The 100% R-Core X Jersey is a neatly-fitting long sleeve jersey best suited to warm weather. It’s cool, comfortable and it’s really clear how far the brand has gone to save weight. The colour scheme won’t be for everyone, though, and the cuffs can rise.
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The R-Core X is constructed from a mix of polyester and elastane mesh paneling, with quick-drying and anti-microbial properties.
Throughout the four-way stretch fabric you find laser-cut venting, which does a great job of maximizing airflow.

At the body and sleeve hems, 100% opts for contrast taping rather than traditional stitching. This saves weight and is also a little bit stretchy, although it’s a bit of a tight squeeze to push your hands through the cuffs.
The fit is slim, but not slim enough to make you want to cut down on the beers. It’s flatteringly tight around the arms though, and not only is this good for the ego but there’s almost no loose fabric to snag on branches or thorns. However, partially due to those taped cuffs, the sleeve can rise a smidge. It’s not world-ending, but if you’re fussy about showing too much wrist it’s something you need to consider.

There’s also a dropped tail that offers more coverage around the back and the trouser line.
Because it’s so light and well vented it’s impressively cool in warm weather, and ideal if you’re against t-shirts. This does mean it’s not the greatest in the winter, despite the long sleeves, but throw on a baselayer underneath and you’re golden.

Aside from the slightly rising cuffs, niggles are few, but I would say the colour schemes are an acquired taste.
If you’re looking for a long sleeve jersey especially for warm weather, the 100% R-Core X jersey is a solid choice. It’s light, cool and it fits really nicely. Just watch out for those rising cuffs.
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