Summatory's Hermida is a great base layer for keeping you dry and comfortable over summer.
It's made from polypropylene (63%), polyamide (25%) and polyester (12%). Polypropylene sometimes gets a bad press but some of my favourite, most-effective base layers are made from this fabric.
For a start, polypropylene is extremely light. This sleeveless top weighs just 60g. Polypropylene is also hydrophobic - it doesn't wick or absorb moisture. What's the point of that in a base layer? If you have a fibre that does absorb water either on the outer face of the fabric or as a jersey over the top, it'll work with the polypropylene to draw moisture away from your skin. That's what happens here. I've stayed comfortable in this top even when working up a right old sweat on the climbs, and it's dry in no time.
This base feels really soft - silky, even - and it's mega-stretchy so you get the good, close fit that you need for it to work properly. The only seams are on top of the shoulders; the body has been woven as one continuous piece, different knits in different areas, so there are no ridges to bother you.
As for the smell test, the Sumattory puts in a middling performance. It's not one of those tops that reeks offensively as soon as you put it on, but it doesn't resist odours to anything like the extent of merino wool. It's fairly typical of synthetic fibres, I'd say.
The only real issue here is the price. Polypropylene is usually fairly cheap but £42 is a lot to pay for a sleeveless base layer. You can get a polypropylene Gore Bike Wear base layer singlet for £27.99, for example, and some that are considerably cheaper. So, a really good base layer, but pricey.
Lightweight base layer for keeping you dry and comfortable on summer rides, but pricey
road.cc test report
Make and model: Sumattory Hermida base layer
Size tested: Large
Tell us what the product is for, and who it's aimed at. What do the manufacturers say about it? How does that compare to your own feelings about it?
The Hermida Signature Series is named after World Champion cross-country mountain biker Jos Antonio Hermida, but a cycling base layer is a cycling base layer whether you're riding on or off road.
The seamless body is a good feature in a base layer.
Good, close fit and it doesn't get heavy with moisture
Looking good so far. There are virtually no seams to come apart.
Pretty expensive for a polypropylene base layer, to be honest.
Tell us how the product performed overall when used for its designed purpose
Very well. It did its job impressively.
Tell us what you particularly liked about the product
The comfort, especially when working up a sweat
Did you enjoy using the product? Yep
Would you consider buying the product? Expensive, but I still might
Would you recommend the product to a friend? As above
About the tester
Age: 40 Height: 190cm Weight: 74kg
I usually ride: My best bike is:
I've been riding for: Over 20 years I ride: Most days I would class myself as: Expert
I regularly do the following types of riding: time trialling, commuting, sportives, general fitness riding,
Mat has worked for loads of bike magazines over the past 20 years, and been editor of 220 Triathlon and Cycling Plus. He's been road.cc technical editor for seven years, testing bikes, fettling the latest kit, and trying out the most up-to-the-minute clothing. We send him off around the world to get all the news from launches and shows too. He has won his category in Ironman UK 70.3 and finished on the podium in both marathons he has run. Mat is a youthful 45-year-old Cambridge graduate who did a post-grad in magazine journalism, and he is a past winner of the Cycling Media Award for Specialist Online Writer.