Originally Posted by
Rolla
A hundred bucks is going to get you a steel or aluminum frame, probably one that is not especially light. ..........
Personally, I'd just buy a frame that fits you well and not worry too much about material or weight. You can find other places in the build to shave a pound.
There's a 2.8 Cannondale M-700 sitting on my local CL for $120 in near-rideable condition (needs tires and some lube). I snagged a vintage KLEIN Pinnacle MTB for an even hundo from a flea market a few weeks back, so they're out there.
HuffyMaster3000 it looks like you're gearing up to spend a pretty good chunk of change to scratch -build a bike that you could probably achieve by starting with a complete bike and adding mods to get it to where you want for a lot less time and money