The Castelli Climber's Jersey 2.0 is a favourite here at Saddleback – content editor Tom took on the Wiggle Bournemouth Sportive to find out what makes it so special

You might not think you need a super airy, super lightweight jersey for UK conditions, but even over the British summer, the Castelli Climber's Jersey 2.0 has become my favourite in the Italian brand's line-up.

The Climber's Jersey 2.0 was designed for hot and mountainous Grand Tour stages – something easily achieved by a brand with Castelli's expertise. Two fabrics are used to keep weight down and breathability high. The Flusso 3D fabric on the front and shoulders weighs just 75g per square metre while the Strada Pro 3D fabric on the back better supports the three rear pockets and offers UPF 16 protection from the sun.

Castelli's real masterstroke though, is in choosing similar patterning to the Aero Race 5.1 – the fastest jersey the brand has ever produced. In mimicking that jersey's skin-tight racing cut with the Climber's Jersey 2.0, the brand created an aero saving of 18 watts at 40km/h compared to a standard jersey, just four watts off the AR 5.1.

The result is a stunning combination of aerodynamics and airiness that makes it, for me, the ultimate jersey on a warm day. As someone who gets a sweat on from almost the first pedal stroke, anytime the mercury creeps up past 15°C, or pretty much anytime it's sunny when I look out the window before a ride, out comes the Climber's Jersey 2.0.

With a fast, rolling course and temperatures in the 18 to 22°C range at the recent Wiggle Bournemouth Sportive, the event was the perfect opportunity to make the most of the jersey.

Having happily worn the CJ 2.0 without a baselayer previously, and not being the most hirsute, I felt no qualms about donning it for this event despite its vaguely see-through front. In fact, it's the cooling effect of that front that I was after.

Setting out, the breeze on my chest told me immediately that I'd made the right decision. The cooling effect was really noticeable as we set out on a fast section, enough to keep the zip all the way up to the collar without wishing I had more airflow. This could actually make the jersey faster than the Aero Race in real world conditions, where riding with a zip down is preferable for many to maintain comfort over 100 miles of riding.

In fact, the only time the zip did come down was on the climbs where any aero advantage is wiped away in the face of cadence-down-to-50 gradients. In those situations, it was the zip itself that excelled – the lightweight design's smooth running ensuring simple, reliable and instant one-handed operation.

While we're on the subject of practicality, the rear pockets behaved just as they should – without sagging and holding gels and spares securely – while the reflective detailing is a welcome bonus.

The jersey is also an expert when it comes to wicking. Despite the heat, hills and miles, it never got saturated and was almost instantly dry after every hard climbing effort and even when dousing aching neck and shoulders with water. On top of that, I was without doubt faster with the Climber's Jersey 2.0 than flappier types in my collection, the aero cut doing its job as I kept the average on-par for my first gold-ranked finish in a sportive.

So it's nice and cool and extremely aero, but all that counts for little if the jersey's uncomfortable. Including a 10-mile spin to and from the event location, I covered 120 miles with absolutely no chafing, annoying seams or other irritations – comfort was nothing short of superb. But what else would you expect from Castelli?