Two and a half years ago when I received my first pair of bib short liners from Louis Garneau at Sea Otter, I was struck by the genius of creating a pair of bibs specifically to be used under a pair of baggies. Fast forward to today and almost every single brand is making a pair of lightweight, breathable bib liners for use with baggie shorts. Mavic’s XA Pro Under Bib Short is their entry into that space.
The majority of the shorts’ surface area, from the side panels to the straps to the back, consists of a durable mesh to offer maximum ventilation and minimal weight. The waist of the bibs provides plenty of give to eliminate bunching, and the front is low enough to answer the call of nature without having to strip down completely.
Mavic refers to their chamois pad as the “Ergo Insert,” claiming it offers “comfort, support and moisture management.” The main pad is thick and cushy, with a minimal secondary layer positioned around the main pad.
Finally, the leg openings include silicone grippers to help keep the bibs in place. I found this to be a nice touch for a pair of bib liners. While many standalone bibs offer grippers on the leg openings, most bib liners, in my experience, don’t.
Out on the Trail
I used the XA Pro Under Bib paired with Mavic’s XA Pro Short as well as other outer shorts from different brands, and I found it to integrate well with every short I paired it with.
Incorporating mesh up and down the sides of the short, on the back, and on the straps is, in my opinion, the standout feature. Surprisingly, when I recently looked at a few bib short liners at my local bike shop, the amount of mesh included in the construction was minimal. If the liner bib is truly designed as a liner, it makes sense to remove as much fabric as possible for ventilation, and Mavic truly took this philosophy to heart.
As I mentioned above, I found the inclusion of silicone leg grippers to be a great feature.
The silicone strips helped keep the bib firmly and evenly in place. While it’s not time for knee warmers just yet, once fall arrives in full force, the silicone gripper will prove to be a massive boon when striving to keep warmers in place.
The Ergo Insert chamois provided beefy padding, which is a nice departure from many chamoises that only offer a very low profile, minimal pad. If you want maximal padding, this chamois could be for you! While the thick pad doesn’t extend very far throughout the chamois, the lower profile layer that it’s connected to provides protection to eliminate the possibility of chafing from seams that come too close to the saddle. I’ve experienced chafing and saddle sores from seams that ended up riding between the saddle and my body, so I find this design to be very thoughtful.
I only have one complaint with these shorts, and unfortunately it is a big one: on every single ride that I’ve used the XA Pro Under Bib, it has left me feeling “dry” shortly into my ride. Now I know that some riders prefer to not use Chamois Butt’r or any lubrication–I am not one of those people. No Chamois Butt’r? No ride. (At least, nothing longer than a commute.)
I have tried all types of Butt’r applications with these bibs–directly to skin, directly to chamois, both skin and chamois, increasing the amount of Butt’r that I use… without fail, the “moisture management system” succeeded in absorbing all of my Butt’r into the thick pad, leaving my hind parts dry and chafing as all-day rides wore on.
Again this could be personal preference, so if you prefer a very dry rear end, by all means, go purchase this bib short. But for me personally, the dryness was so bad in the Mavic bibs, and all of the other bibs in my collection have either worn out or have some other type of fit issue, that I couldn’t envision myself using any of the bib shorts in my drawer for a three-day bikepacking trip on the Colorado Trail. I was so desperate that I had to go down to my LBS, try on a variety of bibs, and purchase a brand-new set before my trip. Some things you just can’t compromise on.
Thanks to Mavic for providing the XA Pro Under Bib Short for review.