I have a Tekin RSX speed control and would like to know if it will work in a Shortcourse Truck in Offroad racing with the tekin motors.

2wd or 4wd? Might make a difference. If 4wd what motor (2 pole or 4 pole)?

4wd Shortcourse with a 4 pole motor.

I don't think it's a good idea. If you read up on the RSX they specify it's not for vehicles over a certain weight. I think you would be much safer running a Tekin RX8 since it's made for heavy duty stuff.

I agree, while the RSX can handle lots of abuse from a 2wd, you're over your head if you're going to try to run a 4 pole motor in a 4wd short course.
If you drop to a 2 pole, you might get away with it, but it'll be high stress on that poor 10th scale speedo.

Ok that's all I needed to know thank you.