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Product Images

Castelli Nano Flex 3G Kneewarmer Black
Castelli Nano Flex 3G Kneewarmer Savile Blue
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Castelli Nano Flex 3G Kneewarmer 1
Castelli Nano Flex 3G Kneewarmer 2

Castelli Nano Flex 3G Kneewarmer


Pricing and Order Section

Mfg PartNum:
$69.99 pr.
MSRP: $69.99
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Nano Flex 3G KneeWarmer

For the flexibility to add and remove an extra layer on those chilly spring and fall rides, the Nano Flex 3G KneeWarmers are supremely versatile. Unlike wearing full-length tights or leg warmers, you're covered where it matters most. Your joints.

Proprietary to Castelli, the Nano Flex technology is a water-protective finish paired with their tried and true Thermoflex fabric, offering you the best coverage in all-conditions.


  • All condition kneewarmers
  • Water repellant Nano Flex technology keeps you dry and warm
  • Single, flat-lock seam ensures maximum comfort
  • Gripper is made of double-sided silicone keeping the warmers in place
  • Easy on/off and stowable in a jersey pocket
  • Castelli recommends these warmers for temperatures ranging from 54 - 68° F

B-Stock - This product has one or more B-Stock units available. These units can be purchased at a discount (see option select). B-Stock units were returned from other customers and may have missing or damaged packaging materials. These units are otherwise as new. The full manufacturer warranty applies. Click Here for more information.

Size Chart



Black - Small

Mfg PartNum: Q19578010-2 

Black - Medium

Mfg PartNum: Q19578010-3 

Black - Large

Mfg PartNum: Q19578010-4 

Black - X-Large

Mfg PartNum: Q19578010-5 

Savile Blue - Small

Mfg PartNum: Q19578414-2 

Savile Blue - Medium

Mfg PartNum: Q19578414-3 

Savile Blue - Large

Mfg PartNum: Q19578414-4 

Savile Blue - X-Large

Mfg PartNum: Q19578414-5 


Ordered by Most Relevant First
5 stars
4 stars
3 stars
2 stars
1 stars
Reviewed 1/1/2022
by pistawork
Cycling Enthusiast
Cowtown, TX
Value Rating
Overall Rating
Very Dark

When I opened the package I thought "these are not right, as in black, not blue". So much so I contacted CS and had an echat to confirm. I was ably helped and assured they are very dark but was given a RA# if I wanted to return but even better got a discount if I wanted to keep.

I find them to shift towards dark blue with my navy blue shorts and work fine with the kit. They are longer than my other Castelli Nano Flex knee warmers which is great and they fit more snugly so no creeping up and bunching behind my knees.

I am very happy with these knee warmers.

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Reviewed 2/18/2021
by Reydelvalle
Cycling Enthusiast
Los Angeles
Value Rating
Overall Rating
1 of 1 customers found this review helpful.
Knee warmers that do their job

I live in Los Angeles, so it's only been cold enough to wear these once. Tough life, I know! They generally stay up - just had to pull them up once during a 60 mile ride.

I didn't give 5 stars because as I putting them on, I could hear some seams popping, which causes some concern as to their longevity. Will certainly provide updates as I get a few more uses out of them

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Reviewed 1/11/2021
by Anonymous
Cycling Enthusiast
San Luis Obispo CA
Value Rating
Overall Rating
1 of 1 customers found this review helpful.
Extended length and silicone grippers on both sides to ensure they stay put.

I wear these with standard bib shorts and the extra coverage on colder days is great for staying warm. The tops have grippers on the inside next to your skin and outside next to the shorts so they stay put.

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Reviewed 4/25/2020
by Anonymous
Daily Commuter
washington state
Value Rating
Overall Rating
2 of 3 customers found this review helpful.
good fit and finish

replaced my pearl Izumi knee warmers with these and have been very pleased with how well they perform

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Mechanic's Corner

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All about leg and arm coverings to keep you protected in inclement weather.
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