Road Bike Tire Basics
Road bike tires generally have a large diameter, a smooth tread patter, and narrower widths than off road tires. Let's look at the different parts of typical road tires to assist you in finding the right tire for your needs.
Diameters and Rim Sizes
How to interpret the sizing information written on the side of a tire, usually in a format like "700x23c"
- The "700" is a reference to the diameter of the tire
- The "23" is a reference to the width of the tire.
- The "c" is a designation of which 700 rim it uses, there are other letters such as the "700D" tires used on some hybrids in the mid nineties. There are 650c (biathlon and Women's Specific) and 650B (French/Japanese Touring) rims.
- Fractional sizes like "27x1" will not fit the same rim size
- Slick tires marked "26x1.0" are usually mountain bike tires, and will not fit 650c or 650b rims.
Road Tire widths are measured in millimeters. The style and intended use of your tires can help determine the appropriate width for you.
- Use wide tires for training where extra traction, comfort and durability are desirable. Run wide tires at the lowest pressure possible for maximum grip.
- Are typically over 25mm wide and weigh slightly more.
- Can be run at lower pressure, and will provide a larger contact surface to the road.
- Found to be popular with commuters because they; pinch flat less, protect the rim from damage, have lower rolling resistance,and smooth out the bumps on rough roads
- Very wide tires (28mm and wider) may not fit in all frames the tire may rub the frame, the underside of the brake caliper or there may not be any space for an untrue wheel.
- Use narrow tires for road riding, easy trails and fire roads where speed is the goal. Smooth or slick tires roll the fastest.
- Usually weigh less - sub 220g is a light tire
- Can be run at higher pressure, up to 160psi on some models
- Roll faster than wider tires
- 23mm is the most popular size for training and racing
- Very narrow tires (20mm and narrower) will not fit well to wide rims
Threads Per Inch (TPI)
This number represents the threads per inch in the casing of the tire
High Thread Counts
- Use high thread counts for fast riding and racing.
- A TPI of over 100, making a more supple tire.
- Have a thinner sidewall, and usually weigh less.
- Tighter casing is more puncture resistant, and also usually cost more.
- Available in adjustable resistance models.
Low Thread Counts
- Use low thread counts tires for a thick durable tire that is less expensive for training and long miles
- At thicker tire that is usually more resistant to cuts.
- Have a thicker sidewall, and on the heavier side.
- Less than 100 TPI
The edge of the tire casing that contacts the rim. Most tires we sell are "hook bead" tires, with the exception of a few "sew-up" tires.
Kevlar (or folding) beads
- Allows the tire to be lighter and to fold up for easy transport and storage off of the wheel.
- Usually more expensive, and can be harder to mount, especially when the tire is new.
- Use folding bead tires for racing or riding where less weight is important. Folding tires can be handy to keep around in a tool box or race kit in case you damage one on a trip.
- These tires hold their shape even when it is not mounted.
- Slightly heavier.
- Usually the least expensive, and easier to mount when new, but they don't stretch out to become easier later
- Hard to find on good high thread count tires.
- Use wire bead tires for an inexpensive tire that needs to be easy to mount. Wire bead tires make excellent training tires due to their low cost and ease of mounting. If mounting the bicycle to a resistance trainer fit the least expensive tire that comes in that size.
The makeup of the tread will determine how the tire grips to the road.
Carbon Black Compounds
- Use carbon compounds when durability is very important. Each tire maker has their own compound which wears differently, some experimentation may be necessary to find the best one for the purpose.
- Typically take longer to wear, inversely they are not as sticky
- More accepting of abuse like poor storage and resistance trainer use
Silica and other synthetic Compounds
- First, check the packaging to confirm that the tire suits the intended purpose
- Can be engineered to have any desirable attribute
- They don't hold up to trainer use very well due to the heat of friction
Multi Compound Tires
- Multi Compound Tires excel when you need the firm base of a hard tire, but the extra grip of a soft tire. Although more expensive, the balance of durability and performance is justified.
- A hard compound in the center tread with softer compound on the sides for more grip in the corners