I'm doing the day bike ride to conquer cancer from Vancouver to seattle on june 21. I asked for help in picking a bike, and everyone told me not to go to a box store to get a bike, get a GOOD bike.. like a norco, trek, etc. So, I bought a used one on Craigslist (I have a limited budget for this!). I bought a trek 4500. It's a mountain bike. Now, I'm having second thoughts about whether it's suitable for a long distance ride. I rode it for about 20 minutes over the weekend,and my butt is sore! Last eyar on vacation, I rented a hybrid, and I managed to stay on it for 8 hours.

So my question is, can I buy a new seat, maybe some road tires for this bike to make it suitable for a 2 day bike ride? Or should I just sell/trade this for something more suitable? It's a nice bike- it rides really well. But I think I might also prefer sitting more upright, instead of leaning forward.

I'm kicking myself, because I only have 2 months to train for this! Maybe I should ride this more and see if I get used to it. But while picking up oil for my car at canadian tire, they had a cheap $120 bike on display, that seemed much more suitable than this $600 I bought. Thoughts?