Road bike and mountain bike(can help me to solve these two questions)?

1.Road bike-is it sutable for rough surface or flat surface or both?

2.mountain bike-is it sutable for rough surface or flat surface or both?

it is best to use the right bike for what you are doing. you can adapt a road bike to work with rough trails. it is called cyclocross. you can also take a mountain bike and adapt it for the road with city tires and bar ends or something for a better position, but why? at best doing either is a trade off. no matter what you do the road bike is not at its best off road, and the mountain bike isnt at its best on the road. i think most cyclist own at least one of each.

Road bike is not really designed for the rough terrain of trails etc. The mountain bike is more suited to trails and rough terrain but it can handle the road as well. If I were going to buy one it would be the mountain bike.

If you are going to buy just one, buy the mountain bike. I adapted a front-suspension mountain bike for road riding because I got tired of toasting road bikes' skinny rims on potholes. I threw away the smallest chainring, making the original middle chainring into the little one and the original big chainring into the middle one. Then I added a 55-tooth chainring for the biggest one. I put smooth tires on it, and because of the gearing I can keep up with the cars on city streets. And I haven't toasted one rim due to a pothole yet. I used to have a cyclocross bike, but I like this one MUCH better. And it works on the mountain trails just fine, if I put on knobby tires.

Mountain bikes can handle any surface.

Road bikes are more delicate, but they can take some light offroading if you are careful. A cyclocross bike is more suited for road and off road if you are mainly riding on road.

As others have stated, road bikes are best suited for paved roads. A mountain bike is best suited for off-road usage.

The narrow, high pressure tires on a road bike provide the least rolling resistance on paved surfaces. However, they will provide little to no shock absorption for off road usage. Thus, they will tend to transmit every bump into your body. Furthermore, the tire's smooth tread will make for sketchy handling on non-paved surfaces.

On the other hand, knobby, high volume tires of a mountain bike give great traction and shock absorption for off road riding. On pavement, though, their much higher rolling resistance will really cut your speed. Also, a mountain bike's suspension makes for a comfortable off road ride, but is far less efficient on a paved surface.

If you do a lot of road riding with a mountain bike, it is best to put on narrow, slick, high pressure, "city tires." Furthermore, if your suspension has a lock-out, use it.

Hope this helps.

It isn't an either/or. Racing Bikes are not built for going off-road, but Lance Armstrong took his off-road during the Tour de France to avoid an accident and still won. Mountain bikes have shocks and knobby tires for making a downhill decent manageable, but can work for commuting trips too.

So the question to ask is, if you only bought one bike, what's the best bike to handle the most of riding you want to do?

For a starter bike, I would suggest something with an upright geometry, tires that have traction for dirt and gravel, and places to attach bags and racks. The bike that does this for me is an early mountain bike that is light but doesn't have all the equipment later "serious" mountain bikes were built for. I've done several hundred miles of commuting and weekend rides on it and it's been great for me.

Road bikes are very limited in their application; you will be stuck on smooth pavement. Mountain Bikes are extremely versatile, and work just fine on long stretches of road if you put on slick tires. I rode a full-suspension Gary Fisher from Minneapolis to San Francisco and it handled beautifully. If I had chosen a road bike, I'm sure I would have ran into problems because many stretches of rural highway are poorly maintained and riddled with potholes. Plus I probably would have gotten way more flats.

Buy this man a hybrid or cross bike.

I suggested he buy one of each road and mountain bike in the last question, but he must not want 2 bikes. That is hard to understand -- not wanting 2 bikes.