Mountain Biking - Cannondale Bad Boy

I was checking out the Cannondale Bad Boy Ultra, cause I want a bike to take on the rural stretches of Honolulu, as well as get to school and the shops. Just change out the wheels for some nobbies. But I saw the super low derailer, and wondered, won't that be a problem? Don't off road much, but wouldn't that thing get ripped?

The SRAM X.7 is pretty standard for a MTB.

i was looking at that bike sometime ago in the store. I like it a lot, pretty expensive for a commuter/stretcher ;), but if you got the dough, go for it.
Here's a link with reviews in case you feel like reading: http://www.roadbikereview.com/2002,Cruiser,Bike/Cannondale/PRD_101214_4226crx.aspx

Its in the same place its going to be on any other bike.

The rear end is no lower than any other derailleur that I've seen, to be honest. I don't think you really have anything to worry about. But doesn't it have 700c wheels? I know you can buy 700c knobbies, but I dunno that that frame can take much over a 700x38c. Most commuter/road bikes don't seem to. It may be different, though.

The Bad Boy is basically a mtn frame with disc brakes with a set of 700c rims laced to disc hubs.

You can convert ANY disc mtn bike to a bike with a similar set-up.

I'd suggest getting a mtn bike with standard 26" wheels for off-road use and then get a set of 700c rims built up and swap out the wheels when you want to hit the pavement.

Much cheaper than buying a second bike!

Actually if $$$ is a concern, you can buy a set of 26" slicks and mount them on your standard rims. I've seen slicks as thin as 1" (about 25 mm) with pressures up to 110 psi.

I'd stick to 1.25" tires though as the 1" may be too thin for the standard rims.