View Full Version : Free roll forward distance with bearing

2011.04.10, 10:31 PM

I just got the AWD (new orange chassis) and applied the Atomic ball bearing, but I found when I roll the car forward (without power), it still not being rolled smoothly. Rolling distance is about 1-2 ft and I can "feel" the resistance ...

Beside bearing, where should I check the source of resistance? or it is normal

Any help would be appreciated

Thanks !

2011.04.10, 11:49 PM
It really shouldn't roll much with motor gears attached. Ball diffs create some resistance as they should.

2011.04.11, 06:35 AM
The motor needs to have little drag brake to have roll in Awd.

2011.04.11, 09:46 AM
In general, you want your car to have as much roll as possible without having the motor in. If it doesnt roll, then there is something binding in the drivetrain. Different motors have different drag brake effect, and it is important to find the type of motor that you need for the power level and drag brake effect that you are looking for. Gearing plays a big part in this as well. A higher gear ratio will slow the car down more, give you more acceleration and less top speed. A lower gear ratio will give you more roll, less acceleration and more top speed... If the motor has little drag, and the drivetrain is free, and you have very little roll on the car, you could have a tight gear mesh... different companies gears have different effect. I find the best mesh with the Kyosho plastic pinions and spurs, however, if you run a hot motor, the pinion can melt off...

2011.04.11, 10:10 PM
Thanks for all the advice !

My AWD are all stock, only applied Atomic bearing.

I will play with difference gear ratio to see the effect on rolling distance