The Castelli A/C 18 Sock is a very good hot weather option. It’s lightweight, breathable and comfortable, and the price is broadly in line with similar options.
The construction is 96% nylon and 4% elastane, which makes for a sock you barely notice once it’s on.
The ribbed texture keeps it in place without feeling tight, and the fit stays consistent throughout a ride without bunching or slipping.
I wore these during a heat wave and my feet stayed comfortable throughout. (Well, as comfortable as you can be in 32 degrees.)
The cuff length gives a race-style look without going so high that you look ridiculous, and the Castelli logo is small enough that it doesn’t dominate. As you’d expect for this price, they’ve also held their shape well after repeated washing.
The A/C 18s aren’t the cheapest option out there, but they’re reasonable value for what you get.
A couple of years ago, I tested the Rapha Pro Team socks and they are remarkably similar in construction and performance, and even come in at the same price.
You could also look at the Pas Normal Studios Solitude Socks which are a couple of quid cheaper and again offer similar performance in the heat.
There isn’t a great deal more to say. They’re socks, they fit well, they keep your feet cool and do everything you want without any fuss.
> Best cycling socks — treat your feet and turn up the style on your bike rides
Test Report
What does the manufacturer say about this product?:
Reach for the Castelli A/C 18 Socks when summer temperatures are at their highest. The ultralight construction means you’ll barely register the socks are there and also ensures extreme breathability to keep overheating at bay. Despite their low weight, the nylon construction is also made for durability. An 18cm cuff provides extra coverage above the ankle and a small Castelli wordmark logo gives a stylish and subtle finish.
Tell us some more about the technical aspects of this product:
Ultralightweight construction for the hottest days
Highly breathable and durable nylon threads
Ribbed texture for the perfect mix of lightness and durability
Castelli wordmark on cuff
95% polyamide, 5% elastane
18cm cuff
How does the price compare to that of similar products in the market, including ones recently tested?:
A similar price to similar products.
Did you enjoy using the product? Yes
Would you consider buying the product? Yes
Would you recommend the product to a friend? Yes
Use this box to explain your overall score
They work very well in heat and they’re comfortable, but they’re expensive.
About the tester
Age: 38Height: 182cmWeight: kg
I usually ride: Orro VenturiMy best bike is: Specialized Diverge
I’ve been riding for: 10-20 yearsI ride: A few times a weekI would class myself as: Expert
I regularly do the following types of riding: Gravel riding, Commuting, Club riding, Sportives, Fitness riding, Leisure riding
