I’m a sock guy. I’m particular and I have more than a drawer full of them. At the end of the day, I migrate to the best-of-the-best. More often than not, those best socks are Merino wool. And, when it comes to Merino wool, few manufacturers can top what FITS brings to the table.
FITS Ultra Light Trail Socks:
- Full Contact Fit™
- Dynamic Toe Cup – contours to the shape of your toes
- Heel Lock – super deep heel pocket with ample cross stretch locks the sock on your heel
- Full Contact Cuff – stays in place due to a tighter ankle and looser calf (proper gradience)
- Style Features & Benefits Performance Cut- between a quarter and crew height
- Ultra Light Trail top rises between Quarter and Crew height
- Vented upper and instep for increased breathability and reduced bulk.
- Contents: 50% Merino wool, 40% nylon, 7% polyester and 3% Lycra Spandex
- MSRP: $16.99
My Experience
After a full run-down of FITS socks at Outdoor Retailer, I was impressed. The construction of FITS socks sets the standard for Merino wool sock construction. Now, making socks out of Merino is not an easy task. While Merino offers excellent qualities, durability and ability to maintain shape can sometimes suffer. Getting the right mixture of supporting materials extends comfort and durability. FITS says they take 40% longer to knit their socks compared to other manufacturers — that extra love was evident in my test period.
So far, the Ultra Light Trail socks have held up to repeated use without much washing. Consider this review to be cycling-specific as I’ve worn these exclusively with my Specialized S-Works Road Shoes on hundreds of miles of cycling.
Aside from the excellent construction, my favorite feature is the “Heel Lock” heel pocket. This simple “Y” stich pattern gives a deep and locked-in heel pocket. Your heel sits right in there and never wiggles around — even when slipping into a tight-fitting pair of cycling shoes. This especially comes into play with extended use. Admittedly, I tend to go weeks between washing my road bike socks. They don’t get “dirty” really and these socks have excellent anti-odor properties.

That extended use between washings can sometimes wreak havoc on lesser designs, but The Ultra Light’s have performed like champs. The toebox looks as solid as day one — even after repeated toenail rubbing. Other socks that I’ve mistreated this way have suffered from holes in the big toes — not these.
Even in 90+ degree heat, these socks breathe extremely well. While they call these “ultra light”, there are lighter weight socks on the market, but this is about right for Merino socks. Breathability is enhanced by the vented uppers, which also aid in overall support for a foot-hugging fit.
My foot is a solid 10.5 and I’ve been wearing the size Large.
The Good:
- Heel Lock pocket keeps them in place
- The toebox is super durable — no signs of toenail wear
- Snug fit overall for extra support
- Breathability in high temps is excellent
- Perfect cuff height
The Bad:
- I’d like something just a little thinner
The Bottom Line
FITS is setting a high bar in Merino wool construction with the Ultra Light Trail socks. The tight weave and durability is second-to-none. After repeated wear without washing, these retain their shape better than any sock I’ve tested. The new standard.
Buy Now: Available at Backcountry.com