TT01 max spur is 61T. So if you have the largest spur, the max pinion would be 22T. With 58T spur you can use 25T pinion. With 55T spur you can use 28T pinion.
In this example, out of the box it is 61T, and we changed it to 55T. Pinion stays at 25. Stock 540 silver can. Mild speed improvement over 61T + 23T. Seems like upgrading to brushless can give more.
No doubt you can use a 29T pinion, and that should make quite a difference, but then the motor will get overheated very easily….
Depending on the make of the pinion (assuming it is not Tamiya), you may need to remove some plastic from the gear housing to accomodate it.
If the pinion is still scratching on something, try to relax this screw a little bit:
Based on our experience, for brushed motor the 55T + 25T combination seems to have the best balance between speed, power consumption and heat. Under such gearing arrangement, a 19T brushed motor seems to be the most appropriate.
Brushless system can sustain heavier load and you may try 28T or 29T pinion on it.
