Just wanted to share my bad news...

[Unsullied_Spy]

That looks like a material or production problem to me, but in truth a 1/8" shaft is NOT thick enough for a CRT .5. If you have the normal chassis with 2.2 Buggy wheels the 5700 will be OK for now but still rather underpowered. As others have said, get a Medusa motor. Myself and most other E-CRT .5 owners use the 50mm Afterburner v2 rated for 3300KV with the 5mm shaft. You would be hard-pressed to break the shaft on this motor and it has a TON more torque than that Castle motor. The Castle motors are great in 1/10th scale 2wd, touring cars, etc. but CRT .5s need something a little more beefy.