WTB CGR i28: Wide carbon wheels for the next generation of gravel bikes?

​Gravel tyres are getting wider and wider. WTB has responded to this trend with the new CGR i28, a carbon wheelset with a 28-millimetre rim width and a 40-millimetre-high rim. The Californian company promises greater stability, high durability and benefits for modern gravel tyres. But the real star of this new product may well lie in the hubs.

Anyone looking at the latest gravel road bikes will quickly spot a clear trend: larger tyre volumes, lower air pressures and increasingly challenging terrain. Whereas just a few years ago, 40-millimetre tyres were considered generous, many manufacturers are now opting for widths in excess of 50 millimetres.

It is precisely with this trend in mind that WTB has developed the new CGR i28. Rather than focusing on maximum aerodynamics or minimum weight, this wheelset concentrates on how modern gravel tyres can be optimally supported.

Why WTB opts for a 28-millimetre internal width

What is particularly noteworthy here is not so much the 40-millimetre-high carbon rim as the chosen internal width of 28 millimetres. Whilst many manufacturers are following the trend towards ever-wider rims almost unchecked, WTB takes a more nuanced view.

The Californians regard 28 millimetres as the ideal compromise for gravel tyres, which range in width from 45 to 54 millimetres. Even wider rims could spread the tyre tread too much. This would alter the shape and potentially affect characteristics that tyre developers have specifically tuned.

That sounds reasonable. Whether 28 millimetres will actually become the new standard, however, is likely to depend heavily on future trends in tyre widths. In the gravel segment, standards are currently evolving more rapidly than in many other cycling categories.

The most exciting new feature is in the hubs

The new Frequency 7X hubs are at least as interesting as the rims. WTB emphasises that the system has already been used by Cannondale Factory Racing in World Cup races. Such claims should, of course, always be taken with a pinch of salt. For gravel riders, however, it’s likely to be more important how reliably a wheelset performs after several winters, rides in the rain and in muddy conditions. According to WTB, this is where the development comes in

The freewheel gearing is given a DLC (diamond-like carbon) coating, which is designed to reduce friction and wear. Another striking feature is the design of the inner gear ring. Instead of a conventional threaded connection, a toothed connection is used. According to the manufacturer, this is intended to enable significantly higher loads whilst also simplifying maintenance.

Added to this are larger-than-average enduro bearings. These are designed to increase durability and extend service intervals, particularly when the bike is coasting. These aren’t spectacular features, but in everyday use they can be far more important than saving a few grams in weight.

Designed for fast gravel races and long adventures

WTB positions the CGR i28 as a wheel suitable for both gravel racers and bike packers. The combination of a wide rim bed, a deep carbon profile and robustly designed hubs is clearly aimed at riders who don’t just ride their gravel bikes on well-maintained country lanes.

This is complemented by the company’s own TCS tubeless technology and the asymmetrical rim design, which is intended to ensure more balanced spoke tension. Additional reinforcements around the spoke holes are designed to improve durability.

Free replacement in the event of damage to the rims

The warranty promise is unusually generous. If a carbon rim breaks whilst riding, WTB states that it will replace it free of charge, provided the buyer is the original owner of the wheelset. Whilst such schemes are becoming increasingly common in the industry, they also highlight just how important trust has become when it comes to high-priced carbon products.

Technical specifications: WTB CGR i28

Prices

According to the manufacturer, the new WTB CGR i28 will be available from the end of September through specialist retailers and European distribution channels.