.
Kimbrough spur gears are full width, because a narrow or profiled plastic gear can deform under load, is weaker and less efficient. This can cause drag in the gear train and waste horsepower. The wider a gear is, the more load it can handle. The only time gear engineers narrow gears, is when there is a space limitation. Kimbrough Racing Products gears run quiet because they have the correct tooth shape and don't have to be narrowed. Choose from a variety of tooth count choices to allow you to fine tune the torque and top speed of your model.
NOTE: The use of full width pinion gears is highly recommended.
Reviews4.1 · 9 reviewsacross all options
Bought this as an affordable and available replacement for my HPI RS4 sport 3 (since HPI now sucks and you can find parts except for ebay). This part is a great replacement to HPI part no. 113705. the only gotcha is that this Kimbrough spur gear only has holes for two of the 4 screws that the 'stock' spur gear uses to connect to the drive shaft rod housing. after screwing in two of the 'stock' screws (to align the drive shaft housing) a simple drill of the other holes allows the other two screws to be connected just fine. I could probably get away with just two screws, but I decided to drill so I could put all four just to be safe. That's a long winded response to say, this is a great product/item. Thumbs up.
Does not fit a mugen mtc3. It does not have 4 holes 90 degrees from each other.
I like them. No warp like bad traxxas spurs. Currently using a 69t in my 13.5 sprint. These gears work well in junction with plastic pinions to create a lighter rotating assembly.
Excellent quality as always! Clean no burrs silky smooth mesh with very little deviation in tooth depths. .
Been having good luck with these gears. I often loose all the teeth after a few races. These are holding up well
Reviewers generally rate the Kimbrough 48P spur gears well, praising smooth mesh, clean tooth finish, and durability in several variants (69T, 75T, 81T, 84T, 87T). One buyer using it as a replacement for an HPI RS4 part found the mounting holes only fit two of four screws, requiring drilling; another reported the spur lined up after drilling using markings on the gear. A fitment problem was also noted for a Mugen MTC3 with the 72T variant, which lacks four holes at 90-degree spacing. One reviewer using a 2 star rating reported missed teeth and flex under drag-racing use, attributing it to the plastic construction. Opinions on long-term durability are mixed.
- + Smooth mesh with clean tooth finish
- + Durable in sprint and stock use
- + Good replacement for HPI RS4 spur
- + Lighter rotating assembly with plastic pinions
- − Mounting holes may need drilling to fit
- − Does not fit Mugen MTC3 (72T)
- − Tooth loss and flex under drag racing
- − Mixed durability reports