Fox’s Union Clipless is a technical shoe with an easy-clean build that's great for gravity applications.

Product Overview

Overall rating:

Score 8

Fox Union Clipless shoe


  • • Easy to clean
  • • Customisable insole
  • • Large cleat pocket, with lots of adjustment
  • • Modern styling and construction
  • • Stable under power


  • • Heel pocket can rub
  • • Price is relatively high


I love the Fox Union Clipless shoes’ wipe-clean upper, but they aren’t as comfortable as Crankbrothers


Price as reviewed:


Fox hit a home run with its latest Union flat pedal shoes, going straight into the shortlist of best mountain bike shoes. Can it do the same with the clip-in versions? I’ve been testing the cheaper Union, and high-end Union Boa (as used by the Santa Cruz Syndicate DH team), to find out.

Design and specifications

Like the brand’s excellent Union Flat shoe, the clip-in model gets a striking one-piece moulded upper that gives an exceptionally clean, modern look. The co-moulded rubber reinforcements stretch around the toe and heel, with perforated pockets to allow ventilation and airflow. And the overall result is an impressively seamless upper that is extremely easy to wipe clean, as there are very few crevices for mud to hide, and the rubber dries quickly.

Securing the shoe, to ensure stability when cranking on the pedals, are traditional laces and a broad velcro strap. Fox has kept the laces short, so they don’t require extra tidying, and the strap could be cinched up pretty tight without creating a hotspot across the top of my foot. It’s doesn’t even out the pressure as well as the dual Boa version, and the lace/Velcro opening was more difficult to get my foot into, but this shoe is significantly cheaper than the Boa option. £60 cheaper to be precise. With that in mind, I believe most riders will be happy to trade a little convenience for a reduced outlay.

Fox Union Clipless shoes

The long cleat pockets allows you to run a rearward pedal stance to put more pressure through the pedals and improve DH stability.

Twin elastic gussets keep the tongue in position and Fox has also given the Union Clipless a deep heel pocket, both of which improve foot stability. The heel pocket does have a fairly pronounced, square-edge that I could feel through my sock, and that rubbed slightly when walking and pedalling. In that respect it’s not as cosy as my favourite Crankbrothers Mallet Boa shoe.

One aspect where Fox does have an edge is with its exchangeable arch support. Included with the shoe are two different supports – for high and low – and these can easily be swapped out by removing the insole and using the velcro attachment. It’s a simple but useful way of customising the shoe to suit your foot.

Flip the Union over and there’s an Ultratac rubber outsole and massive moulded cleat pocket with long slots that give an ample range of adjustment (36mm). A thick rubber perimeter moulding and ramps at either end help guide the cleat into the pedal.

Fox offers seven different colours and a size range from 37 to 47 EU.

Fox Union Clipless shoes

The wide strap makes tying laces and getting your foot in and out tricky, but keeps the shoe locked down under hard pedal efforts and big pulls.


Compared to my favourite Crankbrothers Mallet shoes, the Fox Union Clipless has a less bulky upper, with more stability and a slightly stiffer sole. It’s not as cushy and comfortable as the Crankbrothers, which I found most noticeable on long rides and when walking around.

I had no issues getting a good cleat placement, and the sole markings made it easy to replicate left to right. Fox even describes the cleat zones as ‘power’ and ‘control’ to take out the guesswork.

Weight is on par with the Crankbrothers, as is the price considering the Fox doesn’t come with any cleats, and the Crankbrothers does.

Fox Union Clipless shoes

The one-piece, rubberised upper it super-easy to wipe clean and dries quickly.

I’ve worn these shoes a lot, and so far they’re holding up reasonably well. There is some minor degradation of the rubber around the lace eyelets and a shallow crease forming on the side of the shoe formed as the sole bends. However, I did managed to rip the laces out of the eyelets, and rip the upper, when I hit a stump with my foot. It was a big impact, but I wonder whether a similar impact on a shoe with more traditional construction would have done as much damage, as there would have been reinforced eyelets and stitching to stop the tear.

Fox Union Clipless shoe

A big impact against a stump ripped the laces out of the eyelet. But my foot emerged unscathed. 

I found weather-proofing to be very good considering this is not a specific winter shoe. It stays relatively dry for longer than most shoes, and dries quickly too. Yet I didn’t overheat wearing it in the summer months.


The Fox Union Clipless is not a winter-specific shoe, but it works really well in wet and sloppy conditions because it’s so easy to clean. There’s a good deal of stability through the entire shoe, both upper and sole, and it’s easy to clip-in and out of platform trail pedals, such as Crankbrothers Mallet DH and Mallet E. I found comfort was reasonable, but not outstanding, while the tunable arch support is a genuinely useful feature.  In terms of value, the Crankbrothers Mallet Boas are £20 more expensive, but you get a Boa closure and free cleats, which more than makes up for the difference.  While the Fox Union Clipless won’t be usurping Crankbrothers as my go-to summer shoe, the easy-clean construction makes them my first choice for muddy rides.


Weight:943g pair
Sizes:37-47 EU