In late January I bought a Diamondback Topanga mountain bike. When I got it I was not sure what kind of riding I would be doing so I got a mountain bike to be safe. Since getting my bike I've done only paved trail riding and a ton of it. I feel like my knobby treads and heavy bike may be slowing me down and probably isn't exactly fit for 20-30 mile rides. I was wondering if it would be better to buy a road bike or just get some slick treads. Slick treads would be a lot cheaper but I still have the heavy frame problem. My friend knows of a guy who builds bike for around $400 when you trade in an old bike. I have two bikes to trade in (not my topanga) so it might be closer to $250. This wouldn't be a high end bike but still its a road bike for $300ish. I would obviously prefer the road bike but I'm 13 and I would have to do a lot to try to convince my parents to let me get it. I was wondering if I should stick with what I have now, pay for slick treads, or get a road bike. Any advice is appreciated.