This post compares the advantages and disadvantages of 25mm and 23mm tires.
The next table compares the weight of 700×23 and 700×25 tires:
|Continental Grand Prix 5000
|Continental Grand Prix 500
|Vittoria Corsa G2.0
|Continental UltraSport 3
|Continental Sprinter GatorSkin
|Continental Sonderklasse II Track
|Schwalbe Pro One Tube
|Michelin Power Cup Competition Line
|Vittoria Rubino Pro
|Schwalbe One TLE
|Michelin Dynamic Sport Access Line
|Veloflex Corsa EVO Folding Tire
|Veloflex ProTour RACE
|Schwalbe Pro One Evolution
|Michelin Lithion 2 V3
|Challenge Strada Pro TLR
Conclusion: The average weight of 23mm and 25mm tires is very close. 23mm are slightly lighter (depending on the models), but the difference is measured in 15-20grams per 1 wheel.
Those grams matter only if one is trying to set a record for the lightest possible bike. If that’s the goal, one can go with even narrower tires such as 21mm.
Air Pressure Comparison
|Continental Grand Prix 5000
|Continental Grand Prix 5000
|Grand Sport Race
|Grand Sport Race
Conclusion: The maximum air pressure is the same (120 PSI), but the minimum air pressure is slightly higher (110 vs 90) in the case of 23mm tires. This is expected since narrower tires need higher air pressure to protect the inner tube from punctures and the rim from deformation.
As a result of the higher air pressure and the narrower profile, 23mm tires offer a harsher/firmer ride.
23mm tires are narrower and thus do not protrude outside of the rim. This profile makes them more aerodynamic than 25mm models. The reduced drag, however, is too small to make a perceivable difference in the world of recreational cycling.
There are other factors (frame geometry, body position…etc.) that have a much greater influence than a couple of millimeters sticking outside of the rim.
23mm tires are very narrow and thus can be installed on pretty much any road frame. Therefore, when it comes to clearance, they win. That said, 25mm models are also sufficiently narrow to put them on very aggressive frames too. Thus, it’s questionable whether this advantage of 23mm tires is that important in this particular comparison.
When it comes to rolling resistance, the following rules apply:
When the air pressure and the tire tread are the same, wider tires have a lower rolling resistance because they deform less and their shape is closer to a perfect circle. In this case, 25mm tires are the winner.
That said, in practice, 23mm tires could run at slightly higher air pressure and match the rolling resistance of 25mm tires.
Side note: The tread of the tire should correspond to the terrain. Slick tires are for paved roads because they provide a large contact patch resulting in better traction on asphalt. Knobby tires provide poor traction on paved roads because only the knobs are in contact with the road. On off-road, the script flips because the knobs can dig into the ground.
However, since 23mm and 25mm tires are designed for road cycling, virtually all models are slicks.
Wider tires (25mm in this case) offer better traction thanks to the larger contact patch with the ground.
(If you want to maximize traction, it’s recommended to purchase the maximum tire width that the frame and fork can support. The tread of the tire should correspond to the terrain.)
The larger contact patch of 25mm tires and the potentially lower air pressure make cornering more stable too.
Wider tires increase the circumference of the wheel and technically make climbing slightly harder. It’s highly questionable whether this effect can be perceived when comparing 23mm and 25mm tires.
23mm tires result in better acceleration for the following reasons:
- Smaller circumference
- Lighter load
- Higher air pressure (potentially)
In general, narrower firm tires result in more direct handling. This is one of the reasons why some racers would put a 23mm tire at the front and a 25mm unit at the back.
That said, most people will not be able to feel a perceivable difference between the handling of a 23mm and 25mm tire. The effect is more pronounced when there’s a bigger gap between the tires (e.g., 23mm vs, 28mm).
It’s also important to note that heavier riders feel more comfortable on wider tires for their suspension effect. If you’re above 180lbs or so, 23mm tires could feel uncomfortable.
Most of the rider’s weight is on the rear wheel. Thus, one can replace only the rear tire with a wider one to benefit from the extra comfort.
Usually, narrower tires are more difficult to put on a rim. However, ultimately, it depends on the model.
In the past, riders used to ride on 21mm tires but those have gone extinct due to low demand. At the moment, the same is happening to 23mm tires. The vast majority of cyclists are not competing or do so at a lower level and thus have a low incentive to use a tire of that width. And since the pros are sticking with 25mm tires and up, the demand for 23mm is just not there.
Low demand = limited choice. That said, one can still find plenty of 23mm models. The options for 25mm are more abundant, however.
What’s better for commuting?
Wider tires are better for commuting. The ride is softer and more stable. There isn’t a practical reason to put 23mm tires on a commuter bike. One could even argue that they’re simply dangerous because the extremely narrow profile increases the chances of having your tire stuck in a drain or a hole.
The only exception that I could think of is the lack of clearance when using full fenders. But even in that case, it means that the frame and fork are simply too aggressive/race-oriented for commuting anyway, and thus it will be wiser to switch them up.
25mm tires are still not ideal for commuting (too narrow) but work considerably better. This is what I have on my retro road bike which I use as a workhorse. I have to run 25mm tires because I have full fenders. Otherwise, I could comfortably install 28mm tires.
The ideal tire for commuting on a road bike is 28-32mm. But if your options are 23mm or 25mm, 25mm will work sufficiently well.
What’s better for racing?
In theory, 23mm tires should have an edge when it comes to speed thanks to the lighter weight, the higher air pressure, the better aerodynamics, and the compatibility with more aggressive frames.
In practice, however, that edge does not make a perceivable difference and when you add the harsher ride that 23mm tires provide, it’s understandable why they’re no longer the norm even in racing.
At the moment, 25-26mm tires are the industry standard. And in many cases, riders go up to 28mm and even 30mm.
1. The air pressure at which 23mm and 25mm tires operate is very close. And when the air pressure is the same, the wider tire offers lower rolling resistance thanks to the smaller deformation (it remains closer to a perfect circle).
2. The weight discrepancy between 23mm and 25mm tires is too small to matter in practice.
3. The reduced drag of 23mm tires isn’t substantial.
4. Modern frames are very stiff, unlike the old steel ones. When you combine them with 23mm tires, the ride becomes uncomfortable.
Summary: What You Need To Know
The advantages of 23mm tires are:
- Slightly lighter when all parameters are equal (e.g., design, material…etc.)
- More clearance (compatible with very aggressive frames)
- More sharp/snappy/precise steering
- Aerodynamic (the tire does not protrude outside of the rim and minimizes drag)
- Faster acceleration
- Better climbing abilities
The downsides of 23mm tires are:
- Harsher ride
- Higher chance of getting stuck in a drain or a hole
- Slower than 25mm tires when the air pressure is identical
- More difficult to install (depending on the model)
- Not ideal for commuting
- Unfriendly towards heavier riders
The advantages of 25mm tires:
- Just as fast if not faster than 23mm
- More comfortable
- Better cornering
- Less likely to get “stuck”
- Better for commuting, although not ideal
- Functionally better than 23mm for racing
- Better for heavier riders
The disadvantages of 25mm tires:
- Slightly heavier
- Less aerodynamic
- Reduced clearance
The incentive to use 23mm tires is very small and practically non-existent if one isn’t looking for maximum speed in very specific scenarios. For the vast majority of people, 25mm tires would work better (if those are the only two options).