I've been having some issues with parking my bike on mud/gravel, so I thought it's a good idea use this as a learning opportunity for FreeCad. My bike is a Bajaj N250, so it's foot dimensions are around 5x4 cm, the STL is exported for those numbers however I've added the FreeCAD file as well. You should be able to change the values in the spreadsheet of the part according to your own bike or if you'd rather have the base thicker or bigger etc.

I've also added a hole to the corner to attach any sort of string to make it easier to get it off the ground and some dents to wrap the said string around the pad.

IMPORTANT NOTE: I'm uploading a slightly smaller version to here because the one I tested had 150x150cm base which turned out to be way larger than I expected, the uploaded version is 120x120 which is probably still good while being more carryable. I did a small test with the big one on the side of the road on gravel and it felt pretty alright, I've given it a few really good shakes and even pushed my own weight onto the bike and didn't notice anything off, however can't say anything about it's prolonged use. Test it yourself and be careful with it I'd say! I have no background in part design!