They may lack waterproofing, but Primal's Trimotif Thermal Arm Warmers are warm, soft, well made, and half the price of many. The lack of windproofing is more of an issue, as they're overwhelmed by fast-moving air once temperatures hit the lower single digits.
They certainly stand out in the sea of black that is the marketplace, with a design that's not just bold but substantially different on each arm. Personally I really like it, especially as the fluoro yellow arm works really well to highlight when you're signalling a turn across traffic, but they definitely divide opinion.
Each is a simple tube with a single overlocked seam running the length, and a well-judged stretch to the polyester/spandex fabric gives a slim fit that doesn't bunch at the elbow. A silicone band and wide elastic keep them in place at the top; once they were on, I never found myself adjusting them.
The inside is a pleasantly soft and fleecy brushed finish, which traps warm air well but also deals decently with sweat. On sunny but cool days (around 13-14°C) they remain comfy, and though I often removed them to discover sweaty arms, I never felt uncomfortable while riding.
They're less capable once it's properly cold. They cope down to around 5°C if it's calm and sunny, or your speeds are under 15-20mph. However, if it's overcast, windy or you're spending time at 25mph+ you soon get cold if the air's much below 10°C. They're not in any way draughty, but at speed your warmth steadily drops.
The lack of windproofing is the most limiting factor, far more so than the absence of waterproofing.
Inevitably there's some bulk to them when pocketed too, but they roll to around the size of a cigarette packet so it's not intrusive. Getting them on and off is harder if your arms are damp or wet, but I'll take that small hassle for the slim, secure fit. Primal's size recommendations are accurate, and the Trimotifs come in five sizes.
If the design is really not for you – it's intended to complement the matching jersey, but I was surprised how well they go with random solid colours – it's worth noting that Primal's other warmers appear to be the same product with different names and designs. Many are equally wild (or wilder), but there are simple black or fluoro options too.
For the same price you could have the similarly eye-catching Hackney GT Robi arm warmers, which do a better job of keeping wind out, but explicitly wind and waterproof options tend to be considerably more expensive. Pearl Izumi's Elite Thermal Arm Warmers are twice the price at £40 (minus a penny), but then our reviewer found them 'near-perfect'. Gore's Universal Windstoppers are also £40 (and have been updated since our review).
The Trimotifs are a good price and great on those cool autumn/spring days where it's borderline between bare arms or long sleeves, but if you're looking to extend a summer jersey's use into winter for entire rides, these arm warmers lack the necessary resistance.
Stylish and comfortable arm warmers you'll love on cool autumn/spring days, but not for proper winter
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road.cc test report
Make and model: Primal Trimotif Men's Thermal Arm Warmers
Size tested: Medium
Tell us what the product is for
Primal says: "Primal Arm Warmers and be ready to adapt to rapidly changing climates without the responsibility of hauling a jacket around. These compact warmers roll up to easily stuff in your back pocket."
Assuming those climates are rapidly changing within quite a narrow cool/dry window, it's right.
Tell us some more about the technical aspects of the product?
Primal says, "Primal Arm Warmers are built using Traverso fabric: optimized for freezing temperatures yet versatile enough for up to 75 degrees F. An anatomical design with silicone grippers at the bicep prevent slippage and maintain flexibility. They're adaptable to rapidly changing weather and use less space when rolled and stored in pockets."
Overlocked seam causes zero problems.
Very good in dry and cool conditions, but weak in true cold; I don't believe the 'optimized for freezing temperatures' claim.
Strong stitching and thickish fabric have given no problems.
Comfy and secure.
Recommended size gives a slim and secure fit that's not too tight.
Par for the course for fleecy warmers.
Good price and performance, so long as you accept their autumn/spring window.
How easy is the product to care for? How did it respond to being washed?
Bright yellow sections show grubby marks easily, but they wash up fine.
Tell us how the product performed overall when used for its designed purpose
Great when it's mild/chilly, disappointing when freezing.
Tell us what you particularly liked about the product
Asymmetrical colours look good and boost the visibility of hand signals.
Tell us what you particularly disliked about the product
Slightly awkward to get on and off damp or wet arms; lose heat to cold winds.
How does the price compare to that of similar products in the market, including ones recently tested on road.cc?
Considerably cheaper than most we've tested recently (usually by at least £10), but then they lack waterproofing and/or windproofing.
Did you enjoy using the product? Yes
Would you consider buying the product? Maybe
Would you recommend the product to a friend? With caveats, yes.
Use this box to explain your overall score
These are warm, comfortable, secure and easy to stash away, but properly cold wind overwhelms them, limiting their use to autumn/spring-type days of around 8-15°C. The price is good, but the lack of versatility keeps the score to merely 'good.'
About the tester
I usually ride: GT GTR Series 3 My best bike is:
I've been riding for: 10-20 years I ride: A few times a week I would class myself as: Experienced
I regularly do the following types of riding: general fitness riding, mountain biking