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Clothing Baselayers - Mens

Castelli Core Seamless Base Layer LS

Castelli have offered seamless base layers before, but they weren't quite right. Seamless construction promises stretch and comfort, but most base layers on the market have a nylon and Lycra® mix that feels comfortable when you put it on but then ends up feeling wet when you're actually riding, and you freeze when you stop. The design team worked hard to make this Core Seamless Base Layer keep you warm and dry, thanks to the addition of polypropylene and polyester yarns, while not compromising the stretch comfort of seamless. It appears they have found the sweet spot that also provides a nice level of warmth for cool to cold days.

When you pull the Core Seamless on you can see the various knit zones and structures within the seamless areas. The fabric tech was challenging enough but the process of creating the garment relies on highly technical control of circular knitting machines that can produce the complicated patterns and design. The ability of the fabric to stretch, conform and move without bunching and retaining it's resilience and return requires serious application of both anatomical and technical knowledge. The final seamless work offers all this and more with comfort and surprising warmth for its weight. This base layer is ideal in cool conditions, providing excellent moisture management, and was designed to work well with standard jersey collars and sleeves, keeping the neck line wide and low, and the folded cuffs compact to the skin.


  • LS base layer with seamless build, ideal in cool conditions, providing excellent moisture management
  • Seamless construction means extra comfort
  • Lighter weight on side and back
  • Wide neck opening to fit under short-collared jerseys
  • Super clean finishes and soft overall feel that won't rub when layering
  • 84% polyester / 16% polypropylene yarns provide soft, warm wicking and exceptional stretch fit
  • Suggested temperature range: 39°-61°F
  • Sizes: S/M, L/XL, XXL
  • Color: Black
  • Weight: 120 grams
Mens Shorts, Bibs, Knickers & Tights
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Palm Circumference6-7"7-8"8-9"9-10"
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