XRAY - Model racing cars

Hi Teamgp,

I have a question. What's the differnt between 85/17=5 and 90/18=5 gearing by 3.0mm chassis. Is there any advantage for my motor or .....


bye,
Taner (Istanbul/Türkiye)

The biggest difference will be in weight distribution. The larger spur/pinion combo will move the motor forward in the chassis. I haven't tested this myself, but in theory it would provide less rear grip and maybe a tad more steering.

The smaller combo will have less rotating mass for faster acceleration. But the difference will probably be too small to notice.

I would suggest using the larger combo for finer ratio changes to better dial in gearing at the track. I currently use a 120t/64p spur (same as 90t/48p) with a 2.5mm chassis on carpet, even though it sticks out the bottom slightly, and I will probably switch to a 124t with a 3.0mm chassis for even finer ratio adjustments.