Castelli Flanders Warm baselayer

We've tested the Flanders Warm baselayer, which Castelli claims is just right for Flanders in February




  • Warm and comfortable
  • Does not get wet under exertions
  • A close fit


  • Synthetic fabric collects odours
  • Sizing is a bit out

Price as reviewed:


Castelli claims that its Flanders Warm is designed for conditions in Flanders in February – which will be about what we get here in the UK too. Baselayer garments for proper winter conditions are now often made of merino wool, but Castelli sticks with synthetic for the Flanders Warm, although it’s so soft that you would hardly know it is made of polyester. The fabric is fleeced on the inside surface.

And it is warm. Under a windproof outer it’s comfortable in typical UK winter conditions. This is helped by the high neckline and close fit, with a series of flatlocked seams to ensure that it follows the contours of your body. There’s plenty of stretch, so it will fit most body shapes. Castelli’s sizing is a bit random and I found that I fitted comfortably into a Small. There’s plenty of length too, so there’s good coverage of your lower back and no risk of cold spots. Likewise, the arms are long and I found I got good coverage right down to the wrist.

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Flanders Warm is well finished with a lighter area under the arms

Flanders Warm is well finished with a lighter area under the arms

It’s not a garment which gets too hot though. This is probably helped by the quite large areas of thin mesh under the arms which allow a bit of air circulation and cooling if you start to get hot. And the fabric does not wet out at all, so it is comfortable even if you do work up a sweat.

>>> Oneten merino baselayer review

Where synthetic garments do lose out to wool though is in odour control, and the Flanders Warm is no exception in this. Whereas I could probably – just about – go out for a second ride in a merino baselayer, the Castelli’s synthetic fabric is definitely in need of a wash after each outing.


A quality warm baselayer for cold conditions, although a bit prone to odour


Weight: 140g