The Primavera Carbon stem is nicely made. The main body of the stem is all carbon – this isn't just a wrap job – and it's well finished in matt black with a shiny logo. The faceplate is aluminium, and the hardware is good quality.
The steerer bolts thread into an alloy insert – you can't put a reliable thread in carbon – and they're not bonded into the stem, so careful you don't lose them if you pull the bolts all the way out.
The stem has a 31.8mm four-bolt clamp and a pretty standard +/- 6° rise, and it's available in 10mm increments from 80mm to 130mm. Slap it on your bike and tighten everything up and it does a fine job. There's plenty of stiffness in the stem, and it'll look the part on any modern road bike. The branding is subtle and the overall performance is good. The only time you'd notice a stem would be if it was doing something bad, but there was no flexing or creaking or any other issues.
Normally, making stuff from carbon means that you can make it lighter for the same performance, if not the same price. Frames, wheel rims, bottle cages, saddle rails, handlebars, cranks... they all tend to follow that rule. Stems are a bit of an outlier really, because the specific twisting forces that they need to counteract are handled so well by a simple metal tube; stick a clamp on each end and you're good to go.
For that reason many of the lightest stems out there are alloy; it's pretty straightforward to make a sub-100g stem out of a more exotic aluminium alloy. Even something mid-range like a £50 Genetic STV stem is lighter for less than half the price (the Prime's RRP is £129.99, but Wiggle is selling it for £89.99).
So if it's a weight saving you're looking for, a carbon stem is a poor route to take. If you're fiddling with your position on the bike, or speccing up a new one, and you're after a nice looking, good value carbon stem to complement your carbon frame and bar and seatpost, there's no reason why the Primavera Carbon stem wouldn't do the job for you.
Make and model: Prime Primavera Carbon Stem
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?
From Wiggle:
"Offering great stability, low-weight and confidence inspiring control, the Primavera Carbon Road Stem completes the ultimate Prime cockpit.
A carbon fibre body and aluminium faceplate provide a superb interface with your handlebars and help reduce hand and upper body fatigue on rough roads, while the carbon construction is torsionally and laterally stiff so it's ultra-efficient as you're zipping into corners or sprinting for the line.
The faceplate is cold-forged aluminum, which provides a highly reliable and strong grip on the handlebar, enhancing your steering.
At just 130g for a 120mm stem, the Primavera will shave precious grams from your race ready machine, rivaling many stems at a much higher price point."
Tell us some more about the technical aspects of the product?
Top Features:
Material: Carbon Fibre
Length: 80, 90, 100, 110, 120, 130mm
Rise: +/- 6
Clamp Diameter: 31.8mm
Steer Tube Clamp Diameter: 28.6mm
Faceplate Material: Aluminium
Face Plate Torque: 5.5Nm
Steerer Tube Torque: 5.5Nm
Weight: 130g (120mm)
Rate the product for quality of construction:
8/10
Nicely made and finished.
Rate the product for performance:
8/10
It does the things stems do, no issues.
Rate the product for durability:
7/10
No problems during testing; it'd be easy to lose a clamp insert which would be difficult to replace.
Rate the product for weight (if applicable)
6/10
It's not heavy but you can get lighter stems for less.
Rate the product for comfort (if applicable)
6/10
Stems don't major on comfort, stiffness is their thing.
Rate the product for value:
7/10
For a full carbon stem, it's pretty cheap.
Tell us how the product performed overall when used for its designed purpose
It's good: stiff and good looking, not expensive.
Tell us what you particularly liked about the product
Nicely made, stiff, good value.
Tell us what you particularly disliked about the product
Not especially light, non-captive clamp inserts would be easy to lose.
How does the price compare to that of similar products in the market, including ones recently tested on road.cc?
For a full carbon stem, it's cheap.
Did you enjoy using the product? Yes inasmuch as you can enjoy a stem.
Would you consider buying the product? Probably not.
Would you recommend the product to a friend? Yes, in the right circumstances.
Use this box to explain your overall score
It's a decent stem, for sure. You can get lighter stems cheaper, but if you like the chunky carbon look then it's a pretty good value way of getting it.
Age: 47 Height: 189cm Weight: 94kg
I usually ride: whatever I'm testing... My best bike is: Kinesis Tripster ATR, Merida Scultura, Dward Design fixed
I've been riding for: Over 20 years I ride: Every day I would class myself as: Experienced
I regularly do the following types of riding: road racing, time trialling, cyclo cross, commuting, touring, club rides, sportives, general fitness riding, fixed/singlespeed, mtb, Mountain Bike Bog Snorkelling, track
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4 comments
It's about the same weight as a good quality alloy stem, BUT - and this is something I've only just realised, having previously been skeptical of carbon stems - I believe there may be advantages to using carbon stems to clamp carbon steerers and bars. It's so common to have alloy stems leave imprints on steerers and bars, which are always a little worrying from a safety perspective. In my (admittedly quite limited) experience, carbon stems seem much less prone to this, partially because the material is the same and partially because they tend to have wider, more encompassing clamp designs with less sharp edges.
looks exactly like the engage ST-06 which is/was the "budget" brand of ax lightness
I've never really got the carbon stem thing, as the review itself states, they're usually no lighter, unless it's designed to integrate with an aero setup then I'm not sure why you'd spend the money. Do you not have to be even more careful about tightening bolts etc with this? Then again each to their own I suppose.
Yep. Unless it's an all in one, integrated jobbie then carbon stems make no sense. Even the pros rarely use carbon stems due to them usually being less stiff.