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CastelliNano Flex 3G Knee Warmer


Item # CST00UM

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Item # CST00UM

Nano Flex 3G Knee Warmer

Castelli was an early pioneer of water-protective thermal fabrics, having recognized just how beneficial they are for cycling applications. Don't assume these knee warmers are exclusively for rainy rides on wet roads, however, as the water-repellent fabric is also highly breathable, making them a great option for cooler dry days, too. The best part is if the sun comes out, you can easily slip them off and stow them in a jersey pocket, unlike knickers and full-length tights.

  • Knee warmers that work well for both wet and dry conditions
  • Nano Flex fabric keeps you warm and dry throughout the ride
  • Breathable construction prevents clamminess and overheating
  • Single, flat-lock seam ensures maximum comfort
  • Double-sided silicone gripper keeps the warmers in place
  • Easy to take off and stow in a jersey pocket if things warm up
  • Recommended for temperatures ranging from 54 - 68-degrees Fahrenheit

Tech Specs
MaterialNano Flex 3G
Recommended Useroad cycling
Manufacturer Warranty1 year


Arm & Knee Warmers





Rider Weight

99.2 - 132.3lb

(45 - 60kg)

99.2 - 132.3lb

(45 - 60kg)

132.3 - 154.3lb

(60 - 70kg)

154.3 - 176.4lb

(70 - 80kg)



Short/Jersey Size XS - S S - M S - M L - XL 2XL - 3XL
Short/Jersey Size:
Take your typical cycling short or bib sizing for comparison.

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    What do you think about this product?


    >Rating: 4


    I've used it several times
    True to size
    Size Bought
    6` 1"
    152 lbs

    Nothing bad to say about these - fit is spot on, warmer than my Pearl knee warmers, snug, stay in place. I'd buy another set in a heartbeat.

    >Rating: 1

    Ripped Putting Them On....The First Time

    I've used it once or twice and have initial impressions
    True to size
    Size Bought
    5` 11"
    190 lbs

    What a garbage product. Pulled them out of the wrapping & put them on to ride & the fabric came unattached from the gripper. This is my last go around w Castelli, the quality is non-existant with their products now.