At road.cc 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.
The One Thermium Jacket from Gore, industry leader in breathable technology, is about as warm as it is lightweight, which is to say: very.
Gore's One range of jackets (including the One Active, tested by Dave Arthur) showcases the very best of what the company can achieve, and for most of us cyclists that means you expect excellent waterproofness teamed with top-of-the-line breathability. Gore has got so good at it – with Gore-Tex a fabric that has been engineered and re-engineered for more than two decades and remained at the top of the tree – that it takes something really special to go elsewhere.
The Thermium is a little different, instead moving towards the lightweight thermal market. Its slim yet accommodating cut hints at a more relaxed focus – commuters and urban riders take note – and more closely resembles a lifestyle jacket than an out-and-out cycling top. Even Gore calls it a 'comfort fit'.
As a result, it got most of its test runs when I was commuting or doing short rides into and back from town, where body heat isn't necessarily generated as much as on training rides, and extra warmth was therefore needed.
In a word, it's absolutely stunning. Last year I reviewed the Castelli Meccanico jacket, and was so impressed with its light weight, warmth and stylish looks that I've hung on to it (for long term testing...) and continued to use it into this winter too. And, although the Thermium can't quite match the scorpion in terms of style, in my eyes – though it's still a good looking jacket – it's got it beat in the performance stakes.
It's super-insulating, while being lighter than the Castelli. It's also lightly water resistant – more so than I found with the Meccanico – and retains Gore's signature breathability, minus a little owing to the extra depth of construction. Unless you go full gas for a while, or ride it in genuinely mild temperatures, you're not going to flummox it.
That construction is key – and gives the Thermium jacket both its name and its qualities. The fabric itself helps to protect the PrimaLoft insulation, and does so by providing a windproof (via Gore's own Windstopper tech), breathable and water resistant barrier to the outside world. Get caught in a shower, and water will bead off very effectively – although a deluge does seriously challenge it.
That said, that's its only real weakness. You get a cut with a long back – ideal for in the saddle – yet a look that's stylish enough to pull off around town, much like Rapha's softshell used to be. Also thrown in are anatomical sleeves and cuffs that stay in place in the saddle, and a hood that will fit under your helmet at a pinch. It's a good one too, and moves around with your head so your visibility isn't compromised.
Elsewhere on the jacket, you'll find two zipped front pockets as well as a small zipped compartment on the right rear, designed for keys, and adjustable Velcro cuffs and a drawstring hem adjustor too.
Perhaps surprisingly, there are no zipped ventilation channels on the sides, but because the fabric is as breathable as it is, and the focus of the jacket is pointed towards insulation and warmth anyway, it's not a huge problem in day-to-day use. The zips are also very good quality, and very easy to use on the go. They incorporate easy-to-pull tassles and a chin guard around the neck.
Styling-wise, you get some small Gore Bike Wear flourishes on the upper arms complete with a reflective strip.
Size-wise, I'm a medium or large. I enjoyed my large test piece, and felt it complemented the cut overall, albeit with a slight bunching in the front when in the saddle. A medium would naturally come up slimmer with less spare fabric.
The only area of difficulty with the Thermium is in its care, where you need to be extra careful to maintain the technical nature of the membranes and the Primaloft insulation. No tumble drying, no ironing, no dry-cleaning – you're limited to delicate or hand washing, and even then need to do it using a delicate technical wash. While it turns around very well, you're going to want to keep washes to a minimum – so I certainly recommend keeping it as clean as humanly possible (mudguards are a must).
Yes, it's an expensive garment at £260, but for that you get a lot of warmth, not much weight and a jacket that is almost as at home off the bike as it is on it. Just take care of it.
A fantastic jacket at a fantastic price – you'll need to get good use out of it
If you're thinking of buying this product using a cashback deal why not use the road.cc Top Cashback page and get some top cashback while helping to support your favourite independent cycling website
road.cc test report
Make and model: Gore Bike Wear One Thermium Jacket
Size tested: Large
Tell us what the jacket 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?
Gore says: "[The Thermium is] an innovation in engineering and technology, made with GORE® THERMIUM™ technology, keeping cyclists reliably warm. No need to pile on layers, thanks to soft, lightweight material that maintains insulation without adding bulk."
Tell us some more about the technical aspects of the jacket?
- Two front zip pockets
- PrimaLoft® Gold Insulation Active
- Hood with integrated headband for perfect fit in movement and additional warmth protection
- GORE® THERMIUM™ Product: protected insulation, warm, windproof, water resistant and breathable
- Adjustable hood
- Wave-shaped cuff for ergonomic wear
- Reflective print on sleeves
- Adjustable cuff
- Zip tags for easy opening
- Front zip
- Zip-underflap and zip-port
- Reflective logo on back
- Reflective logo on sleeve
- Zip pocket on back
It feels delicate due to its light weight, but it's extremely well made.
It's truly brilliant at keeping you warm without weighing you down. And it's breathable.
If not looked after, I suspect the Thermium would start to look very dishevelled. However, treat it well and it should last.
It's classed as water resistant, and is, with water beading off for a limited time – but it's not designed for a full-on rainstorm.
As with pretty much every high-end Gore jacket I've ever used, breathability is very, very good.
A fit best described as "chilled out", it still manages to look stylish and slim on the torso. The cut is ideal for in the saddle too.
I had a large, which came up slightly big – I think I'd have been better off with a medium, although the extra space did mean I could layer up underneath if needed. Swings and roundabouts, really.
I can't imagine being warmer for lighter.
It's also extremely comfortable. For it to get a 10 here I'd personally like a slightly slimmer cut all-round, which I generally find more comfortable, but I'm nit-picking.
You can't win them all; £260 is expensive in anyone's book, no matter how well it performs.
How easy is the jacket to care for? How did it respond to being washed?
Treat with care! Technical washes and hand washing recommended to maintain the Primaloft insulation and membranes.
Tell us how the jacket performed overall when used for its designed purpose
Fantastically, no question.
Tell us what you particularly liked about the jacket
The sheer warmth and light weight beggars belief.
Tell us what you particularly disliked about the jacket
It's a faff to care for, but that's to be expected if I'm honest.
Did you enjoy using the jacket? Yes
Would you consider buying the jacket? For all its wonders and technical ability, it's a little too expensive for what I'd use it for (short range commuting, and, er... that's about it).
Would you recommend the jacket to a friend? Yes, depending on their needs and budget.
Use this box to explain your score
The Thermium is a seriously high-end piece of kit, but I'm just not quite sure it justifies the price tag alongside the use many people might get out of it. Don't get me wrong, if you're honestly going to use it often and care for it, it's a seriously great jacket. Giving it an overall score is therefore tricky – if money is no object and it suits your needs, it's an 8 or 9 (or 10!) on performance, weight, quality... Take that price into account, though, and I can't give it more than 7. Can't go below 7 either, though...
About the tester
I usually ride: Canyon Ultimate CF SL 9.0 SL (2016) My best bike is:
I've been riding for: 5-10 years I ride: Most days I would class myself as: Experienced
I regularly do the following types of riding: time trialling, club rides, sportives, general fitness riding