Mounted combat rules?

[BroccoliRage]

I created an NPC for my games with my daughter, a wirey, nerdy little engineer guy named Pjotr. He's a total glass cannon. He can clear rooms with his steampunk-esque weapons like flame thrower or a cranked mini gun created from a captured Skaven weapon, but he cannot soak up damage.

Anyway, he's created a covered wagon with a mounted repeating crossbow. After rescuing Sir Rognar, the party - aka The Last Ones Standing, Inc. - have been contacted for another rescue. I am working out the details of how to run a chase after leaving the dungeon, where the party fends off Orks riding bears and wolves.

I'm wondering if anyone has worked out rules for moving/mounted combat here. It seems if I were to find that anywhere, it would be here. I ran a search and didn't find anything, so I'm making post.

What do you guys think? Need more info, ask and I'll reply.