The Rise of Wider Internal Rim Widths: Is 25mm the New Standard?

In the past decade, road cycling has undergone a quiet but transformative shift: wheels are getting wider. What started as a trend in mountain biking has now reshaped road and gravel wheel design.

But with more brands offering 25mm internal rim widths, many cyclists are asking:
Is 25mm the new standard? And should you upgrade?

Let’s break down why wider internal rim widths are gaining popularity, what they mean for tire performance, and whether a 25mm rim is right for your riding style.

 What Is Internal Rim Width?

The internal rim width (IRW) is the distance between the inside walls of the rim, where the tire beads sit. It directly affects:

Tire shape

Ride comfort

Rolling resistance

Cornering stability

Over the years:

Old standard: 15-17mm (narrow)

Modern road wheels: 19-21mm

Gravel wheels: 21-25mm+

Emerging trend: 25mm internal width for road and gravel

Why Wider Rims Are Becoming the Norm

1. Wider Tires Are Now Standard

25C and 28C tires have replaced the old 23C road tire standard. Wider tires work best with wider rims for proper sidewall support.

2. Lower Rolling Resistance

Wider rims allow tires to spread out more, increasing the contact patch without increasing pressure, which can reduce rolling resistance.

3. Improved Cornering Stability

Wider rims improve the tire’s sidewall shape, making cornering more predictable and safer, especially at lower pressures.

4. Better Ride Comfort

Lower pressures made possible by wider rims and tires absorb road vibrations and improve long-distance comfort.

5. Enhanced Tubeless Performance

Tubeless setups seal more reliably on wider rims and handle lower pressures better, reducing the risk of pinch flats.

Is 25mm the New Standard?

It’s rapidly heading that way for several cycling disciplines:

Gravel Bikes: 25mm is already common and allows for tire widths up to 50mm or more.

All-Road/Endurance: Many brands now offer 23-25mm internal rims paired with 28C-40C tires.

Aero Road Bikes: Some modern aero wheelsets now come with 23-25mm internal widths to fully integrate wider tubeless tires.

However, race-focused road bikes may still use 21mm or 23mm widths for aerodynamic optimization with narrower tires like 25C or 28C.

Pros and Cons of 25mm Internal Width

Feature	Pros	Cons
Tire Compatibility	Supports 28C-50C easily	May not suit narrow tires well
Comfort	Lower pressure, more compliance	Slightly heavier rim
Cornering	More stable, better grip	Requires correct tire pairing
Aero Efficiency	Better with wider tires	Can lose aero with skinny tires

Should You Upgrade to 25mm?

Upgrade if:

You mostly ride gravel, endurance, or mixed-surface routes.

You prefer 30C or wider tires.

You prioritize comfort, stability, and versatility.

Consider sticking to 21-23mm if:

You race frequently and still prefer 25C-28C tires.

You ride primarily on smooth, paved roads and want to maximize aero gains.

You already have a wheelset optimized for narrower profiles.

Final Thoughts

The shift toward wider rims, especially 25mm internal widths, isn’t just a trend—it’s a response to the modern cyclist’s preference for wider tires, lower pressures, and more versatile performance.

While 25mm rims are rapidly becoming the new all-road and gravel standard, your ideal rim width should always match your tire size, riding discipline, and personal comfort preferences.