Gore Bike Wear One Thermium Jacket

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.

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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.

> Buyer's Guide: The best cycling clothing to keep you warm in winter

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.

Verdict

A fantastic jacket at a fantastic price – you'll need to get good use out of it