Ok, I just got a road bike and it is really nice about 2k WORTH of bike but the seat is super hard and a little painful. Anyway, I have a mountbike as well.

For some reason i like to ride on my mountaing an road bike up high in a not so efficient manner. I tried this on my road bike an it actually is more relaxing than my in the Drops feel or even in my aero bars look. I mean the other ways are nice but it appears that my best position is sitting more upright. It feels easier on my legs, back an neck. So my question is should I buy a different cheap comfortable bike or convert my mountain bike with smaller tires, clipless pedals.

I Commute 18 miles each way for a 36 to 40 mile commute to work. I was talked into the guy at bike rack into getting a road bike for such distances. Since my seat hurts so much and the position of biking over the last 2 months is not as nice as my Mountain bike an different bikes made for comfort does it seem reasonable to bike that distance with a bike that is made for comfort vs speed. As of now it take me 55 to 120 minutes to get to work. If i bought a folding bike or one that is more upright would it hurt my speed ? Would I be more comfortable to ride it longer distances ?

Thanks jay