dhb's Aeron Merino Base Layer is priced at the lower end of the baselayer spectrum, but given it's only 65% merino and suffers from fit shortcomings, it's not one I'd rush to buy.
To my mind, baselayers really only have to do two things – fit snugly and feel nice. In the fit stakes, use of stretchy fabric should make covering a varied populus easy enough, and modern synthetic and natural fibres have rendered feeling sweaty or itchy pretty much to the bargain-bin of history. It's against this ever-higher bar of fit and performance that the Aeron baselayer is measured – and for me it comes up short, literally and figuratively.
In the medium size, the sleeves aren't quite long enough, though I do have arms 2in longer than the norm for my height of 6ft, so if you are of normal proportions you should be OK. There's no sort of thumb loop or elasticated wrist, so you do need to get the length right or risk a draughty cuff.
dhb's 'Performance' size guide has me being a small in waist and chest but large in hip, which is bizarre as the medium felt pretty snug around the shoulders and chest, and with the short sleeves I'd err towards a large. Keep that receipt and use Wiggle's returns policy wisely. (I'd also like to point out that a medium dhb Classic Roubaix Long Sleeve Jersey I've been testing – review to come – which is likewise in the 'Performance' fit range, fitted me perfectly.)
Another point to note is the rear hem length: it's level with the front, so when bent over on the bike you risk a draughty back if your bibs don't come up high enough to cover the gap. From a cycling-specific brand like dhb this is a surprising omission.
The merino/polyester mix didn't feel as nice as pure merino baselayers I own – a little scratchy, to be honest. Once riding and warmed up I didn't notice anything out of the ordinary, riding slow or at actual race-pace now the cyclo-cross season is upon us. The '37.5' technology involves a coating added to the fibres, to increase the surface area and therefore evaporation of sweat. In practice it's near-impossible to quantify the benefits unless you create a Frankenlayer of the same fabric that's half-37.5, half normal, but what I can say is that it felt much the same as other decent-quality baselayers in terms of moisture transfer.
So all-in-all, a mixed-fabric-feature bag. If it fits you, the price can't be sneezed at.
Good value if it suits your shape, but not especially soft against the skin or the best cut for cycling
road.cc test report
Make and model: dhb Aeron Merino Base Layer
Size tested: Medium
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?
dhb says: "Super soft and warm the dhb Aeron Merino Base Layer utilises the natural properties of merino wool so you remain warm when it's cold and cooler when warm. Natural odour resistance also keeps you fresh all day."
Tell us some more about the technical aspects of the product?
65% Merino Wool
Top Features of the dhb Aeron Merino Base Layer (M_37.5)
The ultimate, high performance merino wool base layer with 37.5 technology
Superfine merino wool provides outstanding thermal regulation, odour resistance and breathability
37.5 technology greatly increases moisture transfer and increased durability
160g/m2 fabric weight
Stretch fit sits close to the body
Abrasion free flatlocked seams
Australian wool from a guaranteed non-mulesed source
Flatlocked seams and good quality fabric stitching.
Average ability to wick sweat.
Washed well with no signs of duress.
A let-down – quite out of sorts.
Again, sizing is very erratic.
I've worn many more comfortable baselayers.
Questionable, but OK value if it fits.
How easy is the product to care for? How did it respond to being washed?
Well – no signs of wear.
Tell us how the product performed overall when used for its designed purpose
Average, not bad but not great.
Tell us what you particularly liked about the product
Nothing in particular.
Tell us what you particularly disliked about the product
The fit – definitely odd.
Did you enjoy using the product? Not really.
Would you consider buying the product? No
Would you recommend the product to a friend? If they were correctly proportioned to fit it, yes.
Use this box to explain your score
Given I've never come across a baselayer that caused me so many concerns, I can't rate it highly. But if it fits you, the price is good.
About the tester
I usually ride: Merida Ride 5000 Disc My best bike is:
I've been riding for: Over 20 years I ride: A few times a week I would class myself as: Expert
I regularly do the following types of riding: cyclo-cross, club rides, general fitness riding, mountain biking, Dutch bike pootling