Smith Mainline Helmet Review


A Simple Mount That Makes a Big Difference

Review by Robert Johnston| Photos by Adam Mcguire/Robert Johnston

You may have a Wahoo or Garmin cycling computer already, or be about to unwrap one from under the tree. Either way, the chances are the supplied mounts aren’t quite giving you the perfect central position that’s easy to see when you’re hitting the trail hard. This makes the aftermarket computer mount market very worth exploring, as a little cash can vastly improve the usability of your flashy cycle computer. Nukeproof knows this, and designed their Horizon Over Stem Garmin mount to provide what they reckon to be the ultimate position for a cycling computer on a mountain bike. Read on to find out if it’s the one for you.

Smith Mainline Helmet Review


Simple as can be, the Nukeproof Horizon Over Stem Garmin mount places the cycling computer directly above the bar clamp portion of a mountain bike stem to position it where it’s most visible, without interrupting your view of the trail ahead. The mount sits around a 1 1/8th” steerer tube, taking the place of 7mm worth of steerer spacers and thus using the headset compression to fix tight. This then requires at least 7mm of steerer tube above your stem in order to mount it, so those with fully trimmed steerers may struggle. The mount is optimized to sit flush with a Nukeproof Horizon stem, but will fit most other mountain bike stems without issue due to its rise.

Smith Mainline Helmet Review

The mount is CNC’d out of 6061 aluminum, anodised and laser etched with the Nukeproof graphics. A generic polymer insert offers compatibility with anything that uses the ¼ turn mount standard, meaning it’ll of course fit a Garmin computer, as well as Wahoo units and some other items such as a Moon light. The orientation of this mount can be rotated 90 degrees to work with any of these, thanks to the two hex key bolts.

The Nukeproof Horizon Over Stem Garmin mount is available in the 6 regular Nukeproof Anodised finishes, and retails for £24.99 /$36.99 /€29.99.


Fitting the mount couldn’t really be simpler. Mine went onto a fresh setup with an uncut steerer, so I was sure to account for the mount in my length calculation, but many will have the room anyway. If you don’t have any spacers above the stem, but have some below, then perhaps it’s a good excuse to upgrade your bars at the same time and get a slightly higher rise, as the position this mount puts your computer in is as good as I’m yet to experience. Unlike a top cap mount, or an off-center bar mounted solution, the computer ends up directly below the line of your vision as you look down the trail, keeping the trail within your peripheral if you take a quick glance down. It looks sleek, and stayed perfectly solid on the steerer as long as there was adequate tension in the headset.

Smith Mainline Helmet Review

It’s not all rosy though unfortunately, as the way that the mount protrudes above the steerer means the mount itself (and even more so the computer) is the highest point on the bike unless you’ve got some seriously high bars. This means that flipping the bike on a hard surface will damage them, so be wary when doing so. If the bike has ended up upside down on the bars in a crash I’d suggest you’ve got bigger things to worry about, but it may spell the end of your computer, not that every other mount position and style keeps them safe either. The polymer insert did break on mine when removing a tight-fitting computer in -4 degC, but it may have been damaged beforehand. Thankfully the CNC’d portion of the mount is plenty strong, so sourcing a replacement insert is not an issue as they are cheap and easy to find.

Though we’ve missed the stocking filler period of gift giving, perhaps this is a good thing to spend any cash accrued from a christmas card, or just a chance to treat yourself to an item that’ll enhance your experience using a cycling computer as a training tool. Either way, it seems like a solid buy for a Garmin or Wahoo using rider.

Smith Mainline Helmet Review

The Wolf’s Last Word

A cheap and effective solution that can enhance your cycling computer experience, the Nukeproof Horizon Over Stem Garmin mount is a product I’m thankful for – it’s the simple things that often make the biggest difference.

Price:  $36.99 /£24.99/ €29.99

We Dig

Simple and Effective
Clean look
Ideal computer position

We Don’t

Potential damage

Broken polymer insert


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