First Look: Box Components 35mm MTB Cusp Stem and Carbon X Bar

Box Components has been teasing us for a while with some great looking mountain bikes components that while very intriguing, weren’t yet available to the public. The fact that we have a set of the Box X Bars and Cusp stem in our possession is big news for the company as they expand from their roots in BMX to the world of mountain biking. Not that the company lacks mountain biking heritage – after all, it is founded by the Toby Henderson.

Borrowing from their line of award winning BMX bars and stems, the first Box mountain bike cockpit aims straight for the top with a 35mm carbon bar and matching 3D forged aluminum stem. On paper the combination should be competitive in both weight and price. Full details including actual weights next…

One thing’s for sure, thanks to the unique design of the X bar there is no mistaking it for the competition. Available only in 35.0mm diameter, X bars will be offered in specific rise and width combinations. The bar above is what they consider their low rise trail bar which comes in at 760mm wide and with 15mm of rise which will retail for $139.0.

Other bar options will include:

• XC :    700 wide, 6mm rise, 7 back, 5 up, 160 grams   $129.00
• Trail: 780 wide, 30mm rise, 9back, 5 up, 195 grams    $139.00
• DH:   800 wide, 15mm rise, 7 back, 5up, 235 grams    $149.00
• DH:  800 wide, 30mm rise,, 9 back, 5 up, 245 grams   $149.00

Other than the Box logo, you’ll find minimal graphics on the bars. Those that you will find on the center of the bar will help you ensure the bars are perfectly centered and will aid in dialing your ideal rotation.

Here’s the thing about handlebars – you can always cut them down. More than likely, 760mm will be wider than many will want for a trail bike so go ahead and cut ’em. There is even handy labeling on the bar ends that tells you exactly what length bar you’ll end up with if you cut here. Just make sure to try the bars in the wider setting first. I started riding 750mm bars on my “enduro” bike this year and haven’t considered going back. But 760mm? We’ll see…

The new 35mm bar and stem diameter is slowly creeping into the mountain bike world, but 31.8mm still remains the most prevalent. Of course as more companies like Box Components add their 35mm options to the mix, that will probably change. In order to hold the 35mm X bar in place, Box puts forth their Cusp aluminum stem. The use of 3D forging makes for a light weight but very strong stem that requires a lot less post machining.

Named for the concave shape of the stem body, the Cusp mirrors the design found on the Mini Cusp 28.6 BMX stem.

Using 4mm hardware at both ends, the Cusp features a carbon steerer tube friendly clamp as well as wide contact points for the bar.

The handlebar markings line up nicely with the stem for easy adjustment of the fore/aft rotation of the bar. For fans of slam-that-stem setups, the Cusp has a fairly low stack height.

Built with a 0 degree rise, the Cusp Trail stem will be sold in 45, 55, and 65mm versions in a number of colors for $99.99.

At 186g for the bar, the 760mm X bar is just 6g over claimed weight but within their +/- 10g variance. That also makes it very competitive with the competition. The Cusp stem turned out a bit heavier than the 140g Box was shooting for when Tyler checked in with them at Interbike (Colin with Box told us his simulation numbers for this stem came out to 163g). We haven’t had the chance to weigh production versions of many 35mm mtb stems, but based on claimed weights the Cusp may be on the heavier side (by 10g or so)  but it is also one of the least expensive. We’ll see how it stacks up once we get the weights of the competition.

We’re told the 65mm Cusp stems will be available in all colors by the end of December. The 45 and 55mm versions will follow up with all colors available by the end of January. The carbon bars are available now.

boxcomponents.com