Product Review: Castelli Free 9 Socks

Socks are highly underrated.  They are one of those essential cycling items that can be the difference between an epic ride and and epic fail.  Think about the importance of the cycling sock this way: there are five places on your body where skin meets bicycle — right hand, left hand, butt, right foot, and left foot — and two of those places are covered by socks.  Understand the importance of socks now?  We all know the discomfort and damage a crappy chamois or ill-fitting cycling gloves can cause.  Similarly, a pair of poor quality, badly designed cycling socks can create pain and suffering so great that an afflicted cyclist may consider stopping on the side of the road, taking off his or her shoes and socks, and throwing them into the bushes.  We don’t want that.  So, with the hope of saving our cycling sisters and brothers from the curse of bad cycling socks, we humbly submit the following review of Castelli’s 2013 Free 9 socks.


Usually, product reviews come in one of two categories: Category 1 – Hate It!; or Category 2 – Love It!  After riding in Castelli’s 2013 Free 9 socks for several weeks in a wide variety of conditions and locales, this product review will have very little of Category1 and lots of Category 2.  The crew tends to prefer lightweight socks with minimal padding, excellent moisture management, plenty of ventillation, and, most importantly, that ultra-dorky-but-oh-so-Euro-cool tall cuff.  Spiffy graphics, coordinating colors, and a fair price point are also a plus.  The Castelli Free 9 socks have all these features and more.

Hold the socks in your hand.  It is like holding a feather.  They weigh practically nothing.  Just for fun, hold a Free 9 sock in one hand and a regular cycling sock made from Coolmax fibers in the other hand.  The Coolmax sock feels heavy, rough, and stiff while the Free 9 sock is light, soft, and supple.  The heaviest part of the sock is the top section of the cuff — a doubled-walled woven elastic strip that firmly (but not too tightly) holds that cuff in place and prevents slippage.  If you are going to wear socks with a 9 cm cuff, you want that cuff to stay put and not collect around your ankle after 15 minutes on the bike.  By wearing the Castelli Free 9 socks, you can be assured of a gorgeous, bike geek, above-the-ankle tan line by mid-season!  Oh yes!

Now, put your hand in the Free 9 sock and spread your fingers. What you will see is the genius that makes these socks work so well: the seamless weave.  Yes, that’s right, a seamless, open weave that shields your skin while wicking moisture away.  Take note of the places where the weave opens for greater ventilation (above the ankle, across the top of the foot, around the top of heel) and closes for more protection against abrasion (across the front of the toes, on the bottom of the ball of the foot and the heel, along the lower inside and outsode of the foot).  Castelli spent some time looking at how a foot interacts with the internal surfaces of a cycling shoe and designed the Free 9 sock accordingly, giving the sock a tighter weave in places where slight movement may affect the foot/shoe interface and creating areas of a more open weave where heat and moisture are generated and airflow is present to facilitate cooling.  For cyclists, dry feet are happy feet.  Considering that the feet are the contact point through which vast amounts of energy and repetitive force are transmitted from the cyclist’s biological engine (the body) to the actuating mechanism (the bicycle), it is imperative that those contact points be kept clean, dry, and cool.  The presence of debris, moisture, and heat foot/shoe interface will quickly result in a catastrophic failure of the engine/mechanism system.  The Free 9 sock protects the skin from abrasion, wicks moisture, and facilitates cooling — essential components of the engine/mechanism system.


The design of the Free 9 socks betrays their Italian heritage.  So, be warned: these socks are flashy. The graphics and colors coordinate perfectly with several lines of Castelli bib shorts, jerseys, and gloves for a complete ‘kit’ look.  Castelli was thinking ahead in designing lines of clothing that are both technically functional and visually appealing.  As cyclists, we need clothing that works well and looks good, too.  How many times have you encountered the cycling ‘fashion nightmare’ riding along in his purple bike shorts, orange/tan/brown jersey, green armwarmers, red/black/green socks, yellow helmet, pink gloves, and black shoes?  For all of us here at, this has happened more times than we care to remember (shudder).  So, thank you Castelli for making the Free 9 socks both supremely functional and incredibly fashionable.


If there was one thing we would ask Castelli to add to the Free 9 sock, it is a black version.  We love mountain biking just as much as road biking and white socks do not work well on trails.  So, a black Free 9 sock with the same features and accent colors as the white version would be great for our off road forays.  Just a thought, Castelli.

In our product reviews, we don’t have a rating system that uses stars, thumbs up, gears, chain links, smiley faces, or any other lame doohickys.  We just tell you what we think about the product after we have had a chance to use it for awhile.  The Castelli Free 9 socks are exemplary in their design, construction, and performance — it is THE cycling sock for 2013.


About The Author


Aaron Hanson (a.k.a The Cap’n) is manager of the Southern California Colavita Regional Amateur Team.  A 25-year veteran of the sport and lifestyle of cycling, Aaron has raced both road and mountain bikes, advocated for bicycle transportation funding and facilities at the city, county, state, and federal levels, planned and facilitated numerous bicycle events, and helped several municipalities and counties create viable bikeway master plans.

Aaron has been honored by IMBA, CORBA, Clif Bar, the City of Los Angeles, the County of Ventura, the City of Simi Valley, the United States House of Representatives, and the United States Senate for his bicycle advocacy work.  He has even won a bike race or two.

Aaron can be contacted via e-mail at:



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