Until today I've been doing 200km brevets on a trekking bike. It was quite comfortable, there was no ass pain after that, but the average speed was low (24km/h). Also if the wind blew, I had problems riding further, or arms were aching from taking more aerodynamic position.

So I bought a road bike, and it's great, but after doing 50km on it:

• ass pain became unbearable (I had pants with a gel diaper)
• my back and shoulders were aching from road bike position

Is road bike really a good choice for 200km brevets or longer?