Lance Armstrong helped to make the road bike a common item . Speed more than comfort are where these bikes are at their best. The positioning of the handlebars makes the rider's profile aerodynamic. This position also allows for the greatest use of the power source namely the riders legs. The bike has no suspension and rides along on concrete or asphalt. The tire is super thin and under great pressure and it is the only thing that separates the rider from the hard and rough riding surface.
Research, development, construction and design are only a part of the success of a road bike. The rubber may very well be the most important part of the tire. It is manufactured for the proper texture, firmness and consistency. Starting with the rubber helps ensure the best product for the rider.
Dual construction of the road bike tire means an inner and an outer layer. Nylon-fibers make up the inner layer and are counted as threads per square inch or TSI. The more TSI count the lighter the tire but the higher the cost.
The outer layer covers the tire and is slick. That is it has no tread. Tread increases rolling resistance and this will slow the speed. When the race is on concrete or pavement, tread is not needed. In fact it is a detriment by reducing speed.
Road bike tires are available in what is known as clinchers and tubular. Basically clinchers have both a tube and a tire and tubulars do not. How they adhere to the rim is also different. There is also a choice on valves, Presta versus Schrader. Likewise both have advantages which will be discussed at another time.
Now a quick mention of tubular tires since they are used most often by professional riders in races. The tire is lighter and adheres to the rim with glue. Generally speaking the flats are quicker to change and may lose air more slowly allowing for a controlled stop.
No matter which style you choose these tires come in the standard sizes for your bike. The sizes are metric sizes with the diameter equaling 700mm. Some companies still make 27 inch tires to use on older models although your favorite tire, the one you have used for years may be difficult to obtain. You may opt for a smaller diameter tire on your front wheel to help with aerodynamics. Those are also available. The most common width for road bike tires is 23, 25 and 28 mm with 28 being the most frequently ordered .
Getting a flat is no fun, it takes away from your primary purpose and that is riding. It may leave you stranded miles from help. To prevent this you can use liners, puncture resistant tires, a sealant or some sort of foam insulation. For those riding with a chase vehicle this is not a concern. However for the weekend rider one of the above options may be well worth some research .
There are an abundance of bike supply sites online to make it easier to find just what you are looking for in bike tires. Not all of these sites may be the right site for your needs. The best sites are run by professional riders or those with the experience that you need to help you find the right supplies. It won't be easy to buy a tire online, ride it for a day only to find it doesn't meet your needs and then try to return it.