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The Castelli Idro 3 Women's Jacket is mostly fantastic – it's light, windproof, waterproof, packable and yet breathable enough to keep on even when the rain stops. The narrow cut of the forearms isn't exactly perfect though, and given the high price of this even against other Shakedry jackets, that's disappointing.
I was keen to get out in the Idro 3. Thankfully, the weather has been 'kind' enough to provide near perfect conditions over the last month - a cocktail of mild to very cold weather, with plenty of showers and bouts of heavy rain. Delightful, if you're a duck. Or you own a jacket made of Gore-Tex's windproof, waterproof wonderstuff, Shakedry.
The last jacket I tested that used it was Rapha's Pro Team Lightweight jacket, over three years ago. Before that Tass tested Gore's own Women's C5 and the C7 'Viz' version, and since all these use the same coveted fabric, detailing and cut will be your main influencing factors.
I tested a medium, selected after checking Castelli's size chart. The fit around my shoulders and torso is spot on and the collar height is well-judged; high enough to feel snug, without being stifling.
Thanks to some stretch in the lower rear panel – it's a new fabric called Topo – well-packed pockets (or excess holiday weight) are easily accommodated. I found both body and arm length spot on too. However, for me the tapering in the forearms is just too aggressive. It feels tight here and doesn't move freely with a thick jersey beneath, while the rest of the jacket does.
For sure I'd be picking Rapha's jacket over Castelli's if I was judging solely on fit.
The cuff detailing sets the Idro 3 apart too, with a gaiter designed to 'integrate' with gloves and add a bit of soft luxury. However, it's a little strange to add something that absorbs water to a jacket designed to repel the stuff. Yes it feels soft, but when wet – say if your gloves don't 'integrate' all the way over it – it turns into a clingy, elasticated wrist band.
I think we've all arrived at the conclusion that Shakedry is the pinnacle of waterproofing, at least for now (assuming you're not looking for something to crash in too often, anyway). Even so, Topo, the new, waffle-textured panel of fabric at the rear, seems to hold off rain just as well.
Consequently any kind of rain, from drizzle to moderate to biblical, is no problem for the Idro 3.
This panel is not attached on the upper edge, which allows it to stretch effectively and gives access to pockets. It may marginally enhance breathability over a solid rear panel – there's an escape channel for heat – but I'm not 100% convinced. I personally didn't find accessing pockets through it easy either, as there's a generous rain-proofing overlap that's difficult to navigate while riding.
I never felt the urge to remove the jacket in between showers – Shakedry doesn't make you boil-in-the-bag to the extent some waterproofs do – which means it works well to keep you warm as well as dry.
The YKK zip is easy to use anyway, certainly more so than Rapha's two-way with its stiff flap. This in itself is a massive pro; no one wants an awkward, fiddly zip in a race against an incoming shower.
Castelli has added some very subtle reflective detailing with a trim along the lower hem and strips down both sleeves. It's hardly Altura Nightvision, but it's a step in the right direction.
It packs away as well as any other. The rear panel adds a little more bulk, but it's barely worth noting.
This jacket is £300, £20 less than the men's Idro 3 that Leon recently tested. As mentioned, other Shakedry options include Gore's C7 for £279.99 (it's had a £30 hike since Tass tested it), or Rapha's Pro Team Lightweight at £220.
It's perfectly reasonable to be put off by all three having a feminine cut, so maybe it's fair to bring 7mesh's £249 Oro into the equation.
I'm not one to shy away from riding in the rain or cold, and as such I'm to happy spend on high-performance, made-to-last kit – that Rapha Pro Team Shakedry is still performing as it did on day one, which averages the cost out to just over £73 per year. For me, the expense of this fabric is justified.
If the Idro 3 manages the same performance that would work out to £100 per year, but as the new Topo fabric is an unknown it's hard to say. Even so, the Rapha isn't being beaten on price. Read that sentence again, it may sound a little odd...
The fit at the forearms is the biggest issue I have with the Idro 3, but this won't be a problem for everyone. While I'm personally not won over by the Idro's new details, they certainly add a degree of functionality that, without doubt, some riders will appreciate.
