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The Castelli Sfida 13 Women's Socks offer exceptional comfort and insulation. They will serve you well through a wide range of winter temperatures, too, which goes a fair way to justify their expense.
The Sfida socks are like having a pair of cosy slippers on. They are, by far, the most luxurious winter socks I've worn. They don't offer any kind of compression and are quite thick, though, especially against something like Sportful's Wool Woman 16 socks.
The thick terry footbed is what really sets the Sfidas apart. It does a super job of keeping your feet warm on even the coldest of days, and you really sense the cushioning under the foot. I've even used them without overshoes on cool, dry rides, something I rarely dare to do – I am one for overshoes as soon as the mercury drops into the low teens.
Sweaty feet weren't an issue when I added overshoes, or wore the Sfidas on milder days either. They're a good length, and the ankle area gets an extra layer of protection too.
The merino certainly helps keep odours at bay; I got several wears out of them before they made it into the machine. After that I noticed a very small amount of shrinkage – not enough to affect the fit, though.
The're also showing signs of bobbling at the heel, particularly at the pattern edges. There's no visible thinning though, and the fabric still feels as soft against the foot as on day one. To be fair, I'm sure the bobbling has been aggravated by my off-road shoes, which have a more textured interior.
If the brilliant pink doesn't appeal, they're also available in black and celeste (for £1 less).
They're appropriately priced given that they can deal with a good range of winter temperatures. Those Sportful Wool Woman 16 Socks are £17 as well, and I don't think they offer the same comfort or temperature range as the Sfidas. The recently reviewed M20 Merino Crew Compression Socks are £16.99, and while they aren't female specific they do offer compression.
If you are on a budget, dhb's Aeron Light Weight Merino Sock is an option at £10, or they do Mid and Winter Weight versions for £12 and £15 respectively.
I'd say the performance and comfort of the Sfidas more than justify the price tag, though. You're sure to get plenty of use out of them, right through winter and, without doubt, will love the cosiness. The heel may start to look a bit worn early, but performance seems likely to stay high for a long time.
Warm, breathable and exceptionally cosy – great for most winter days on the bike
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road.cc test report
Make and model: Castelli Sfida 13 Women's Socks
Size tested: Large
Tell us what the product is for
The UK importer says: "The Castelli Sfida 13 Sock is a women's cycling sock designed for the cold. Super warm soft Merino wool is blended with Polyamide and Elastine to create a super snug fast drying and moisture wicking winter-weight cycling sock.
"The foot-bed of the sock is created using a Terry knit this creates a thicker than normal, luxuriously soft feel, but more importantly, it equals great insulation, where you need it most. The cuff extends to a generous 13 cm ensuring full coverage and more than enough sock to provide a decent overlap with your winter tights.
"Sfida translates as challenge dare or defiance, so make a stand defy the cold winter and go ride your bike."
Tell us some more about the technical aspects of the product?
Merino wool blend
Thick terry construction under foot for added warmth
See main body... wear is cosmetic and hasn't affected comfort or performance, yet.
No compression, but no bagginess or wrinkling for me with L/XL. I'm a 42 shoe.
The footbed makes the sock exceptionally comfortable.
How easy is the product to care for? How did it respond to being washed?
Stick it in with the rest of the cycling kit at 30 degrees.
Tell us how the product performed overall when used for its designed purpose
Brilliant, really can't fault them – comfortable and warm without any sign of sweaty feet.
Tell us what you particularly liked about the product
Soft footbed – so cosy.
Tell us what you particularly disliked about the product
Bobbling and a worn look appear very quickly.
How does the price compare to that of similar products in the market, including ones recently tested on road.cc?
Not overpriced given they do cater for all temperatures; most winter ones are around £15. Sportful's Women's Wool 13's are £17, as are M20's (not female specific), making Castelli's look a good investment. You can get cheaper with Madison's Isoler Deep Winter Socks (10.99) or options from dhb between £10 and £15.
Did you enjoy using the product? Yes
Would you consider buying the product? Yes
Would you recommend the product to a friend? Yes
Use this box to explain your overall score
Very good performance and comfort – if they resisted cosmetic wear better, they'd be a nine.
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…