Veste Castelli Idro (Shakedry)

Ultra-packable rain jacket which makes great use of Gore's new fabric and offers very good breathability. Castelli says that the 2-layer Active fabric is the most breathable Gore-Tex ever made, and that is the holy grail of waterproofs – a jacket that keeps the rain out while allowing your sweat to get out too. I've been testing this in the late spring and summer months, when it's tended to be warm. I've worn it on days from around 14°C to the mid-20s. At the cooler end of that scale, the inside stayed dry even on hills, which makes things really comfortable – impressive. Once you're in the 20s, well, that's a tough gig for a hardshell – if you're pushing on, you generate generous warmth and humidity, and that's got to go somewhere. From about 18°C and upwards, I found sweat would build up inside and I'd end up fairly wet unless I was pottering. But in reality, on hot, wet days, a hardshell is arguably not the right choice, and a lightweight DWR jersey is probably a better option. Hot, wet days being not all that common in the UK, there were lots of other days where the Idro hit the spot, and there were more of those days where I had it with me because it packs so small. The lightweight fabric gives it a floaty feel when you put it on dry, and it is a quiet and unobtrusive jacket. The fabric isn't elastic, and so some fairly complex pattern-cutting has been used to ensure a good fit. The cuffs are partially elastic and they stayed in place well, and in fact the sleeves were of a good length such that I never found them flapping around my forearms. Putting the Idro on and taking it off is relatively simple – I could manage it while riding – once I'd got over the initial fear that the thin fabric was going to tear as I yanked it over my hands. A couple of nice touches that were unexpected and welcome on a minimalist jacket. First, there's an angled waterproof zip behind the right hip, which allows access to the right-hand jersey pocket while riding. It's not as easy as reaching round without a jacket on, but it makes grabbing a hasty gel without stopping possible. Also, I liked the well-positioned and sizeable reflective panels on the rear, especially given that the fabric used here is currently only available in black. In conclusion, the Castelli Idro makes very effective use of the new Gore fabric and is comfortable and very nicely fitted. It staunchly keeps the rain outside and does an impressive job of moving moisture out. The biggest selling point for me is how small it packs, meaning that there's no reason not to have it with you. Miraculous, though? Not for me, Clive.