Bike Perfect Verdict
With really good wicking and just enough loft to have a noticeable thermal benefit, the Chrono Base Layer is all about dry warmth and comfort… though it’s not cheap.
Pros
- +
Super-dry
- +
Snug, well-articulated fit
- +
Super-soft and comfortable
Cons
- -
Premium price
Why trust BikePerfect Our cycling experts have decades of testing experience. We\'ll always share our unbiased opinions on bikes and gear. Find out more about how we test.
Giro’s Chrono base is a nice reminder that no matter how performant a piece of kit might be, it’s not going to get a look in unless you want to use it in the first place. So a winter base layer might be impressively warm and dry, but if it’s a bit loose or tight, or short or funny looking, most days it’s not going to leap out of the kit drawer unless I *really* need that performance or everything else is in the wash.
I’m going to sound like a bit of a fanboy here but the Chrono Base is so soft and stretchy and decent looking that you're glad to wear it any time. And it backs up its comfort from the cupboard with good unobtrusive performance out on the winter trail. It’s a deserved best buy in our guide to the best winter base layers.
Design and specifications
The Chrono Base has a very lightly brushed inner face, to trap a little warm air and increase the surface area that can draw sweat off the skin. Its fabric is made from 60 per cent nylon (light and soft and decent at wicking), 30 per cent polypropylene (which can be very good at wicking, durable and very non absorbent, but a bit rough by itself), and 10 per cent elastane for stretch.
The fabric has different textures in different places; lightly ribbed in the back, the top of the sides and under arms for articulation; and patterned with slightly more breathable pinholes on the front and where you tuck it in. The main body is seamless, and the shoulder seams are flatlocked and cut diagonally, again to help with fit and articulation.
At 102g, it’s actually one of the lighter winter bases on test, belying its cosy feel.
Performance
I wore the Chrono base in temperatures from mid teens (centigrade) with a thin loose jersey on top, through high single digits with a slightly thicker layer or light jacket and arm warmers, to low single digits as part of a heftier layering system. In other words, for what you’d see from September through April. It was light and breathable enough that it released excess heat if you had a zipped layer on top. But cosy enough that it felt like a good starting point even towards freezing.
Sometimes soft or brushed fabrics can hold on to moisture and end up clammy, but the Chrono base did a great job of staying dry; it didn’t feel like a compromise at all.
In terms of fit, at 5ft8 with a 36in chest I was at the upper end of the XS/S size (33-37in) and it fitted perfectly for body length and articulation around the shoulders. I’m a big fan of the diagonal ‘raglan’ shoulder seam cut; you end up with a really smooth close fit over the top of the shoulder and down the arm, and under the arm too, and I liked the longish cut of the sleeves. The super stretchiness meant it was 100 per cent in contact with the skin across the body, which really helps wicking and for heat retention, though if you’re much bigger you’d want to go up a size; I would have found the fit a bit too noticeable when breathing if it was any more snug.
Verdict
The Chrono Base is priced at the luxury end of things (or the Christmas present end of things), but chances are it would see a lot of use if you had one. It works nicely through autumn, winter and spring, and it’s an easy base to reach for. Like any flat-woven top, it won’t dump heat as fast as an old-school string-mesh base, but that’s the only criticism I have.
Tech specs: Giro Chrono Short-Sleeve Base Layer
- Price: $70.00 / £49.99 / €60.00
- Colors: Men’s: Black, White; Women’s: Charcoal
- Weight: 102g (XS/S)
- Sizes: Men’s XS/S (tested); M/L, XL/2XL; Women’s 2XS/XS, S/M, XL/2XL
- Materials: 60% nylon, 30% polypropylene, 10% elastane
