The performance the quick-drying aspect and impressive durability go some way to alleviate the painful price tag.
- Brand: Fox
- Product: Union BOA Flat shoe
- Price: £199.99
- From: Fox Racing UK
- Tested by: Ross for 8 months
Our rating
The Union BOA Flat shoes are Fox’s fully loaded, top of the range flat pedal shoe. Designed to be tough and grippy for enduro and DH use but not overly hefty for all day rides too. There’s an all new upper over previous versions of the shoe featuring a blend of welded TPU and rip stop along with a molded toe cap for added durability and protection from rock strikes.
As the name suggests, they use a dual BOA Li2 system for fastening so you can use very small rotation clicks to get the fit dialed to your feet. They also come supplied with high and low arch support options for a custom fit. I tried both and went with the high option.
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Inside there’s an EVA midsole and a molded stiffening plate to aid in power transfer and also off-bike comfort. Under the midsole there’s a D30 insert for additional cushioning. The sole itself is made from Fox’s own Ultratac rubber in a pattern designed to help grip your pedal pins.
I’m a size 45 in pretty much every riding shoe I’ve used in recent years – FiveTen, Giro, ION, Ride Concepts etc – but Fox state that the Union flat come up large and recommended trying a smaller size so I went with a 44.5. The smaller size is still pretty roomy in length and for summerweight thin socks I’d probably prefer to have a 44, but this 44.5 is fine with substantial socks.
Around the ankle area, the BOA cinches things up nice and snug and the heel area cups your foot well. You do have to be careful not to over-tighten the upper BOA though as the cuff and tongue are out-oif-the-box rather stiff and can dig into your ankle a bit and cause discomfort and pressure points. Thankfully the shoe uppers do soften after a few rides. Eventually I ran the lower BOA properly tight, and then the upper a little looser which keeps things secure and comfortable, but also let my ankle move slightly without any pressure from the cuff when pedalling or off the bike pushing.
The toe box area is quite roomy though and I found that when I did cinch things up tight with the lower BOA it caused a bit of ‘ballooning’ of the upper material. This was more prevalent in summer with thin socks on and now we’ve moved to waterproof socks season, the extra volume is much less noticeable.
Once you’ve got the BOA fitting dialled (pun intended) and you’ve done a few rides, they are a properly comfy pair of shoes. They do run warm in summer but no matter how long you’re pedaling, pushing or descending for I’ve had no foot aches, pains or hot spots. And the BOA dials allow you to make small adjustments if needed to keep comfortable.
The outer does a good job of dealing with mud and puddle splashes and while they’re not billed as winter shoes, with a pair of waterproof socks I’ve found them to be impressively weather resistant and cosy. I’m not particularly bothered about waterproof MTB shoes as mud and water just runs down your legs and fills your shoes anyway, so I’d be happy running these year round (just get the highest waterproof socks you can). And they also have the benefit of drying nice and quick which can’t necessarily be said about most MTB shoes.
I’ve used the Union BOA Flat with a range of different flat pedals (Hope, Renthal, Deity, RaceFace) and I’ve had zero grip issues. The grip is definitely up there with the best. One you get your feet set on the pedals you’re locked in and secure. I’ve not slipped a pedal no matter how rough and rowdy things have got. I’ve even added the pin spacers on RaceFace pedals (to reduce the pin height) so I can shuffle my feet a bit as and when required. The soles are also proving to be durable and so far, after a good eight months they are showing minimal signs of wear, as are the rest of the shoes.
Overall
The Fox Union BOA Flat are up there with the best. They’re comfortable, durable, work well across different seasons and if you value all out grip then they’re hard to fault. It would be well worth trying them size and fit before you buy, but if they suit your feet then they’re hard to beat. The only real downside is the cost, but I guess that’s the price for performance. Having said that, their quick-drying aspect and impressive durability go some way to alleviate the painful price tag.
I really like my Fox Union shoes. I’ve got the laced versions because I’m not into Boa.
RRP is ridiculous but they’re never full price. I bought mine heavily reduced in Go Outdoors. I might try the new waterproof ones when they’ve been out for a while.
I have a pair of the normal Union flats. But I’ve stopped wearing them since the grip is so much less than my 5:10s. I like the Fox a lot, but prefer the 5:10 grip.
year and a half in on mine – with 3 rides a week, year round.
starting to look a bit tatty but still perfectly functional.
already bought a second identical pair which got used on holiday in september and are now back in the box until spring.
Love the double boa. I love being able to adjust the fit while riding, and can quickly pull off a muddy shoe at the end of a ride rather than deal with claggy laces.
if they are less grippy than 5:10s (I was previously a 5:10 fan, had a number of their different shoes, although never the downhill impact type ones) then I can’t tell the difference and they are functionally the same. Never slipped a pedal, can lift the bike while scooping etc.