Bontrager Wide Wheels

Bontrager has been busy of late, launching a whole range of new products; everything from a revamped XR4 tyre (including a big 29x2.55 version) through to new 35mm diameter handlebars and a Bontrager dropper post. For us however, the most interesting development has been in their wheel department.

There’s a clear trend towards wider rims at the moment. For many years XC rims sat around 17-20mm wide (measured internally) and burly trail/all-mountain wheels were in the 21-24mm range. Now many smaller brands offer rims that are in the 27-35mm range but most of these have been pitched at the trail or enduro markets where wide tyres are the norm.

Meanwhile, most big-name wheel brands have been extremely conservative. While their marketing departments talk of wider rim offerings, they’re often in the 21-23mm range.

So what’s all the hype over wide rims? Well the advantages are many (read more about it here) but the main point is that they offer better support for the tyre casing. As a result, your tyres aren’t as dependant on tyre pressure to prevent squirm and sideways roll under hard cornering. This in turn means that you can use lower tyre pressures for better traction and comfort and the risk of tyre burping is greatly reduced. There’s also the option of using lighter, narrower tyres for a faster roll without suffering a major compromise in cornering traction.

We’ve been fans of wider rims for some time, and not just in wide tyre gravity enduro applications; we’ve had good success running 2.2 inch XC rubber on 31mm internal rims. The main disadvantage of wide rims tends to be weight, but modern composite construction is going a long way towards minimising the weight gain.

Over the past six months we’ve noticed a few high-profile XC racers sporting rims that appeared to be very wide and now it’s clear that it wasn’t an illusion. Trek’s World Cup racers have been riding and testing new wheels and now the end product is out, and it’s properly wide. The new Kovee XXX wheels measure 29mm in between the bead hooks, which is exceptionally wide for a top-flight XC race wheelset – we’ve seen ‘plus’ tyred bikes with skinnier rims than this!

Despite their girth, the carbon rim is said to weigh just 375g and the complete 29-inch wheelset comes in at 1,390g. They also feature 54-point engagement on the DT Swiss Star Ratchet hub. The only catch seems to be that the wheels will only be offered to suit the new 110/148mm ‘boost’ hub standard, which will limit the aftermarket appeal of these wheels.

To complement the Kovee, Bontrager will also have the Line XXX. This will be a slightly sturdier version of the Kovee with a 435g rim that’s aimed at the trail and all-mountain market. The Line XXX wheelset will be offered in both 27.5 and 29er sizing and is expected to weigh 1,535g (27.5) or 1,625g in the 29er version. Both the superlight Kovee and Line XXX rims share the same 29mm internal rim dimension.

Bring it on we say!