Like this site? Help us to make it better.


Primal Onyx Thermal Bib Knickers



Warm mid-length bibs that put in a solid performance in spring and autumn conditions

At every product is thoroughly tested for as long as it takes to get a proper insight into how well it works. Our reviewers are experienced cyclists that we trust to be objective. While we strive to ensure that opinions expressed are backed up by facts, reviews are by their nature an informed opinion, not a definitive verdict. We don't intentionally try to break anything (except locks) but we do try to look for weak points in any design. The overall score is not just an average of the other scores: it reflects both a product's function and value – with value determined by how a product compares with items of similar spec, quality, and price.

Good scores are more common than bad, because fortunately good products are more common than bad.

  • Exceptional
  • Excellent
  • Very Good
  • Good
  • Quite good
  • Average
  • Not so good
  • Poor
  • Bad
  • Appalling

Primal's Onyx Thermal Bib Knickers are a warm option for middling temperatures, and they come with a decent seatpad that's comfortable without being too bulky. You'll get plenty of use from them on spring and autumn rides.

> Buy these online here

Let's start with the seatpad, seeing as I've already mentioned it. The APX chamois is made up of three layers of foam. It doesn't offer the greatest level of cushioning ever – I'd prefer a little more in the perineum area – but it moves with your body as you pedal, deals with sweat effectively, and there are no savage seams to make you sore. It's not the most high tech chamois on the planet but it compares well with pads you'll find on similarly priced bibs.

Primal Onyx Bib Knickers - pad.jpg

The Onyx Knickers – I prefer to call them three-quarters, personally... you know, to avoid any confusion – are made from a polyester/spandex fabric called Traverso. It's a mid-weight (245gsm), brush-backed, Roubaix-type material similar to that of many winter bib tights, and it offers plenty of warmth. The multi-panel construction makes for a good fit without any tightness, and you can easily arrange the legs so that no seams rub behind your knees as you pedal, which is something that drives everyone nuts. Elasticated grippers with a silicone band hold the ends of the legs in place comfortably. I never found them riding up in use.

Primal Onyx Bib Knickers - back.jpg

I've been using these on days when it's too warm for tights and there's no chance of me wanting to get my knees out mid-ride. We're all different but for me that's a typical spring and autumn scenario.

Primal Onyx Bib Knickers.jpg

The bib section is made from Promesh which, it won't surprise you to learn, is a lightweight mesh fabric. It shifts sweat well without retaining much moisture. The straps are plenty wide enough to avoid any noticeable pressure on your shoulders.

Primal Onyx Bib Knickers - straps front.jpg
Primal Onyx Bib Knickers - straps back.jpg

You get just a small amount of print to break up the black: the Primal name down the side of the right leg and a logo at the bottom of each leg. Oh, and there's a little reflective 'Primal' at the base of the back, although I found that it would sometimes get covered up, depending on the length of the jersey or jacket I was using.

> Buyer's Guide: The best arm and leg warmers

All-round, I found these to put in a solid performance. They're not feature-packed but they do a relatively straightforward job well and they're very good value.


Warm mid-length bibs that put in a solid performance in spring and autumn conditions

If you're thinking of buying this product using a cashback deal why not use the Top Cashback page and get some top cashback while helping to support your favourite independent cycling website test report

Make and model: Primal Onyx Thermal Bib Knickers

Size tested: Medium

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?

Primal says, "With an innovative multi-panel design and thermal brushed back fabric, the Onyx Bib Knickers are designed to optimize performance and keep you comfortable in cool weather. These knickers also have a top of the line APX chamois with 3 density foam layers to ensure your comfort and remove the need to wear additional layers."

Tell us some more about the technical aspects of the product?

Primal says this about the Traverso fabric: "Optimised for damage-free use in warmers and tights while in conditions that are tougher than Calculus, Traverso is constructed with a mechanically brushed back fabric, and traverses excellently between a span of 20-75 degrees F (7-24°C). Reduction of 'grin-through' is thoroughly maintained by a dyed black back that covers the white base once the material is stretched. Many folks may confuse grin through with the face they put on during another one of their friend's tragic attempts at slam-poetry-not the same.

Technical Specs: 90% Polyester, 10% Spandex | 245 gsm"

I wouldn't be wearing these at 24°C, though. That's high summer in the UK!

Primal says this about the seatpad: "The APX chamois is ideal for teams and competitive road cyclists. Three layers of density foam, 4-way stretch and an anatomical shape allow for optimum comfort while maintaining a free range of motion. Antibacterial Silver Ion and Visigrid fabrics offer superior moisture transport and will not break down over time."

Rate the product for quality of construction:
Rate the product for performance:
Rate the product for durability:
Rate the product for fit:
Rate the product for sizing:

I sometimes take a medium, more often a large. These are medium and there's so much stretch in them that I didn't find it a problem.

Rate the product for comfort:
Rate the product for value:

How easy is the product to care for? How did it respond to being washed?

Easy. It goes in the machine with the rest of your bike clothing and comes out just fine.

Tell us how the product performed overall when used for its designed purpose

It puts in a solid performance.

Tell us what you particularly liked about the product

Good fabric, decent price.

Tell us what you particularly disliked about the product

I would have preferred a little more cushioning through the centre of the pad.

Did you enjoy using the product? Yes

Would you consider buying the product? Maybe

Would you recommend the product to a friend? Yes

Use this box to explain your score

It's 8s across the board so an overall score of 8 covers it.

Overall rating: 8/10

About the tester

Age: 43  Height: 190cm  Weight: 75kg

I usually ride:   My best bike is:

I've been riding for: Over 20 years  I ride: Most days  I would class myself as: Expert

I regularly do the following types of riding: commuting, club rides, sportives, general fitness riding

Mat has been in cycling media since 1996, on titles including BikeRadar, Total Bike, Total Mountain Bike, What Mountain Bike and Mountain Biking UK, and he has been editor of 220 Triathlon and Cycling Plus. Mat has been technical editor for over a decade, testing bikes, fettling the latest kit, and trying out the most up-to-the-minute clothing. We send him off around the world to get all the news from launches and shows too. He has won his category in Ironman UK 70.3 and finished on the podium in both marathons he has run. Mat is a Cambridge graduate who did a post-grad in magazine journalism, and he is a winner of the Cycling Media Award for Specialist Online Writer. Now pushing 50, he's riding road and gravel bikes most days for fun and fitness rather than training for competitions.

Latest Comments