Free Shipping on Orders Over $99

Free Shipping Policy

Free Shipping applies to all orders placed for $99 and above
(pre-tax value). Some restrictions apply:

  • Offer valid in the Lower 48 States only
  • Excludes Travel Cases and some other oversize items (prices can be calculated in the cart before checkout)


Offer valid for 10% off qualifying items.

Some exclusions apply.

For questions, contact us by calling 1.800.627.6664

Castelli Nanoflex 2 Bib Knicker

The Nanoflex Bib Knickers are designed to be used in slightly colder temps and for inclement weather. The bib knickers start as a Thermoflex garment that is fleece lined on the inside for thermal value, then treated on the outside with Castelli's 5 layer Nanoflex treatment.

This treatment consist of a coating that is constructed from billions of microscopic filaments. The grouping of these filaments provide protection from wind and water, but are just porous enough to release moisture and perspiration from within. Nanoflex is soft and elastic which leaves the garment feeling comfortable yet supportive. Etymology of Nanoflex comes from combining the metric prefix nano with the word flex. Now combine nano with flex and you get Nanoflex, the magical material that provides millions of microfilaments that coat the thermal based fabric Thermoflex. This Nanoflex/Thermoflex combo provides ample protection from the elements in a flexible and comfortable garment.

The Nanoflex is a 3 season product that can be used in in a variety of conditions. On slightly chilly days the Nanoflex provides some added warmth on the front of your thighs and takes the edge off. If the mercury drops more you can add some knee warmers for added protection and morph the bibs into true knickers. On cold days, you can combine the Nanoflex bibs with thermal leg warmers and essentialy turn them into tights. Since they are resistant to wind and wet, you will get plenty of protection regardless of any type of inclement weather you may run into.

Castelli chose the venerable Kiss3 insert for chamois detail. It features seamless integrated technology that has soft fabric on the skin care layer is lined with 4mm of soft foam for additional comfort. The Kiss3 employs infinite shaping of the high density foam to make sure the right support is located where it is most required.


  • Weather resistant Nanoflex treatment
  • Thermoflex core material
  • Fleece lined
  • Free style uppers with mesh backing
  • Giro3 single-layer leg gripper
  • Kiss3 insert
  • Rear reflective inserts
  • 40-65° temp range
  • Perfect 3 season garment
  • Anatomic cut

Nanoflex starts out as the Castelli Thermoflex fabric. This fabric is then treated with a 5 layer microfilament coating that provides a weather barrier.
Thermoflex + Proprietary Microfilament Coating Treatment = Nanoflex.


Reg Price $119.99