RRR - is super light weight can't argue much on that.
My FW05R weight reduction are -
1. Rear kawahara graphite stay
2. Titanium pivot
3. AAA battery size
4. Light weight engine head sink
4. Light engine mounting
5. Light Kawahara centax clutch
1. Carbon composite Arm front and rear
2. Change the throttle digital servor (steel) to plastic super servo.
To much afford on FW to get it slim.. I better go for V1RRR instead