Hey Matt,
After looking at the posts and thinking about what you wanted in a firearm and what you were going to use it for, and considering you are on a bike.
If I were you, I'd just get a nice airweight .357 Mag. five shot with some nice standard hollow points. Even more likely just a .38 spl with some +P rounds. With an airweight it's gonna buck a bit especially with the .357's but in a situation with an animal you're gonna be right close in all probability. Although the .357 would be marginal against an adult Griz or Black bear it would certainly stop a charge in short order especially if you are able to do a head shot. Awful difficult to keep your cool in an attack situation especially if you are in a tent but having the weapon right at hand, under your pillow so to speak, would likely be the best scenario.
If you're wiggling like a fishin worm on a hook in the jaws of a nasty old Griz, any rounds you can get in him are gonna change the situation but it ain't gonna be fun.
The airweights are nice, small, light weight and perfect for a CC on a bike.
More food for thought!
B