Jeff Grigg from Manchester, MO on 5/24/2007 10:26:24 PM:
"Mountain" or any bike with relatively wider tires and an upright riding posture. The Katy trail is fine packed gravel; very narrow tires are generally OK, but sink slightly into the trail should it rain, which can be frustrating. The very low gearing of a true mountain bike isn't needed, as the Katy trail is very flat. Just about any reasonable bike will do fine.