[beerobber]

Thank you, thank you for that! I spent half an hour this morning trying different setups in the JVN mechanical design spreadsheet and had realized that the 8-inch wheels needed a higher ratio than the Toughbox Mini. The single-speed gearbox you mentioned comes with a hex shaft that is the correct length for the chassis we have, and I was just wondering if the 60:14 gear set was the right one. I'm going to give it a go.