Most of the latest research shows that – for a given type of tire – the wider tire has slightly better (lower) rolling resistance. Not all tires are created equal in this regard. It is the amount of energy that the tire ‘uses up’ as the casing contacts the pavement and deforms, and then returns to its normal shape as it leaves the pavement. This does not mean that it’s the coefficient of friction between the tread and the asphalt. In simple terms, rolling resistance is the amount of power loss caused by your tire as it rolls down the road. Narrower tires must be ridden at higher pressure. If you use the same pressure on a 23 and 25mm tire, the 25mm tire has 2mm more distance that must be compressed before the tube will pinch. Wider tires allow you to use a lower pressure with less risk of pinch flatting compared to narrower tires. If you go too low, however, you can bottom out the rim on bumpy roads, causing a ‘pinch flat’ to your inner tube. Lower pressure lowers the spring rate of the tire, making it more comfortable. What we need to understand, however, is that pressure is necessarily related to this ride comfort. This tends to mean that the ride is smoother. If you have more tire underneath you, you’re effectively riding on a larger pillow of air. If the tire is a lot wider than the rim, the brake cannot open enough to let the tire through, forcing you to make a more difficult adjustment (e.g.

If the rim and tire are of similar width, the brake will open sufficiently to allow the tire to pass through. This lever can only open the brake a certain amount. Most standard caliper brakes have a small quick release handle to easily spread the pads apart for wheel removal: The other reason that your rim and tire width should correlate is that it affects how easily you can remove the wheel/tire from the bike. The two pieces put together make a relatively smooth shape, compared to a very wide tire on a narrow rim (which tends to look like a lightbulb). There is less aerodynamic penalty with a wide tire when you use it with a rim that is also wide. Put simply, the width of the tire and rim should roughly correlate. There is something else to consider aside from just your tire width, however – the width of the rim on which it is mounted. There is less tire for the wind to ‘see’. It is those other consequences of the weight that are deal-breakers.Īs we can all expect, narrower tires tend to be more aerodynamic. Most of those very thick tires also have a stiff casing, which tends to be higher in rolling resistance and have a harsher ride quality.

For racing, I would not buy a super heavy tire, but not because it is heavy. With tires, I tend not to worry about buying the absolute lightest tire – the attributes of aerodynamics, puncture resistance, and rolling resistance are all more important to me (and there are so many other places to save weight on a bike). If your bike weighs less, there is less weight to carry around… so it’s easier to pedal up hills. Let’s hit each of these key considerations one-by-one. Tire width generally does not have any blanket effect on its puncture resistance. they roll slightly faster over the pavement). Wider tires tend to be more comfortable and have lower rolling resistance (e.g. The general tradeoff to consider is this: Narrower tires tend to be lighter weight and more aerodynamic. Why might you pick a different width of tire? That’s the ‘standard’ today, so chances are your bike has this exact setup. Let’s pretend that you have a triathlon bike with 700c wheels and 23mm wide tires (e.g. In addition, if you tried to mount a small 650c tire on a large 700c wheel, you couldn’t physically mate the two they just wouldn’t fit. If, for example, you tried to put a small diameter 650c wheel and tire on a bike built for 700c wheels and tires, the brake pads would not physically touch the wheel… so you couldn’t stop the bike. Note that you must always use the same diameter of wheel that came with your bike. 700c is typically used on larger bikes, and 650c is used on smaller bikes. When it comes to diameter, there are far fewer options for road and triathlon bikes compared to the options in width. On a cyclocross bike or 29-inch mountain bike, you could see tires as wide as 700x35c or 700x58c. 23mm wide tires have been the standard for most road cycling over the past couple decades. On a ‘700c’ wheel, you can have a range of different widths. For the long explanation of these numbers, take a look at the story linked at the bottom of this page - Wheel Size Wars. 700 refers to the diameter of the tire, and 23 refers to the width (both in millimeters).

Wheel size comparison