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BTwin 500 Sleeveless Cycling Baselayer



Bargain summer baselayer offers good comfort and breathability, but fit is less refined than more expensive alternatives

At every product is thoroughly tested for as long as it takes to get a proper insight into how well it works. Our reviewers are experienced cyclists that we trust to be objective. While we strive to ensure that opinions expressed are backed up by facts, reviews are by their nature an informed opinion, not a definitive verdict. We don't intentionally try to break anything (except locks) but we do try to look for weak points in any design. The overall score is not just an average of the other scores: it reflects both a product's function and value – with value determined by how a product compares with items of similar spec, quality, and price.

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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.

> Find your nearest Decathlon store here

> Buy this online here

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.

BTwin 500 Sleeveless Cycling Baselayer - chest detail.jpg

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.

> Read our guide to the best baselayers

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 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."

Rate the product for quality of construction:

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.

Rate the product for performance:

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.

Rate the product for durability:

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.

Rate the product for fit:

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.

Rate the product for sizing:

I've got a large and that is probably sized for bigger chests than mine.

Rate the product for weight:

Weighs very little.

Rate the product for comfort:

Pretty good really for the money. There aren't flatlock seams but this simply didn't bother me, even on longer rides.

Rate the product for value:

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?

Overall rating: 8/10

About the tester

Age: 37  Height: 188cm  Weight: 78kg

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. 

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Dicklexic | 7 years ago

Bought one in a clearance sale at Christmas for £5. Used a few times over the last few weeks and been very happy. Even at full price it's a bargain compared to Castelli/Craft etc. I've only ever used baselayers in cooler/cold weather before so wasn't sure if it was necessary. Yesterday was quite a hot ride (20-23 degrees) and I think it helped to maintain a comfortable temperature. I also found it stopped a chill when descending with the jersey unzipped a little, but still helped me keep cool. Will be interesting to try it on a really hot day.

Dnnnnnn | 7 years ago

"for those who baulk at paying that much for something designed not to be seen"

If true, says a lot about some of our priorities!

mtbtomo | 7 years ago
1 like

I think I actually paid 5.99 for mine. No issues with fit for me but I probably just haven't noticed. Which is a good sign  1

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