Geometry of Road Bikes

"Hi, this is Aaron Phillips for Expert Village and this is choosing the right bike for you. Typical wheels have thirty-two spokes, this one has fewer and this is factory built wheel, in this case it is built by Shemano. There are a lot of other models out there that are much much nicer, but the basic concept here is to thread the wheel with fewer spokes and thread those spokes a lot tighter and make that wheel stronger, more rigid and more responsive and lighter and faster. You have got a braking surface here that in many cases is ceramic that allows you a little bit more braking power. Like I said road bikes have just a very kind of tight compact geometry. In fact the geometry has changed a lot in the last probably eight to ten years. Road bikes now have what is called almost all have compact geometry which makes this front triangle lower to the ground, gets the rider kind of sitting up off, gets the ride more aerodynamic, makes the bike lighter, more responsive and just makes it more of a racing machine. On a road bike, you have really really tall gears. By tall gears what I mean is just gearing that allow you to pedal through about forty, forty miles an hour. You have got fifty-two tooth frame ring, it is a massive gear, it is like if your fifth gear on your car if you have a manual transmission or your high gear for freeway cruising. It is a really big gear, a couple with a small eleven tooth cassette in the rear, allows you like I said it will pedal right through forty miles an hour and up. The pedals on a road bike, these are road specific pedals, unlike mountain bike pedals they only clip in on one side rather than both sides. Presumably on a road bike, you are dealing with less intense to rain and you are able to clip in kind of like you are rolling along without a lot of resistance as you are rolling along on the road. The tires on a road bike are very slender you might say. This tire is seven hundred C which refers to the circumference by twenty-three C which refers to width. This is a racing tire, it allows you to have very little rolling resistance. You run this tire to hundred and twenty five pounds per square inch that allows you roll as fast as possible and you will note that the tires have essentially no thread, it is a racing slick. By contrast the tires on your car, run at about thirty-five pounds per square inch and the tires on a mountain bike run between thirty and fifty pounds per square inch, so hundred and twenty-five PSI, you got a lot of pressure in there and you are rolling along really fast with very little rolling resistance."