Castelli's Core Mesh Sleeveless base layer might raise an eyebrow from the other half when you pull it on, but the open mesh fabric ensures it keeps you cool and dry on hot days when rides can be ruined by base layers that just can't cope with the sweat.
It's available in short sleeve and sleeveless versions. I have found the sleeveless version is more comfortable with tight-fitting short sleeve jerseys; there's less material to bunch up. As with just about all Castelli clothing, it's on the small side (I tested a medium) but the stretch of the fabric means it's not restrictive at all.
In constructing the Core Mesh base layer, Castelli have paid careful attention to minimising seams, and this manifests itself in absolutely no chafing.
The neck has a soft fabric lining, with a small Castelli scorpion on the neck and red stripe on the left shoulder. They've cut it long as well so there's plenty of overlap when tucked into bib shorts.
Castelli reckon it's good for between 20 and 30°C. UK temperatures have only recently risen into the lower working temperature range, where I can confirm the base layer lives up to the high expectations I had for it. I've been using it happily well below the minimum stated temperature range; anything from 10°C up has proved to be just fine.
And on those hot days, the base layer never becomes heavily saturated with sweat, so you stay dry even when riding hard. The open mesh just lets sweat moisture pass cleanly through to the next layer to be evaporated away.
The Castelli's Core Mesh Sleeveless base layer works exceptionally well on the bike, and the best thing is that it doesn't even cost that much. Look at the road.cc base layer review archive (road.cc/review-archive?tid=9739), it's clear that £30 is about average for a high quality base layer. If you're looking for a comfortable and hard-working summer base layer, this is a very good candidate for your money.
A comfortable sweat-wicking base layer ideal for hot days.
road.cc test report
Make and model: Castelli Core Mesh Sleeveless baselayer
Size tested: n/a
Tell us what the product 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?
This is the perfect minimalist piece to keep you cool in warm weather. The fully open mesh serves mainly to hold the jersey off the skin, creating a layer of air between your skin and the jersey to help you maintain a constant body temperature. The fabric absorbs practically no moisture, and it weighs next to nothing so it won't weigh you down.
Tell us some more about the technical aspects of the product?
Fully open mesh creates a layer of air between your skin and jersey
Body wrap design wicks away moisture
Minimal seams for maximum comfort
Cut long to stay tucked in shorts
Soft and stretchy fabric is comfortable next to the skin, and it's very light.
The open mesh design keeps you very dry and sweat-free.
So far, so good.
You barely notice it under a jersey, invisible performance.
£30 is about average for a decent base layer, and to get one with the Castelli logo on at this price is very good.
Tell us how the product performed overall when used for its designed purpose
You've got to start with a decent base layer and this is every bit as good as the best.
Tell us what you particularly liked about the product
Fit and comfort and sweat wicking performance.
Tell us what you particularly disliked about the product
Could do without the labels inside, but five seconds with the scissors fixed that.
Did you enjoy using the product? Yes
Would you consider buying the product? Yes
Would you recommend the product to a friend? Yes
About the tester
I usually ride: My best bike is:
I've been riding for: 10-20 years I ride: Every day I would class myself as: Expert
I regularly do the following types of riding: road racing, time trialling, cyclo cross, commuting, touring, mtb,