Sportful’s R&D range includes the Italian brand’s most forward-thinking products, including the likes of the jersey/gilet Strato we included in the RCUK 100 and this, the R&D Celsius summer jersey. With the Celsius, Sportful aimed to ‘create a jersey that functions well in a broad temperature range’ and it does a surprisingly good job of adding a little warmth on cool morning starts while remaining lightweight and breathable when the temperature rises.

There's always a fair amount of marketing hype surrounding the latest and greatest products but we've been rather impressed by the R&D Celsius jersey. Like the Strato, which has a wind resistant fabric incorporated into a conventional winter jersey, the Celsius is designed to cope with variable weather, except this time with a focus on the spring/summer season.

Sportful R&D Celsius Jersey

Price: £110.00

Sizes: XS-XXXL

Size tested: M

Colours: Black/anthracite/red; black

Website: Sportful

As a cyclist, knowing that the temperature will remain consistent over the course of a ride would make life a hell of a lot easier when pulling kit from the drawer, but a lot of the time that's not the case. The Celsius aims to combat fluctuating conditions by adding an open mesh layer to the inside of the jersey. Here’s the spiel, according to Sportful: “The unique construction adds an open inner mesh structure that actually accelerates breathability and moisture transfer by creating next to skin airflow at warmer temperatures. In cooler conditions, warmth is maintained by keeping the skin dry.”

Does it work? Well, the Celsius is unlikely to replace every other jersey in your collection as the ultimate do-it-all summer piece, but there’s some sound thinking behind the design that bears out on the road.

Sportful R&D Celsius Jersey

Think of the mesh layer like an integrated (but minimalist) base layer. If there’s a chill in the air, the mesh structure adds a little warmth over a conventional summer jersey like Sportful’s BodyFit Evo. It’s not windproof by any stretch, nor will it do the job of a gilet, but on those rides that start out in low double figure to mid-teen temperatures, it traps a warming layer of dry air next to the skin to ensure you can leave that gilet in your back pocket.

"If there’s a chill in the air, the mesh structure adds a little warmth over a conventional summer jersey. When the temperature does rise, the Celsius does a good job at wicking sweat away from the skin"

When the temperature does rise, the jersey does a good job at wicking sweat away from the skin and keeping your core dry. While we’d still reach for a dedicated super-light jersey like the Sportful BodyFit Light we reviewed recently for scorching summer rides (the mesh construction does a better job at providing consistent airflow), the Celsius is a good option for when you want to maintain a steady temperature through the course of a ride in less sultry conditions. I've used the Celsius on a range of outings, most recently during the Maratona dles Dolomites gran fondo in Italy, and it's coped admirably.

Sportful R&D Celsius Jersey

During the Maratona, I was warm enough to roll off the start without a jacket or arm warmers (the temperature was in the early teens and the road - and mercury - soon climbed) and didn't need to put anything else on throughout the ride, despite some fairly long and shady descents early on. With the temperature topping out at around 26 degrees, I wouldn't have wanted it to be any warmer before instead opting for a lighter jersey (things got quite toasty under the midday sun on later climbs, so I rode with the jersey fully unzipped), but the Celsius otherwise handled the demands of the ride well.

The mesh panels only feature on the front of the jersey, either side of the full-length zip. The rest of the Celsius is made from a stretch-woven polyester fabric, with a high-wicking fabric on the back (again, that helps with temperature and moisture control) and all in all, the jersey has a quality construction.

Sportful R&D Celsius Jersey

The fit is excellent, too. The R&D Celsius has a race cut, so it may not suit all body shapes, but it’s close in all the right place, with no unwanted bunching of material on the front of the jersey. The neck also sits low enough to avoid irritation, while the elasticated waist holds everything in place and the laser-cut sleeves provide a smooth, fuss-free transition between the jersey and your arms. However, there’s not a great deal of stretch here - to put on arm warmers midway through a spring ride, I had to take the jersey off completely, which isn't ideal. Otherwise, out back there are three rear pockets, but no zipped pocket.

Conclusion

The Sportful R&D Celsius is an interesting take on the summer jersey and works well in the kind of fluctuating temperatures we often see here in the UK. While there are better options for kind of truly hot weather we've experienced of late, the Celsius does bring a novel and effective design to the party, with the unique construction working well on rides that start a little cool and warm up. Visually, we think it’s a real winner, too - but there’s also a black version for more subtle tastes.

Pros

- Versatile jersey for fluctuating spring/summer temperatures
- Excellent race-cut fit
- Bold design stands out from the crowd

Cons

- Restrictive sleeves when putting arm warmers on
- No zipped pocket
- Better options out there for the hottest conditions