


Hot
- Warm, breathable and comfortable
- Double-sided silicon gripers keep them in place
- Nano Flex provides flexibility at the elbow
- Plenty long, wrist or upper arm not left exposed
- Unisex
Not
- Run a little small, consider sizing up
Price: $49.99 MSRP
Size: S-XL (unisex)
Color: Black
How obtained: Sample from Company
Availability: Online and retail
RBR Sponsor: No
Add Versatility to Your Cycling Wardrobe
If you don’t have a pair of arm or leg warmers as part of your cycling wardrobe, consider this small investment. Both types of warmers extend the season of your summer kits by giving you the option to add warmth and protection. On cool mornings, slip on a pair of arm warmers, then as the temps improve shed them for stowing in your jersey pocket. Or, if the weather may change mid-ride, take them along and slip them on as needed.
I took the Castelli Nano Flex arm warmers with me on a recent trip to Tucson. If you’ve ridden in the desert you know the mornings are cool, but quickly warms up. Arm warmers were perfect. Ten miles into our rides I could take them off and not overheat. Also, we tried to pack lite for the flight, so the arm warmers enabled me to leave long sleeve jerseys at home.
Castelli Nano Flex warmers have been part of their inventory for seven years. They take their thermal fleecy stretch Termoflex fabric and coat it with millions of tiny nano filaments to create a water-repellent fabric finish. Drops of water stay as spherical balls on top of the fabric or bounce off the fabric.
Recently Castelli improved on their warmers by adding an insert of Nano Light fabric around the bend of the elbow (around the knees on the leg warmers). This fabric provides more flexibility and comfort, but without losing the water protection.
The arm warmer rating is at +46 degrees F, but I used them down to the 30s with great results. Below is Castelli’s rating on different aspects of the arm warmers. The water-resistant fabric works to protect you from mild showers or road spray. I disagree with the rating for windproofness, I’d personally rate it higher at a 4.

If you’ve worn arm warmers before, sometimes you get a pair that won’t stay up or are super tight on the upper arm. Castelli uses double-sided silicon grippers to keep them in place. These are unisex arm warmers and only available in black with white logo detail on the lower arm. I suggest checking the sizing chart prior to ordering as like most Castelli items, they run small. I had to size up to get the right fit.
Bottom Line
If you are in the market for a pair of arm warmers, Castelli’s Nano Flex warmers are worth a look. They are unisex, competitively priced and with features like water-resistant and breathability make them a great choice.
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