Fox Racing is one of the biggest brands in mountain bike apparel and accessories. Fox’s product range includes multiple apparel lines, shoes, helmets, gloves, jackets, and even eyewear, which is coming soon. They can literally outfit trail, enduro, and downhill riders from head to toe with everything they need to go ride.
I’ve been riding in Fox gear on and off for well over a decade. Until just recently, however, I never realized that Fox made a mountain bike bib liner. In the days before Sea Otter, Fox gathered a handful of folks from the mountain bike media to try out the latest Flexair apparel and ride around Santa Cruz, CA. In the process, I ended up with the Fox Tecbase Bib Liner, and I’ve been riding in them ever since.
I’ve been mountain biking in bib liners ever since the original Specialized SWAT Bibs came out, which was about 13 years ago. In the years since, I’ve tried just about every brand and model of liner bibs I can get my hands on, in search of the perfect pair. Now that I’ve found the Fox Tecbase, I think that search might be over.
- MSRP: $179.95
- Body material: Lightweight nylon spandex mesh
- Pad: Triple-density Italian-made chamois
- Pockets: Three rear jersey-style
- Features: Wide double-sided leg grippers, Out-stiched seams, Pee flap
- Sizes: S, M, L, XL, 2XL
Pros
- Excellent chamois comfort and support
- Super soft bib straps
- Leg grippers don't budge and also grip knee pads
- Compressive fit
- Fly/flap to facilitate nature breaks
- No useless thigh pockets
Cons
- Kinda expensive
- I never want to wear any of my other bibs
Fox Tecbase Bib Liner Details
Generally speaking, the Tebase bibs look like most of the other bib liners on the market. They’re black, they have shoulder straps, they have a chamois, and they have some pockets. But despite looking similar to the competition, it seems like Fox’s designers really did their homework to create an incredibly well-thought-out product.
The main body of the bibs is made of a blend of 80% nylon and 20% elastane. It has a slight gridded texture that gives it a somewhat mesh-like appearance, but it doesn’t have any holes in it. It’s quite thin and fairly stretchy, but the grid construction gives it support and what I’d call a moderate level of compression. All of the stitching on the seams is exposed on the outside of the shorts for comfort and to reduce the chances of chafing.

The triple-density Italian-made chamois has a mountain bike-specific shape, meaning it’s designed for more neutral and upright seated pedaling positions. It provides padding for the sit bones and perineum, but it’s a little shorter in the front, which made it easy for Fox to put a flap/fly for easier urination while wearing bibs. The pad is a medium thickness, tapering off to the edges, with higher-density padding where you need it for comfort and support.
The leg grippers are 4 inches wide with a fine silicone texture on both sides. The idea behind this is that the inside of the gripper holds onto the leg, and if you’re wearing knee pads, the sleeve overlaps, and the knee pad gripper has traction on the outside of the liner’s gripper.

Moving to the back, a denser and slightly less stretchy material connects the shorts to the shoulder straps around the mid back. This back panel is also home to three jersey-style pockets, which are common on bib liners. The pockets are baffled at the bottom to allow them to expand for gear and to overlap the waistband of shorts. There’s ample space to stash tools, tubes, plugs, snacks, and even a water bottle will fit in the middle pocket. Unlike many cargo bibs, the Fox Tecbase does not have pockets on the thighs.
The raw-edge shoulder straps are 1.75 inches wide and made from two materials. On the back and over the shoulders, the straps are slightly thicker and not quite as stretchy to provide support and stability for the seat pad. Over the chest, the straps are a softer, lighter, and stretchier material that’s very comfortable on the skin, presumably to prevent any chafing on the nipples.

Riding in the Fox Tecbase Bib Liner
When I pulled the Tecbase liner on for the first time, I thought they were perhaps a touch too small. For reference, I’m 6’0” and 170 lbs. with a 32-inch waist, and I’ve got a size medium. Every other bib liner that I currently own or have worn in the past decade has been the same size.
The difference with the Fox Tecbase is that they are more compressive than any other bib liner I’ve worn. I’d call the level of compression moderate, and similar to a higher-end endurance road/gravel bib. So, while they are a touch more effort to pull on, I’ve found they provide excellent support and a precise fit that doesn’t budge whatsoever while riding. But if you’re on the cusp of sizes, have large quads, or prefer a lighter level of compression, double-check the size chart and consider sizing up.

Along with the snug fit, the wide leg grippers provide a very effective hold on the thighs, ensuring they don’t move around at all on the trail. Fox added the fine silicone texture to both sides of the gripper, and it interfaces well with both the Leatt and Fox knee pads I’ve been wearing lately to keep the upper cuff from slipping down. Neither of these pads shifts around while riding anyway, but there’s essentially no chance of them sliding down now.
The raw-edge shoulder straps are a step up from the mesh straps with stitched trim on other bib liners I have, and more akin to what you’d find on fancier bib shorts. I’ve found them to be very comfortable against the skin, and highly effective at keeping the seat pad in place and the contents in the rear cargo pockets from sagging or bouncing around.

Speaking of the pad, I think the triple-density Italian-made chamois strikes an excellent balance of thickness and support. Its medium thickness avoids being too pillowy, while the moderately firm density is both supportive and stable under the sit bones. Time will tell how it holds up, but so far, it has been impressively comfortable.
The pad also seems to manage moisture well and hasn’t felt excessively hot or gotten soggy with sweat on rides in the low 90s F. Likewise, the body material of the Tecbase bibs breathes well and dries very quickly, especially compared to a couple of the other pairs that I have that tend to hold moisture and often feel soggy.
I also think the pocket layout on the Tecbase liners is pretty much ideal. I’ve never understood or used the thigh pockets on liner shorts that are intended to be worn underneath a baggy MTB short, so I’m glad that Fox did not include them. The three jersey-style pockets on the lower back, however, are well executed and offer ample storage for a tube, flat repair, tools, and can fit a water bottle if you choose. And if you don’t use them, which I usually don’t, they lie flat and are unobtrusive.

On top of all that, my favorite feature of the Tecbase liners is the fly/pee flap. I’ve stretched out enough other pairs of bibs and bib liners while pulling the front down to pee over the years, and I have always been perplexed why more liners don’t include a fly. It’s such a simple design choice, but one that I think makes a world of difference and generally makes my life easier on the trail.
And last but not least, the outstitched seams have proven to be very comfortable and virtually eliminate the chances of seam-induced chafing. I believe the most recent Specialized SWAT bibs are stitched similarly, and it makes a lot of sense for a garment that’s not really visible anyway.

Fox Tecbase Bib Liners: My Takeaway
If you can’t already tell, my experience and impressions of the Fox Tecbase Bib Liner have been overwhelmingly positive. These are the most thoughtfully designed liners I’ve ever used, and I actually don’t have a single complaint. I’m a fan of their more compressive fit, impressive stability, and comfortable chamois. The features are also dialed, from the outstitched seams, dual-sided leg grippers, rear cargo pockets, and, perhaps most importantly, the pee flap.
Needless to say, I’m a huge fan, and I think these are probably the best MTB bib liners on the market. At $180, they aren’t exactly cheap, but I strongly recommend checking them out if you’re looking for a new pair.
