bought a cyborg RAT 7 gaming mouse... probably the best mouse ive ever owned IMO (owned some razer's, logitech g5's, g500, etc)

works great (especially the sniper button), except one small detail.

I can set the standard scroll wheel to scroll through weapons... but this mouse also has a second wheel by the thumb... i see no in game option to scroll next and backwards through secondary items (wingsticks, sentrys, healthpacks, etc)

Anyone know a way to remap that?

Good request! I too own the glorious RAT-7 and would like to see this as well. On all of my 3 mouse profiles (Red-blue-purple) I have the second wheel mapped to the left and right arrow keys. I attempted to bind functions in Rage to these two keys but whenever I use the wheel, my selected weapon will fire and that's it. (I've had this problem with a couple other games as well.) I'd love so support for mice like this from id. Or if someone finds a workaround, I'd be pleased to know!

By default the Capslock key allows you to cycle through your quickuse items, you could bind Capslock to your second scroll wheel and be able to cycle through the items that way. It won't get you guys the desired effect you want (scrolling forwards only, no ability to scroll backwards), but might be a useful workaround until someone figures out a better, more permanent fix.