K-Edge HMS Max XL Combo Mount

The K-Edge Hammerhead Max XL Combo Mount is designed for, and approved by, Hammerhead to mount your Karoo 2 out front of your stem, with a GoPro-style mount below the computer mounting point for a front light or camera. It looks sleek, is made from aluminium and held my Karoo 2 solidly, and a light below it securely. It's rather expensive, though.

Yet to decide on a GPS unit? Check out our guide to the best cycling computers – including the Hammerhead Karoo 2.

This Hammerhead mount is CNC machined from aluminium in Boise, Idaho, and looks and feels like a premium product. K-Edge is very specific about payloads: on top you're allowed 123g (ie a Karoo 2) and below, you're good for 242g.

I like this style of out-front mount with GoPro underneath. I think it's the perfect place to mount a small front light like the Ravemen CR450.

The mount isn't hard to install. It's designed for 31.8mm handlebars but comes with a shim for smaller diameters. The clamping part is hinged, and goes around the handlebar easily, and you tighten it up with a 3mm hex key, accessed from below.

On the one hand, this looks neat as the bolt isn't visible; on the other, if you're swapping it frequently, access from the top (like you get with the Bar Fly 4 Max I've been using for ages) would be easier, less faffy, and my preferred option.

If you also want to mount a front light made by Niterider, K-Edge sells an adapter separately to make this a cinch. If you want to use a front light from a different brand, though, you'll need to go adapter hunting as it's not universal – unlike the adapter you get with the Bar Fly.

Position

Once installed, the mount sits out front with the Hammerhead aligned with the top of the bar. For maximum aero. I think.

You can get a spacer kit if the alignment doesn't work out quite right on your setup, but on mine it sits just right. This spacer kit also comes with a spare Karoo insert – the one part that could potentially wear out – so as that is replaceable, this mount should last a long time.

My Karoo 2 was held solid during the testing period, and the front light that I mounted below didn't complain either, though I did need an adapter to mount it. It would have been nice to see some sort of generic adapter included, like you get with the Bar Fly (see above).

This mount places the Karoo 2 with enough space between the stem and the charging port that you can get some USB-C cables in there. This is important if you're planning any rides that will take more than about eight hours as you'll need to charge your Karoo 2 on the go. I had to buy a charging cable from Amazon that fits in that space.

You can also get a K-Edge Hammerhead Mount without the GoPro mounting, if you want to spend a bit less and are not bothered about being able to hang something underneath. For completeness, you can also get a Boost Stem Mount option, as shown below.

Value

Like I said above, I like this style of head unit mount; I've been using a Bar Fly 4 Max for this purpose for ages, so I was interested to see how the K-Edge compared.

The Bar Fly is less than half the price (it costs £33), is 7g lighter, and does exactly the same thing (including having enough space for a charging cable). But it's made from plastic and doesn't use the Karoo 2-specific mount; I've been using it with a quarter-turn Garmin adapter.

To mount a front light below the computer on the K-Edge you need another adapter, while the one the Bar Fly 4 Max comes with is universal, making the K-edge even more expensive for this use case.

So, can I honestly say that you should spend £89.99 on the K-Edge? Well, it looks better than the Bar Fly, and it has the Karoo 2-specific mount. It's up to you whether that's worth spending nearly three times the money.

And there are cheaper options still if you don't want the GoPro mount. Hammerhead's own mount is £40, and if you're happy to go with the Garmin-style quarter-turn adapter that your Karoo came with then the Lifeline Out Front GPS Computer Mount can be had for £10.49 on Wiggle at the moment, down from £14.99.

Conclusion

This K-Edge Hammerhead mount works well, and does everything you'd want it to do. The sticking point is the cost, as other options are available at less than half the price. It's up to you whether you want to spend more for the Karoo 2-specific mount and the sleek looks; I'd find it hard to justify.

Verdict

Great mount, but equally good alternatives are available at less than half the price