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PRO's new Vibe Carbon Stem is a very good option for stiffening up the front end of your bike. The slim design and low weight are very impressive, just watch out for the low torque setting on the top cap.
You wait ages for one carbon stem to arrive and then two come along at once. I'd only just fitted the Zipp SL Sprint stem when the Pro Vibe Carbon arrived for testing. Still, it's a great chance to ride them back to back and see how two very different designs work.
Both are claimed to be very stiff but Pro and Zipp go about delivering this in very different ways. Where the Zipp has a very chunky design, the Pro Vibe is still quite slender. I really like the design of the Pro Vibe. It doesn't look out of place on a skinny-tubed bike and the slim form factor means that space on narrow bars isn't going to be an issue.
Getting my head down and opening up a sprint or two suggested that there are no stiffness issues here. The Pro Vibe is a solid platform that I couldn't twist, even on the steepest power climbs where I really start wrenching on the bar.
Pro has redesigned its 'puzzle' clamp for the new Vibe carbon stem. The two alloy pieces that make up the faceplate hook onto protrusions on the stem, and everything is brought together by two alloy bolts. It's a clean setup that looks great and is easy to install.
Talking of installation, this is where I found my one and only gripe with the Vibe Carbon stem. The top cap is also carbon and comes with a very strict 2Nm torque limit. If you exceed this, you're in danger of pushing the top cap bolt straight through the carbon.
This isn't really an issue, I'm just warning you. If you've got a difficult setup that requires you to put a bit more pressure on the top cap then you can simply use an alloy top cap to set the preload, nip up the steerer bolts and then pop the carbon top cap on in place of the alloy cap.
The stem's faceplate design allows you to use the stem in either the -8 degree or the +8 degree option. There are no other tilt options, but I find that -8 is a good choice for a stem that is going to be primarily used on race bikes. You're well served for lengths, though: the Vibe Carbon stem comes in 10mm increments from 80mm to 130mm. The 120mm that I have here tips our scales at 147g, an impressive weight given the stiffness. Zipp's SL Sprint in the 110mm was 173g.
At £249.99 it's just a few quid less than the Zipp SL Sprint at £254. Both are premium options, but both work perfectly.
As with Zipp's SL Sprint, you're likely buying the Pro Vibe Carbon for the stiffness, and it really delivers. You also get a smaller form factor than the SL Sprint, and a lower weight too.
Stiff and slim design is a real winner
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road.cc test report
Make and model: Pro Vibe Carbon stem
Size tested: 120mm
Tell us what the product is for and who it's aimed at. What do the manufacturers say about it? How does that compare to your own feelings about it?
Pro says: 'Full carbon construction. No compromises'
Tell us some more about the technical aspects of the product?
Super lightweight and stiff with an aerodynamically optimised design
Next evolution of PRO's Puzzle Clamping System for total security
Fully Di2 compatible
Reversable design, can be installed either +8° or -8° for a completely customisable ride
Weight from 120g
31.8mm clamping diameter
Available in 90 to 130mm lengths
It's a little cheaper and a little lighter than the Zipp.
Tell us how the product performed overall when used for its designed purpose
Perfectly. I couldn't get this thing to flex at all.
Tell us what you particularly liked about the product
The stiffness provided from the slim and lightweight design is very impressive.
Tell us what you particularly disliked about the product
The top cap is a little delicate.
How does the price compare to that of similar products in the market, including ones recently tested on road.cc?
About the same as the Zipp SL Sprint, just a few quid less.
Did you enjoy using the product? Yes
Would you consider buying the product? Yes
Would you recommend the product to a friend? Yes
Use this box to explain your overall score
Load of stiffness from a slim and lightweight design. Just watch the top cap.
About the tester
I usually ride: Cannondale Supersix Di2 My best bike is:
I've been riding for: 5-10 years I ride: Most days I would class myself as: Expert
I regularly do the following types of riding: road racing, time trialling, cyclo cross, commuting, club rides, general fitness riding, I specialise in the Cafe Ride!
Son of a Marathon runner, Nephew of a National 24hr Champion, the racing genetics have completely passed him by. After joining the road.cc staff in 2016 as a reviewer, Liam quickly started writing feature articles and news pieces. After a little time living in Canada, where he spent most of his time eating poutine, Liam returned with the launch of DealClincher, taking over the Editor role at the start of 2018. At the weekend, Liam can be found racing on the road both in the UK and abroad, though he prefers the muddy fields of cyclocross. To date, his biggest race win is to the front of the cafe queue.