SQUIRREL_13089869
Fox Union BOA Flat’s Ultratac outsole rubber is impressively grippy on all but the roughest terrain, making them a legitimate competitor for your cash.
Sporting two Boa Li2 dials per shoe, the Union’s fit is ultra-adjustable.
A moulded toe cap is joined by reinforcement to help protect against rock and ground strikes.
Externally, the upper parts are bonded together – rather than stitched – to help boost protection from water and mud ingress. A textured, high-density print is found in high-wear areas to improve its lifespan.
An ethylene-vinyl acetate (EVA) midsole is claimed to provide cushioning and comfort, while a nylon shank should tune stiffness without sacrificing comfort, according to Fox.
Thanks to a replaceable section on the underside of the insole, the amount of arch support can be adjusted.
The Ultratac outsole uses a hex-lug design, popular with many flat pedal shoe manufacturers. These lugs increase in width towards the heel and toe to help provide off-the-bike grip.
They’re available in sizes EU37 to EU47, and my pair of EU42.5 weighed 806g.
Fox Union BOA Flat performance
Size and fit
The toe box is generous, which means your toes don’t feel cramped with plenty of space to move around.
However, the rest of the shoe tightens and narrows around the middle of your foot and the heel, feeling narrower than the Shimano GF800 and Ride Concepts Tallac BOA.
There’s plenty of stability-inducing control and support for your feet, but you aren’t cramped or restricted. They balance lightly compressing your foot with comfort well.
The shoes come fitted with lower of two arch support options installed. I didn’t feel like arch support was lacking so left the lower version installed, but your needs may differ.
Tightness and fit can be adjusted very accurately and in two zones thanks to the dual-Boa design. This is great for balancing comfort and control.
Pressure is created evenly across the tongue, too.
Feel and grip
Feeling quite stiff, the shoe does a good job of helping your feet maintain their shape on the pedals without overly insulating inputs and feel.
There’s not a lack of feedback or excessive numbness, just a reassuring solidity that makes the shoes feel more robust than their weight suggests they should.
Although the ankle cuff design is slightly asymmetrical (the inner is higher than the outer portion) I still bashed my lateral malleolus on my cranks more than other shoes I’ve tested.
While not terrible, increasing the height of the internal cuff would vastly improve comfort.
Grip is good overall, rivalling the slightly harder compound of Five Ten’s Trailcross shoes. Once placed, it’s not possible to move your foot on the pedals without lifting it clean off.
The same is true for most bumps, your feet remain secure on the pedal’s platform. But up the ferocity and they can slide and drag over the pins until your foot butts up against the cranks or the bike’s chainstays.
Positively, that means you can twist your feet on the pedals to help control the bike, unlike others that prohibit all movement.
How we tested
Alex tested these three pairs of shoes back-to-back on the same trails in the same conditions, using the same pedals; Deity’s T-Mac, Crankbrothers’ Stamp 7, and Renthal’s Revo-F. Alex was looking for durability, comfort and most importantly, grip.
Also included in this test:
- Fox Union BOA Flat
- Ride Concepts Tallac BOA
- Shimano GF8 Gore-Tex
Fox Union BOA Flat bottom line
A surprise performer, the Fox Union BOA Flat shoes shouldn’t be discounted as a legitimate alternative to the most established brands.
While they’re not the grippiest, they’re still very good.
The amount of fit adjustability via the dual-Boa dials and arch support is commendable but they’re costly.
SQUIRREL_13089869
Product
| Brand | Fox_racing |
| Price | A$350.00, €230.00, £210.00, $225.00 |
| Weight | 806g |
Features
| Shoe closure | dial |
| Features | Size: 38-47 Colours: Black; Vintage White; Cocoa Brown; Dark Shadow Grey; Military Green (colours vary by country) Materials: TPU, Eva, rubber Outsole: Ultratac™ |
