A sleeveless baselayer is designed to offer maximum comfort on hot days, giving a very breathable layer against the skin to help dissipate sweat as fast as possible. You can spend as much as £50 on a sleeveless mesh baselayer, but for those who baulk at paying that much for something designed not to be seen, the BTwin 500 Warm Weather Mesh Baselayer is a much more affordable choice and it performs very well.
Decathlon's website recommends this as being suitable for a temperate range of 0 to 5 degrees. Happily, we didn't have those sort of temperatures while I've been testing it, and I'd be fairly confident that was a mistake. I've used this in temperatures between about 8 and 30 degrees, and I found it does a solid job of keeping me dry and comfortable.
The fabric used is an open-weave mesh which is highly breathable and comfortable against the skin. Comparing it side-by-side with a similar baselayer from Craft, it is a bit less breathable and less stretchy, but not by a massive amount.
The most obvious difference is in the fit – as the material is a bit less elastic, and the cut is a bit simpler, I found it doesn't sit as smoothly against my torso, tending to hang a little loose beneath the arms. Ideally, a baselayer wants to be skin-tight, although it's only fair to point out that this is probably a size bigger than I'd ideally choose.
Another difference is the use of non flatlocked seams. Against the skin it's good to have as few sources of irritation as possible, and that's why more expensive baselayers tend to have flat seams. Thing is, I wore this for a number of rides both long and short and I can't honestly say I was ever bothered by the seams.
In short, it's not a match for £40 or £50 baselayers, but it does a really excellent job for a rock-bottom price. I think this is where my money would go.
Bargain summer baselayer offers good comfort and breathability, but fit is less refined than more expensive alternatives
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road.cc test report
Make and model: BTwin 500 Sleeveless Cycling Baselayer
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?
Decathlon says: "This men's, sleeveless, cycling base layer keeps you dry in any conditions. Ultra-lightweight and pleasant to wear, it's the perfect base to wear when cycling in hot weather."
Fairly simple cut and construction, as you might expect at this price, but the fabric is comfortable and does a reasonable job of removing sweat.
Better than I expected. It isn't on a par with baselayers from the likes of Craft or Castelli, but it's thoroughly respectable at this price point.
No obvious weak points. Stitching not as neat as some I've seen, so this could be a weak point, but it didn't cause problems while testing.
This is arguably the area where you can most clearly see the difference between this and a baselayer costing £30. The cut is less complex and the fabric less stretchy, so it hangs a bit loose under my arms.
I've got a large and that is probably sized for bigger chests than mine.
Weighs very little.
Pretty good really for the money. There aren't flatlock seams but this simply didn't bother me, even on longer rides.
Cracking value from Decathlon here.
How easy is the product to care for? How did it respond to being washed?
Couldn't find any washing instructions but it seems to cope fine with a 40-degree cycle.
Tell us how the product performed overall when used for its designed purpose
It's 80% as good as a £30 baselayer I'd say, which ain't bad at all.
Tell us what you particularly liked about the product
Breathable, comfortable and cheap as chips.
Tell us what you particularly disliked about the product
Not a lot. The fit is a little less refined than more pricey baselayers.
Did you enjoy using the product? Yes
Would you consider buying the product? Definitely
Would you recommend the product to a friend? Yes
Use this box to explain your score
For the money, this is a cracker. At this end of the market, value is a key consideration, and this offers banging value paired with decent performance. What's not to like?
About the tester
I usually ride: On-one Bish Bash Bosh My best bike is: Rose X-Lite CRS
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: road racing, time trialling, cyclo-cross, commuting, touring, club rides, sportives, general fitness riding, fixed/singlespeed, mountain biking
Jez spends his days making robots that drive cars but is happiest when on two wheels. His roots are in mountain biking but he spends more time nowadays on the road, occasionally racing but more often just riding.