Mountain bikes initially used 26-inch rims, derived from road bikes and beach cruisers. For a long time, 26-inch rims dominated due to their durability, agility, and light weight. However, as mountain biking evolved, the limitations of 26-inch rims in cross-country (XC) racing became apparent, particularly in terms of clearance. To address this issue, 29-inch rims were introduced. In 2009, Jeremy Horgan-Kobelski won the US XC Championship using a 29-inch mountain bike, demonstrating the advantages of larger rims in terms of clearance, stability, rolling distance, and cruising speed.
Despite the many advantages of 29-inch rims, they also have drawbacks such as increased rotational inertia, heavier wheels, harder starts, and more challenging handling, which sparked debate among professional riders. Consequently, the 27.5-inch rim emerged as a compromise. This size combines the benefits of both 26-inch and 29-inch rims, offering good clearance and manageable handling, making it easier for riders accustomed to 26-inch bikes to adapt. Theoretically, 27.5-inch rims have 3% better clearance than 26-inch rims and offer faster cruising speeds. Today, 27.5-inch rims have become the mainstream size for mountain bikes, validated by the market.
This variety leaves many uncertain whether to choose 26-inch, 27.5-inch, or 29-inch rims. Generally, larger rims provide better clearance, while smaller rims offer better agility. Typically, 26-inch rims are more suited for city paved roads, 27.5-inch rims cater to more diverse riding needs, and 29-inch rims are best for mountain cross-country riding.
Different rim diameters greatly affect riding experience. Switching from 26-inch to 27.5-inch rims initially feels significant, but you quickly adjust because the difference isn’t too drastic. However, switching from 26-inch directly to 29-inch rims can be overwhelming due to the substantial difference. One inch equals 2.54 centimeters, so a 26-inch rim has an actual diameter of 66 cm, and a 27.5-inch rim has a diameter of about 70 cm. We know that a larger diameter means a larger circumference, which means a 27.5-inch tire covers about 12 cm more ground per rotation than a 26-inch tire, and a 29-inch tire covers about 12 cm more than a 27.5-inch tire.
Currently, 27.5-inch rims dominate the market, with many major manufacturers ceasing production of 26-inch rims, likely signaling a future trend towards phasing out 26-inch rims. If your primary need is mountain cross-country riding, opt for 29-inch rims without hesitation. For daily commuting or city riding, 27.5-inch rims are your best choice. In such cases, 26-inch rims are still an option but not the optimal one.
Considering rider height, if you are taller than 180 cm, we strongly recommend 27.5-inch or larger rims for a more proportionate appearance. For those under 180 cm, both 26-inch and 27.5-inch rims are acceptable.
By the way, SUMLON has been manufacturing bicycle parts for over 15 years. Contact us if you are looking for a bike parts factory or a one-stop wholesaler. Peace
