Castelli Nanoflex Bib Knickers: Good-bye Excuses

It was no surprise to me that I was impressed with the Castelli Nanoflex 2 Bib Knickers. However, even with high expectations, these knickers still managed to amaze me. I bought these knickers as a cold weather defense to be worn on days that are too cold for knee warmers but not cold enough for winter tights.

I wasn’t necessarily buying the Nanoflex knickers for their claimed water resistance, but it was a plus. That said, my first ride in these knickers was in a winter downpour. Having no desire to get on the rollers, I paired these with my go-to rain jacket and took off for a gravel ride. Granted this wasn’t the best idea with regards to my components and bottom bracket (and later resulted in me paying an “idiot tax” according to my mechanic), but staying warm and relatively dry made the ride an blast!

The Castelli Nanoflex knickers feature Castelli’s “5 layer nanotechnology” which acts to keep the soft-shell knickers warm and breathable yet highly water resistant. All of these aspects were tested on my very first ride in them.  Stinging rain beaded and rolled off the surface of the knickers. Even dirt and mud was repelled. The thermal qualities of them are also impressive.  These bibs have not been too warm for rides nearing 60 degrees, but have kept me comfortable even when the temperature has plummeted to the lower 20s (note that I do love the cold and usually dress lighter than most for the same temperature).

Castelli Nanoflex Bib Knickers

Photo Courtesy of Castelli

The Nanoflex knickers, as is common with most Castelli products, feature an aggressive-cut for the on-bike position. These knickers are tight, so be sure to size up. I am 5’ 11” and 175 pounds. I wear a large in every other brand including Assos; however, even the XL Castelli knickers still fit snugly. The pad is great and has been comfortable on 5 hour plus rides. The leg grippers are a silicon band which grips well without feeling restrictive. Again keeping in mind that Castelli cuts these for the bike position, if you walk or put a foot down a lot, you will notice that the cuff will creep up a bit.

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Overall, these Castelli Nanoflex knickers are highly impressive, and I really can’t recommend these and the entire Nanoflex collection enough. I got a good deal on these around Christmas, but even the full retail of about $140 is an amazing price for such a versatile piece of gear.

Castelli Nanoflex Knickers at a Glance

  • Warm yet breathable
  • Highly water resistant
  • Aggressive fit means comfort on the bike but size up
  • Comfortable pad for long rides
  • Reasonably priced
Castelli Nanoflex Bib Knickers

The author in his Castelli Nanoflex Bib Knickers

Disclosure: I purchased these knickers from a retailer. I was in no-way compensated for this review. My only motivation was to tell you how great they are and to take away an excuse for not riding in the cold/wet.

– Alex (Steak Sauce)