Help with torque caculations

I need some help with figuring out the maximum payload for a robot I’m designing.

I'm looking in to using either the Wild thumper 4wd (https://www.robotshop.com/letsmakerobots/node/14156) or the Rover 5 4 motor version (https://www.robotshop.com/letsmakerobots/node/23331)

Both of the data sheets for these robots provide the gear ratio and stalling torque for each motor is it possible using these values to calculate the maximum payload I could use on these platforms?

Rover 5 has a stalling torque of 10Kg/cm and a gear ratio of  86.8:1

Wild thumper has a stalling torque of 4Kg/cm and a gear ratio of 35:1 (or at least the version I’m looking at does)

You need a bit more info

You need a bit more info first.
You already have the torque values, but for each example you’ll also need the chassis weight (everything but the payload) and wheel diameter.

Another parameter you need to consider is the maximum angle you want to be able to climb. If you’re running around the house on flat floors, a few degrees may be acceptable. To climb rocks and hills outside, you’ll have to use a more ambitious value for your angle.