Cheers guys,ill wack a 15 and go from there as I've got 13-18 in the box.gonna deff need some new keys coz then grub screw is thread locked to hell and I can see its gonna be trouble.my old turnigy amp/watt meter I used to choose props for my 3d planes would help as it stores max amp and watts ect.i thought like a plane once moving or unloading both amps/watts would drop and being on a less grippy surface would also do the same,but you say when wheel spinning it actually spikes both amps/watts.lecky is deff the way forward anyhow, I just can't see any big dollar 21 motor beating it.i have had loads of rb,os,nova ect and its ballistic in lecky form also a lot more nimble.