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Code: CS17508
Castelli Alpha Ros Light Cycling Jacket - AW19

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 temps when you may have worn arm warmers and a vest in the past. We call this functional waterproofing because while we don’t guarantee that no drop will ever enter the jacket, we promise you that this is our best effort to keep you warm and dry in the widest range of conditions.

RoS stands for Rain or Shine. It’s a label Castelli give to 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 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.


  • 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:380g

Sizing Information for Castelli Clothing:

Castelli Size Charts

Andrew A Brilliant piece of kit - been wearing it in temperatures lower than recommended and found it both warm and comfortable - really great jacket
Mr Moore Great piece of kit, does what it says. Order at least a size up with castelli as they come up small.
Taejin This is one of the most versatile cycling jacket that I own. It is breathable and warm and waterproof. Highly recommended.
GMP Well done Castelli & Merlin. This is a great piece of kit at a cracking price. Worn 1st time on a just above freezing in the Scottish Highlands, performed above expectations with only a merino long sleeve baselayer.
Mr Wood I have been impressed with the quality of the jacket having bought it based on good reviews. I have used it down to 6 degrees with a base layer and it is kept me comfortably warm. I am 6’1 and 14 stone and the 2XXL was the right size choice. Not used in the rain yet but expect it to perform to high standards. Great jacket.
Mr Lin very good quality and comfortable while riding. also stylish. I bought M according to the size chart but It's a bit tight, so you may want to size up.
Mr THOMPSON Standard Castelli! Great piece of kit. Have worn it out in 3/4 degrees and with a good base layer stayed warm. Not hot or cold just warm... As it should be! Makes cycling this time of year fun.
Mr keyes Believe the hype!! Very light jacket but no issues with warmth just wearing one baselayer from 2-7 degrees, can overheat if it gets any warmer on climbs. Been in a few showers, no problem at all. very well made, race fit. I'm 5 8 and 68kgs, small fits perfectly. Bought at amazing price, fresh in orange, will be worn throughout winter.
Claudio Great cool weather jacket. Inner can be unzipped on warmer days. Have used in range 6 to 12 degC on fast rides and have no complaints.
Dr Downer Excellent product for long rides on those mixed weather mornings where it starts cold and warms up.
Gabor from Budapest The same beautiful quality garment than the deep-winter Alpha ROS Jacket. The construction is the same, only the polar inner jacket is thinner. Love for the first sight :-)
Alyosha The best jacket money can buy. A little on the small side.