Long Sleeve

Save 24%

Castelli Alpha Ros Light Jacket - Light Black

now £159.00

was £210.00

Why to buy: The Castelli Alpha ROS jersey is their most technical to date, sitting between a light jacket and your warmest jersey and is the perfect weight for cool-weather riding. ROS - Rain or Shine, as it excels in both dry and wet conditions. 


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Available Delivery Options LMSXS
UK Next Day



Castelli call it a light jacket but the comfort range is surprising. It dips well into temperatures where you might normally reach for a full protection jacket, yet the surprising breathability makes it still comfortable in temperatures when you may have worn arm warmers and a vest in the past. And it keeps you dry.

RoS stands for Rain or Shine. It’s a label Castelli give their most advanced products that excel in both dry and wet conditions. For dry conditions, you’re looking for comfort along with breathability to prevent you from getting wet and chilled from the inside. But with wet-weather clothing, you’re looking for protection that will help you stay warm by keeping the rain out and letting sweat escape.

The Alpha RoS W Light Jacket ticks both of those boxes. Both the front and back materials represent a significant step forward in rain protection. These fabrics are used with reduced seaming, and seam sealing where necessary.

Castelli call this functional waterproofing because while they don’t guarantee that no drop will ever enter the jacket, they promise that this is the best effort to keep you warm and dry in the widest range of conditions.

Size Guide

CHEST     WAIST     HIPS       INSEAM    
XS    79CM 63CM 87CM 75CM
S 84CM 68CM 92CM 76CM
M 89CM 73CM 97CM 77CM
L 94CM 78CM 102CM 78CM
XL 99CM 83CM 107CM 79CM

Tech Spec

  • Lightweight double-layer wind jersey with significant rain protection 
  • Windstopper® 150 front and sleeves 
  • Nano Flex Xtra Dry back for the most significant nonmembrane water protection available 
  • ProSecco Strada inner liner with 2nd front zip 
  • Waterproof YKK® Vislon® zipper 
  • Articulated collar that fits better whether you’re standing or riding 
  • Front zippered pocket 
  • 3 rear pockets with reflective laser-cut drain holes 
  • Raw-edge waist lies flat and moves with you 
  • Advanced patterning makes for excellent close-to-body fit
  • Weight: 340g
  • Castelli Comfort range 8-15c

Who's Behind It?

Q. What do a 19th century Italian tailor, a designer for the Milan Ballet and the first ever lycra cycling shorts have in common?

A. They are all part of a rich 140 year history that's led to today's most recognised brand in cycling: Castelli.

Throw in a heart attack on a famous Italian climb, family feuds, Olympic gold medals and controversy in the pro peloton and it begins to sound more like a Sicilian soap opera than the backdrop to a cycling brand. But then again Castelli is no ordinary brand.

Today, Castelli's scorpion emblem is arguably the single most recognised in cycling. Iconic is an overused word these days, but the Castelli brand surely qualifies.

We first discovered Castelli on our year long ride through the Americas in 2010, when our founder Liz (pictured) wore Castelli shorts and loved them, so stocking them seemed an obvious choice. But we're almost as captivated by the story behind the name as the kit itself! For the full Castelli story (it's quite a story!), click here.

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