The relationship between wheels and tires is certainly interesting.

And since tires are consumables, the question of what size to get next, and how the wheel and frame will match, can be both fun and challenging.

Here, we will primarily look at this from a size perspective.

1. The Remarkable Evolution of Road Bike Tires

① Re-evaluation of Rolling Resistance

Road bike tires previously favored 23C, but now 25C to 28C are the mainstream. While it might seem that narrower tires are faster, recent discussions suggest that, for bicycle tires, a certain degree of width can actually reduce rolling resistance.

The theory is that if the load on the tire is the same, 25-28C tires have a shorter contact patch length compared to 23C tires, which means less tire deformation and thus reduced rolling resistance.

So, what's the best size for a road bike? It seems the current mainstream of 25C to 28C is the optimal solution.

While 32C is an option, it hasn't become mainstream due to concerns about frame compatibility, increased weight, and increased air resistance.

② The Emergence of Gravel Roads

In recent years, the gravel road genre has been established. The tires on these bikes are quite wide, ranging from 32C to 43C. This shift is due to the addition of factors like off-road capability and comfort, rather than just the high speed and climbing ability prioritized in pure road bikes, leading to a new optimal solution. For gravel bikes, wider tires offer more benefits, even if it means sacrificing some riding performance.

With this diversification of demand, tires are also becoming lighter and higher-performing.

In the future, we may see many instances where conventional wisdom is overturned. We must keep a close eye on these developments.

③ The Spread of Tubeless Systems

The shift to tubeless tires is also a major trend.

From the perspective of rolling resistance mentioned earlier, tubeless systems are superior. This is because the absence of an inner tube reduces friction between the tube and the tire/rim inside the tire. However, in terms of weight reduction, the weight of the sealant injected is almost equivalent to that of a tube, so there hasn't been a dramatic improvement in this regard yet.

While they are less prone to punctures, it is true that in the event of a flat while out riding, tubeless tires are more cumbersome to repair than clinchers, and we particularly look forward to advancements in this area.

2. The Deep Relationship Between Tires and Wheels

Let's look at the matching of tire width and rim width.

Considering aerodynamics, the following relationship is desirable:

Outer rim width : Tire width = 105 : 100

From this, it can be said that simply putting overly wide tires on conventionally used wheels can potentially lead to matching problems for road bikes. Here's a guideline for what is considered appropriate:

23C tire → 15C inner rim width (23-32mm outer width)

25C-32C tire → 15C-17C inner rim width (23-50mm outer width)

28C-42C tire → 19C inner rim width (28-62mm outer width)

There's a range and overlap because even with the same stated size, actual measurements can vary for both tires and rims, and tires have flexibility.

While wider rims are a disadvantage in terms of weight, they are advantageous in terms of rigidity, and this seems to be a key factor in predicting future trends. This balance might be where manufacturers and users who choose them can really show their skill.

3. In the Case of ICAN Wheels

ICAN is a comprehensive sports bike manufacturer specializing in sports wheels.

ICAN road bike wheels come in the following series, all made of carbon. Many models are available in disc brake compatible versions:

• AERO Rim width 25mm, Heights 35, 40, 45, 50, 55, 86mm
• Alpha Rim width 25mm, Heights 35, 40, 45, 46, 50, 55, 86mm
• FL Rim width 25mm, Heights 40, 55, 50mm
• NOVA Rim width 25mm, Heights 25, 35, 40, 45, 50, 55mm
• CBW Rim width 23mm, Heights 38, 50, 86mm

These models are produced with the latest technology, incorporating trends in road bike tires. Please check out the wide variety on the following page.

【ICAN Wheel Official Website】

4. Conclusion

This time, we focused on the relationship between tires and wheels, but wheels are currently undergoing many waves of innovation. The shift to disc brakes is one significant wave.

As we've already discussed in ICAN's blog, as road cyclists, we can't help but be sensitive to new information.

We intend to continue sharing as much as possible here as well.

Please keep an eye on ICAN's future developments.

【Reference Article】

Road Bike Brakes: Disc Brake Edition