Brushless Rota's

[Mossy]

Does anyone have a definitive explanation of what effect different size rota's have on the pickup/top end in a brushless motor. I have some different sizes to try but need to know the effects of usin 12/13/13.5 mm etc. Mr Sleigh has explained this to me, along with Chris Yardy, but my memory is pretty vague.

Ta

Si

[jimmy]

I'm sure they gave you a really intelligent and clever answer - but from what I can see it's just less torque since there is less leverage on the rotor because of the smaller diameter magnet - like using a shorter or longer spanner. I assume they rev a little higher too.
I only have the big sintered rotor for my nosram motors - and it's too powerful for lil old me.

[DCM]

Larger diameter (or more importantly, less air gap) = torque
Smaller Diameter (bigger air-gap) = RPM

[Chris Doughty]

smaller diam rotor = less bottom end and more rpm - very free running off-power, weaker brakes(but you have to gear it lower)

large diam rotor = more torque, less rpm + much more drag brake, killer brakes! (so you gear it higher)

if you changed rotor without changing gearing the change would be pretty massive, but the change in gearing normally makes the change less noticeable

I think the main thing is the amount of bottom end rip you get with a big rotor and the amount of brakes both drag and pull back brakes with a big rotor, some like it, some don't

[Mossy]

Im lookin to get the best for 2wd. I know i ran the same as you at Oz Chris, but gotta get the balance right in the Speed Passion ones now!

[Chris Doughty]

I prefer small diam rotor in 2WD, I actually really liked the bonded rotors in 2WD, but its all sintered now so I choose the one with the weakest magnets (12.5mm)

[DCM]

worth remembering, with the larger diameter and the taller gearing, you will get things a tad hotter too, but in the end, the aim isn't to make the car quicker, but to change how the power comes in....