ITM X-One Carbon Stem with GWS Grip Wedge System

It may be a bit of a 'chunky monkey' at 219g, but the X-One Carbon Stem with GWS, from Italian brand ITM, is one of the stiffest stems on the market. It's a rather stunning looking piece of design for your pride and joy too. Just don't expect to attach your computer to it.

It's all a bit old school having to feed your handlebar through a hole in the stem, just like the days when we were all riding quill stems (you young 'uns will have to ask your parents). You had to learn the knack of twisting and turning to feed your brand new bar through without leaving a scratch on it, just like playing one of those games where you feed the loop over the wire without the buzzer going off.

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The X-One is a little different because it has a teardrop opening to accept the shape of the X-One Carbon bar (review to follow) to create a semi-integrated system. Once the 31.8mm diameter bar centre is in place, it's held there by the Grip Wedge System, a snappy title but it does the job it needs to.

It does have a little niggle, though: the position of the bolt which, when tightening, makes the system expand by pulling the three pieces together. If you are using the X-One bar with its wide, flat tops, you struggle to get an Allen key in there without catching the back of the bar; a torque wrench with adaptor is even trickier.

For the initial setup I didn't use any carbon gripper paste between wedge and bar, to see whether anything moved under heavy braking or hitting a pothole; it did, but after a couple more tweaks of the bolt, things have stayed secure.

The theory behind the one-piece construction is to create stiffness by omitting the faceplate and securing bolts. It also provides minimal aerodynamic gains, and looks mighty fine.

Stiffness is where the X-One excels. Its wide, squarish profile uses a lot of material, hence the weight, but get out of the saddle and wring the bike's neck and you won't feel the tiniest bit of movement through the stem body whatsoever.

At the steerer end, the X-One is quite deep. I had to remove my only remaining 5mm spacer, so if you've already slammed your stem you might need to check the fit.

The X-One is actually designed for a 1 1/4in diameter steerer, but you also get a shim to bring it down to 1 1/8in. It does take away that one-piece design mantra for the majority of road bikes, but you don't notice any issues.

All this is finished off with ITM's specific teardrop shaped top cap.

> Find more road.cc reviews of stems here

If you like to mount your GPS/computer on your stem you'll find that because of its shape and width, the X-One doesn't really lend itself well to the likes of Garmin's rounded mounts, and if you're using the X-One bar there'll be nowhere to mount it there either.

Another negative for me is the 'Ride Your Best' tattooed down the centre of the stem. I'm not one for motivational quotes at the best of times, let alone when I'm out on my bike having a bad day and having to constantly read that...

One thing to bring a smile back to your face, though, is the price – well, it'll make you chuckle either way, I suppose. To my mind, £129.99 is quite competitive against the top performing alloy stems, and quite a bit cheaper than other full carbon stems on the market.

Overall I really rate the X-One stem. I can overlook its slightly porky weight for the stiffness you get for really speedy riding. It's got a few niggles, yeah, and I'd like to see a little bit more care taken with the internal finish – it's a little rough around the inside of the steerer hole (would it really take much to rub a bit of sandpaper around when it comes out of the mould?) – but on the whole it's performance that matters, and I love it.

Verdict

A very good stem for the sprinters because of its phenomenal stiffness, but its weight will upset the weight weenies