Pro Vibe Di2 Stem

This incarnation of the Pro Vibe Di Stem focuses on aerodynamics and the latest technology used in electronic gear systems to turn your bike into a smooth-looking, wind-cheating work of art. Form is backed up by function, with a component that excels in stiffness without carrying any extra weight.

We took a look at the Pro Vibe 7S stem last year and were mightily impressed, so it's great to see that the engineers at Pro haven't meddled with its performance at all.

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This new Vibe is unbelievably solid in use but without giving any feeling of harshness over rough surfaces. The differences in comfort levels and reduced road buzz are pretty marginal compared with most other aluminium alloy stems, but still noticeable.

The front end has some bulk to it, to resist those forces transferred from the handlebar when you are really going for it in a sprint, for instance, or heavy braking and steering on a steep technical descent. The rest of it is reasonably svelte though, and I especially like the octagonal style shape with its black-on-black logos.

The front clamp has gone back to a four-bolt design, although the holes have been moved to the rear to keep them out of the airflow. The benefits will be minimal, it's not something you're going to notice in the real world, but it does look smart.

To make setup and adjustment easier, the bolt holes are threaded into the faceplate at an angle. The trouble is, the hex keys on most multi-tools won't be long enough to prevent you fouling the stem body. This can make roadside tweaks a pain.

The Vibe is designed to be paired with the carbon fibre aero handlebar of the same name, which I've also reviewed, with both being aimed predominantly at the Shimano Di2 electronic shifting market. Pro being Shimano's component arm, it's no surprise that there's collaboration between the two.

The Vibe handlebar has an exit hole at the rear which allows the battery cable to travel from the bar, through the stem body, and out of the hole you see above the steerer clamp in the photo. This means that if you use a fork steerer-mounted Di2 battery, everything is hidden from view.

A quirky shaped top cap (not shown) keeps the lines smooth over the top of the cable but this obviously means that it'll only work if your steerer is cut short. There is the option of leaving the steerer longer, poking out above the stem, but you will require a special spacer.

Weight-wise it's not in the same league as Deda's more expensive Superleggero at 124g or the Superlight from Aerozine at less than half the price and 40g lighter, but the Vibe certainly feels hefty and I'd rather have the stiffness anyway.

> Tour Tech 2017: The stems the pros are using

For £99.99 the Pro is at the more expensive end of the alloy stem market, but I wouldn't really say it's overpriced. It's a very good piece of kit and you'll find it adorning plenty of pro bikes in the peloton so it can't be bad.

With or without the matching Vibe bar, this stem is a good choice for those riders who want a reasonably light but very stiff stem.

Verdict

Super-stiff peloton-proven performance with added neat aero tweaks for Di2 users