I don’t actually use any extensions myself, but
@Garcbomber brought up a good point about the pins falling out when the wheel isn’t there to hold it in place on extensions. I stand corrected, I do have extensions on an ERevo, Redcat branded, and cheap too BTW. I think they offer +5 and +10mm, for the Kaiju. Anywho I had issues with the pins falling out since the wheel doesn’t reach the pin to “block” it in.
I used a cut off wheel in a die grinder to cut a groove into the corners of the hex inline with the pin slot, used o rings to trap the pin in place. It works well, but rubber o rings are vulnerable. I suppose a wrap of mechanics wire or similar might hold up better, though the o rings have held for me to date.
I originally bought the extensions to use on my Kaiju, +10mm. The Kaiju and the Erevo are quite narrow compared to say a K6 or Kagama. I had to take them back off the Kaiju after I bent my third stub axle. Kaiju stub axles are weak, they have a section where they “neck down” in diameter between the 2 axle bearings, terrible design. Almost seems intentional. The Erevo axles have no void, nor any other brand I’ve ever seen.
Here are the Kaiju stub axles, always bend right where they neck down..
