I'm 16, and I'm 5'7" 170lbs. I'm definitely out of shape right now. I've started getting back in shape by cycling, and I'm taking weight training at school. I've bought a few things to improve my ride: gotten slicks for my mtb, got a cyclocomputer, and got some bike shorts. The bike I ride is technically my dad's, but I'm the only one who puts any miles on it. It's a pacific mtb, and I don't know much about it. It's a 21sp with trigger shifts, has v-brakes, and it has shimano components (likely low-end). It's a pretty low end bike, and I was wondering if I would benefit from buying a new one. I'm interested in hybrids because they seem to fit my use well. I only ride on the road, but the area around me requires a fair amount of hills. I've also seen that hybrids aren't that great, and that a mtb with slicks (similar to what I have, but presumably a higher quality bike) would do just as good, if not better. I am looking at a budget of under 500 for the bike alone. Any help is greatly appreciated.