Mechanical brake / Castle Neu problem

[starscream]

From your picture, it looks like you could go with a smaller brake disc. The smallest disc I know if is the Losi 8ight rear brake disc. A smaller diameter disc my give you the extra 3mm you need.

A smaller diameter brake disk wouldn't help would it? What would be more helpful would be either thinner brake pads? Then the motor would fit "over" the top of the end of the screw that holds the brake pads together, which you can see is touching the front of the motor, and hindering it from moving any further toward the spur.