Leatt GPX 5.5 FlexLock Boot Review


Words by Sourpatch

When Leatt first came to the market in 2004, they only offered one product, the Leatt Neck Brace. Sixteen years later, they now offer a wide variety of products to cover the rider from head to toe in just about every category for both the moto and mtb spaces. Leatt rounded out their moto line with the introduction of the GPX 5.5 Flexlock boot in late 2019.

For myself, I had been running the same Thor Quadrant boots that I got when I started riding moto in 2007. Those boots lasted me thirteen years, and to be honest, they could have kept going with a sole replacement. Even though I could have fixed them up, I really wanted a new pair of boots, a pair that wasn’t beat to a pulp. Drew however, has been on a boot scooting adventure recently and has tested the Alpinestars Tech 7, Gaerne SG10 and Sidi Crossfire 2 TA’s. So we’ll be putting both of our opinions regarding the Leatt GPX 5.5 boots in the review. One from a boot-slut and the other from a guy so afraid of change he resists changing his underwear.

Leatt GPX 5.5 FlexLock Boot Review

Leatt’s GPX 5.5 Flexlock boot spent a long three-years in development. The boot features adjustable boot flex, lock-out of ankle movement and force reduction technologies. The combination of these three things is what Leatt calls their FlexLock system. The LockOut of ankle movement is adjustable and capable of reducing up to 37-percent of ankle forces while also reducing up to 35-percent of forces to the knee. The idea behind this is to give the wearer a feeling of security when over-flexed.

The Cuff of the boot utilizes Leatt’s SlideLock system, the SlideLock system is essentially a one-way sliding Velcro closure that locks in place. It’s one of the coolest features features on the boots and really neat technology. Rounding out the closure system are four forged aluminum buckles with an over-locking function.

In terms of construction, the sole of the GPX 5.5 sports a reinforced steel shank that is CE certified. In addition to the steel shank, the foot peg riding zone has been extended for arch and on the ball style riding. A low-profile toe-box makes for a gear shift friendly shape. Leatt incorporated 3D-shaped impact foam over the ankle area with a unique pattern to provide heel grip. The interior of the GPX 5.5 boot uses a breathable mesh 3D inner liner with anti-slip reinforcement, meaning zero heel lift.

The GPX 5.5 FlexLock boots are available in three different colors and sizes 7-13.

Leatt GPX 5.5 FlexLock Boot Review

When it comes to footwear, fit is always a crapshoot when you get something sight unseen. Thankfully for us, Leatt’s GPX 5.5 boot offer a true-to-size fit with a fairly large toebox area suitable for most feet. I was surprised with just how soft and comfortable the interior of the boot was, something I didn’t know I was missing with decades old boots. All three of the riders who spent time in these boots were impressed with the comfort.

Snapping the buckles into place proved to be our biggest gripe with the boots. Some buckles would need an incredible amount of force one time and then close very easily another. My boots worked well about 85% of the time however Drew’s boots were problematic 50% of the time. We tried lubricating the hardware, which didn’t help but Leatt did send us new buckles. After we got some replacement buckles we felt comfortable modifying the stock buckles and think we discovered the issue. The rounded cams on the buckle hardware seem to be a bit too thick and after we filed them down Drew’s boots would close much smoother more frequently.

The one-way SlideLock Velcro is a really neat feature compared to standard Velcro. I haven’t once had any bunching with the Velcro when compared to traditional Velcro closures which would always have to be redone once the buckles were closed. It’s a small but really neat feature that gives major points to Leatt’s boots.

During the walk and jump test I found the boots to be quite stiff and as intended, the boots offered little movement at the ankle. This means protection should be great on major cases and harsh impacts, but it did have some negatives for trail riding. The sole is also quite stiff and designed for aggressive riders pushing the limits on the track.

Leatt GPX 5.5 FlexLock Boot Review

So, how do the GPX 5.5 Flexlock boots perform? We’ll be honest, they’re purpose-built boots and if you run them on the track, you’ll probably be very happy. If you’re a trail/enduro rider however, you may agree with our experiences. When it comes to fast, wide open desert riding or days at the track, the Flexlock system and the boot’s overall stiffness is a positive. Being able to squeeze the bike over whoops without having to worry about much movement brings peace of mind.

The downside comes when riding through tight, tree-lined singletrack with lots of elevation changes and shifting. Shifting requires more energy as we had to move our entire leg a bit rather than just move the toe and ankle area to get under the shifter. I also wished the boots gripped a bit better on the pegs. On stock pegs I would find my feet bouncing around the pegs on both my clapped out CRF450 and on our new KLX230 test bike, landing at weird angles and needing to be reset. Both Drew and Matt ride new Husqvarna and KTM bikes with FLO and stock pegs and did not have any major complaints regarding traction, so that could be a personal opinion or the difference between Kawasaki and Honda pegs and nicer KTM/Husky stuff.

I have probably 30+ hours on the boots so far and Drew’s boots have about 15-20 hours of use. They did not require much time to break-in, although they also didn’t loosen up much since that first ride. They are stiff boots. Sadly, in those 30 hours I’ve somehow managed to break the bracket that holds the Flexlock tab in on one of the boots even though I’ve never crashed or cased any massive jumps in them. It is an easily replaceable part, however a bit of a bummer on such new boot.

The Wolf’s Last Word

These boots are jam packed with features but many of them make the boots purpose-specific for a unique rider set. The buckles are nice and sturdy, but don’t always snap into place with ease. The FlexLock system is really neat and offers extra stiffness and protection against hyperextension, which track riders should love. The downside is it makes the boots too stiff for trails where you might be shifting a ton while standing and moving the bike around in tighter terrain. If all you ride is track and/or desert, I don’t think you’ll have many issues or qualms with these boots but we are excited to see if Leatt comes out with a more trail-oriented boot in the future, which they may or may not have eluded to having in the future.

Price: $389.99

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We Dig

Stiff (Track/Desert)
SlideLock Velcro
Decent Value
FlexLock System

We Don’t

Stiff (Trail/Enduro)
Finicky Buckles
Little Range of Motion


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