Assos Women’s Ultraz Winter LS Skin Layer

The Assos Women's Ultraz Winter LS Skin Layer is top notch in every aspect – fit, comfort, warmth and moisture management, and durability looks to be good too. Its price tag is also on the top notch. But this isn't an everyday baselayer, it's designed for 'your coldest rides' and 'the most challenging winter conditions'. If your riding doesn't stop whatever the weather, the Ultraz is well worth considering.

The Skin Layer is successor to last season's Skinfoil. Assos claims that it's 'about 10% lighter' than the Skinfoil (the non-Ultraz version is 'roughly 13% lighter'). The seamless construction remains the same, but the composition is significantly different, with wool (31%), polyamide and carbon fibre added into the mix – a 'robust arctic-tuned blend' according to Assos.

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The weather has been great for testing over the last few weeks: the Ultraz is at its best in temperatures from 6°C down to freezing on the road – and lower than that if you venture onto trails. It's only when the mercury has approached double figures that I've found it too warm (worn under a jacket I would normally team with a standard polyester baselayer and be 'just right'). That would seem to confirm its 3/3 rating in Assos' Layering System.

The high neck is very snug and really does give the baselayer a winter feel. I found I didn't need to add a neck warmer, as I normally would when riding in figures close to zero. But it does emphasise the Ultraz's 'only cold weather' tag: I found it a little stifling in anything above 8°C.

I haven't suffered with moisture build-up at all, even when working hard – it handles sweat well. Unlike some tops, there's no rapid cooling off or sensing of a damp chill if you stop for any reason mid-ride. Maybe this is the carbon fibre content working. I'd say Castelli's Prosecco Tech layer is as good at handling moisture, but it's nowhere near as warm.

The fabric itself is very giving and soft, hugging the figure without any pinching or irritating. It doesn't offer compression – it's skin tight without being restrictive.

If you use the size guide on the Assos site, it takes into account your height, weight and age. I came up as needing a medium (sizes, S-L, are labelled 0, I and II by Assos) and for me the fit was perfect. I'd say it's worth using Assos' guide too, as the length is important here because it doesn't have a drop at the rear and you don't want to be left short (some online outlets might only use chest measurements).

On me there was just enough length in the body and sleeves. I tested it with both bib and waist tights. The stretch in the fabric means you can easily pull it down to tuck into the waist band of your tights, and I never had an issue with it riding up, though this could depend on your tights.

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I don't tend to suffer with irritation from side seams, so the boast of there not being any didn't cause huge excitement, but I have to say it is noticeably more comfortable than having seams.

The 'circular seamless construction' makes little difference here aesthetically, given you'd be wearing it with a winter jersey or jacket, but I can see it could be useful in the short-sleeved versions also made this way, under a skin-tight short-sleeve jersey. Naturally, there are seams at the base hem, cuffs, neck and shoulders, and they are all very tidy.

One thing worth noting with regards to the seams is that they have plenty of give – some baselayers have seam stitching that doesn't stretch and can pull on panels of fabric, creating weakness at the seam and, worst case scenario, actually snap the threads. There's none of this with the Ultraz.

Care

Instructions are for a 30 degree wash, no softener, so just like most cycling kit. The wool content of the layer is a big plus here – I've been getting several wears out of it before throwing it in the laundry. This is certainly a win over fully synthetic layers that can be smelly after one wear.

Value

There's no denying that the Ultraz Skin Layer is an expensive bit of kit, and you can certainly pay less, even for some high-end options. The GripGrab Freedom Thermal base is one of the closest, boasting a similar seamless construction, for £90, while Rapha's Women's Pro Team Thermal Base is £70.

But Assos sees this as 'the ultimate defensive first layer in the most challenging winter conditions'. If you don't need that, its non-Ultraz version is £85. (And you can spend more – Rapha's Men's Deep Winter Windblock Base Layer is £130, though it does, as the name suggests, have a windproof panel at the front.)

There are plenty of cheaper options for winter training, though. Craft has some great layers – Ashley got on well with the men's version of the Active Intensity CN LS Layer, and there's a similar women's version for £40. dhb's Merino Layer is also an option for £45, and you can go cheaper still with Decathlon's Van Rysel women's base layer for £29.99, which even comes with a two-year warranty.

Conclusion

While I've been bowled over by the performance and quality of the Assos Ultraz, personally I'd struggle to justify the expense, especially given the range of alternatives at much more palatable prices. However, there's no denying it's a very good piece of kit when the weather is raw, and if you like to rack up the miles in some seriously low temperatures, you might consider the investment money well spent.

Verdict

Faultless performance and comfort – but you have to dig deep to pay for it