21mm or 23mm: Which is the common wheelset inner width?
Times are changing at a rapid pace. In our memory, the standard wheel width was always 19mm, and the tires were 23mm wide. We used to believe that narrower road tires meant higher tire pressure, which resulted in higher speeds. However, wider tires offer more comfort and have lower rolling resistance at lower pressures. With the increasing popularity of tubeless tires on road bikes, low tire pressure has completely changed the world of road bikes. The most important change is that road bikes have become more versatile and can now comfortably ride on rocky roads. Aerodynamic racing bikes can also be used for this purpose, while endurance racing bikes can be lighter and more aerodynamic.
Common road tires are now moving from 25mm to 28mm to accommodate wider tires. Purchasing wheelsets with an internal width less than 21mm seems to be outdated, as 23mm, 22mm and 25mm internal widths are becoming increasingly popular. This has led to road wheelsets evolving in two directions: 21mm and 23mm internal width. The question remains: What is the most common wheelset internal width?
From the perspective of the major international brands, Roval, Vision and Shimano are the 21mm school, Bontrager, Enve and Zipp are the 23mm school (the hookless wheelset is also 25mm internal width), and Campagnolo is moving from 21mm to 23 mm. It is a 50/50 split between 21mm and 23mm internal width.
From 19mm to 21mm: A magical transformation
To take full advantage of tubeless tires, it is recommended to start with an internal width of 21mm. This is because the larger internal width allows the tire to expand better and run at lower pressures, which is the main advantage of tubeless tires. It also prevents the tire from buckling and provides better lateral support, reducing the risk of the tire folding sideways at lower pressures.
From 21mm to 23mm: the tires are wider!
If you increase the width of your wheel by 2mm, e.g. E.g. from 21mm to 23mm, increase the width by 2mm. However, this change is not as significant as an increase from 19mm to 21mm. There is no noticeable difference in the tire's lateral support between 21mm and 23mm. However, the larger 23mm internal width allows the tire to expand an additional 1-2mm, meaning you can use a lower tire pressure (around 5-10psi) to achieve greater comfort without compromising rolling resistance . For example, if you put Michelin POWER CUP 25c tires on a 21mm wheelset, they will be 28mm wide. If you mount them on a 23mm wheelset they will be 1.4mm wider, i.e. h. 29.4mm wide. This effect is equivalent to wider tires without adding weight.
For those who don't want to use tubeless tires, we recommend a wheelset with an internal width of 23 mm. The reason for this is that the tube takes up some space and reduces the air capacity of an open tube tire compared to a tubeless tire. Therefore, the tire pressure must be increased by 5-10 psi for the same tire width and rider weight. The 23mm wheelset can in most cases compensate for this disadvantage compared to a 21mm wheelset as the tire can expand further. However, it still cannot be used with ultra-low tire pressure like tubeless tires as this may result in a flat tire due to snakebite.
23mm inner width is more suitable for 28mm tires
It wasn't long ago that only endurance road bikes used 28mm tires. However, 28mm has now become a road bike tire that is more comfortable than 25/26mm tires. Sometimes comfort also means speed. The internal width of 23mm is more suitable for 28mm tires than 21mm. Typically, the external width of a wheelset with a 23mm internal width is 30mm or more. This is a more aerodynamic fit for 28mm tires.
conclusion
The 21mm and 23mm wheelsets generally have similar internal widths. Both the 21mm hookless wheelsets and the 23mm hookless wheelsets are suitable for tubeless tires, and there is little difference in their actual usage. However, the 23mm internal width for open tires is more suitable for lower tire pressure (21mm internal width) and offers more comfort. If you are a heavy rider who wants to use 28mm or wider tires, the 23mm internal width is more advantageous.