However, even if there were no fit issues for me, I'd be unlikely to pay an extra £80 for the Idro 3 over Rapha's Shakedry equivalent. Even with Castelli's superior YKK zip, the cuff detail and stretchy panel simply haven't won me over. If only we could custom order these jackets: Rapha's fit, Castelli's zip, Gore's pouch...
It's Shakedry, it genuinely keeps you dry... the narrow forearms won't suit everyone though, and it's very expensive
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road.cc test report
Make and model: Castelli Idro 3 Women's Jacket
Size tested: Medium
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?
Castelli says, 'The Idro 3 Women's Jacket is Castelli's lightest and most packable fully waterproof rain jacket. The Idro 3 weighs 120g (S) and takes up just half a jersey pocket, making it an ideal companion for travelling fast and light through the worst weather conditions.'
Tell us some more about the technical aspects of the jacket?
-lightest and most packable fully waterproof Castelli GORE-TEX jacket
-GORE-TEX SHAKEDRY product technology sheds water yet offers unmatched breathability
-The entire lower back is in GORE-TEX Topo stretch fabric to expand in diameter if you have a few extra winter kilos or full pockets
-Reflective tape on back of both sleeves for high visibility in low-light conditions
-YKK Vislon waterproof zipper slides easily for ventilation adjustments
-Internal wrist gaiter seals wrist and integrates with glove to keep water out
What you hope for if you've forked out £300.
The best possible balance of breathability and waterproofing available at the moment.
The other Shakedry jacket I've tested is still going strong three years down the line, but the Topo fabric is more of an unknown; certainly no issues so far, though.
The best available.
Rear vent may put it marginally ahead of others.
It wasn't perfect for me; the sleeves are too heavily tapered. Beyond that I found it great, and there's room for a thicker jersey without restriction around the torso or shoulders.
True to size.
Fractionally heavier than others, but it's negligible.
Let down by tight fit at forearms.
For me, there are others out there that fit better and put in a comparable performance for less money, which puts this below average.
How easy is the jacket to care for? How did it respond to being washed?
I have simply rinsed off mud splatters with a shower head; it works well enough.
Tell us how the jacket performed overall when used for its designed purpose
First class performance in any condiditions.
Tell us what you particularly liked about the jacket
Waterproof yet with great breathability. Exceptionally easy-to-engage, smooth running zip.
Tell us what you particularly disliked about the jacket
How does the price compare to that of similar products in the market including ones recently tested on road.cc?
This is pricier than other Shakedry jackets – it's £60 more than Gore's C7, and £80 more than Rapha's Pro Team Jacket.
Did you enjoy using the jacket? Yes, who doesn't enjoy staying dry in the rain?
Would you consider buying the jacket? No
Would you recommend the jacket to a friend? Depends on their arms
Use this box to explain your overall score
This gives faultless protection in the rain, wind and cold. I personally find some of the additional detailing unnecessary and the fit around the forearms doesn't suit, but those are subjective issues – they won't bother everyone, and this as an excellent bit of kit.
About the tester
I usually ride: Road My best bike is: Carbon road.
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, touring, club rides, general fitness riding, Getting to grips with off roading too!
Emma’s first encounters with a road bike were in between swimming and running. Soon after competing for GB in the World Age Group Triathlon Championships in Edmonton in 2001 she saw the light and decided to focus on cycling.
After a couple of half decent UK road seasons racing for Leisure Lakes, she went out to Belgium to sample the racing there and spent two years with Lotto-Belisol Ladies team, racing alongside the likes of Sara Carrigan, Grace Verbeke, Rochelle Gilmore and Lizzie Deignan. Emma moved from Lotto-Belisol to Dutch team Redsun, then a new Belgian team of primarily developing riders, where there was less pressure, an opportunity to share her experience and help build a whole new team; a nice way to spend her final years of professional racing.
Since retiring Emma has returned to teaching. When not coercing kids to do maths, she is invariably out on two wheels. In addition to the daily commute, Emma still enjoys getting out on her road bike and having her legs ripped off on the local club rides and chain gangs. She has also developed an addiction to touring, with destinations including Iceland, Georgia and Albania, to mention just a few. There have also been rare sightings of Emma off-road on a mountain bike…