Leatt 5.5 FlexLock Boots Review

The Leatt FlexLock 5.5 boot has been out for a few years now, but having just bought a new pair, my first impressions were so positive that I decided to write my own Leatt 5.5 FlexLock boots review.

I bought the Cactus Enduro boot. The Enduro boot has a chunkier tread pattern, important for enduro and trail riders for those times when pushing the bike on slippery trails is necessary. It is also available with a smoother sole which is what motocross riders are looking for.

I was unsure whether I liked the color combination of cactus green and orange at first, but having them around for a few days now, the color is growing on me. I ride a KTM so of course the orange is a perfect fit.

The Leatt Flexlock enters the market as direct competition to the Alpinestars Tech 7 and Tech 10 and now gives riders another option in the top-of-the-line boot market.

First Impressions

As you slide your foot inside them for the first time, you instantly feel the quality of the plush interior. The 3D foam around the ankles is immediately evident, and there is no feeling of heel lifting when taking your first walk around in them.

My last pair of boots, The O’Neal Rider were a bit tight at size 10, so I went for a size 11 with the Leatt. I have wide feet, and these feel very comfortable, so they are suitable for riders with wide feet. By all reports I’ve read they are true to size.

Leatt is a well-known quality brand, first coming to the market with the Leatt neck brace. They now offer a wide range of riding gear to cover the rider from head to toe.

The CPX 5.5 boot has been 3 years in development and testing by pro riders from all over the world like Jonny Walker and Ryan Sipes.

In terms of aesthetics, the Leatt 5.5 boots have a modern and aggressive design that’s sure to catch attention. The sleek lines and carefully chosen color combinations certainly add to their overall appeal.

The Leat 4.5 and 5.5 Boot. What are the differences?

The 5.5 is the bigger brother to the 4.5. They look very similar, but there are a few differences:

  • The buckles are forged aluminum on the 5.5 and a polymer composite and the 4.5. They are replaceable on both boots
  • The 4.5 does include the Flexlock system and the hyperextension protection of the 5.5
  • The inner heat shield face of the boot is replaceable on the 5.5 but not on the 4.5
  • The sole is replaceable on both boots

If you’re a really aggressive trail rider, a racer, or are looking to protect an old ankle injury, the 5.5 is the more likely choice for you.

The Protection System

One of the standout features of these boots is the FlexLock system. So what is this FlexLock system that gives the boot its name?

Leat claims it reduces the forces absorbed by the ankle by up to 37% and the knee by up to 35%. I’m not sure how this is measured, but looking at the shank at the archiles tendon area and the Flexlock plate on the outer ankle (below image) I can believe it.

The boots come with another interchangeable insert to allow you to adjust the sideways flex.

Leatt FlexLock

The LockOut system allows ankle movement when riding, but limits hyperextension of the ankle by locking out in both downward and upward directions. Too much movement at the ankle is a bad thing and can lead to ankle injuries.

Leatt 5.5 FlexLock

This was a big selling point for me having lost about half of the movement in my right ankle due to a nasty injury requiring pinning, so preventing hyperextension in both directions is important for me to protect the old injury.

Slide Lock Closure At Cuff

Leatt has developed an auto-locking, one-way sliding velcro that ends the problem of bunching up the velcro as you are closing the top buckle. It was always one of those annoying little things that you had to readjust the velcro as you closed the top buckle.

Leatt slide lock closure

The one-way velcro simply slides tighter as you close the top buckle and doesn’t come off until you lift it off. A small thing but a nice feature.

In my opinion, it is only a matter of time before we see this feature on other brands of boots.

There is plenty of adjustment to allow for knee protectors or knee braces inside the boot if you use them.

Leatt 5.5 FlexLock heat shield

The inner face of the boot that grips the bike and also acts as a heat shield against the engine is flat, textured, and grippy to give you a firm feel of the bike. The construction looks tough yet flexible.

Past boots I’ve owned have had rigid TPU plastic protection to the inner ankle area, but when impacted against footpegs, engine, and rocks, they have cracked and subsequently ended the life of the boot. This was an area I paid extra attention to with these boots. I found no reports of this area cracking. The upper section is replaceable.

The buckles are forged aluminum and stainless steel base. The lower buckle has a plastic protection ‘ramp’ type edge to deflect impacts away from the buckle. The buckles are replaceable in the unlikely event you break them.

The Sole

The 5.5 FlexLock Enduro boot comes with a chunky treaded sole which is important for enduro and trail riders for those times when you have to manhandle the bike on slippery rock or muddy terrain.

Motocross riders will be looking for the smoother sole option which is also available, which allows easier skimming of the boot through berms and ruts.

There is an extended area of the harder sole which allows the rider to ride with the pegs either on the instep or the balls of the feet, and is steel shank reinforced. This section is replaceable, so allows for an extended boot life.

Leatt 5.5 FlexLock sole



  • Forged aluminum buckles with an Over-lock system and stainless steel base
  • 3D-shaped impact foam at ankles for added protection to prevent the heel lifting
  • The inner (medial) face of the boot is flat and grippy for a great feel of the bike
  • Steel shank reinforced and CE certified sole with DualZone hard construction to extended footpeg area for arch and on-the-toes riding style


  • FlexLock System allows adjustable lower boot flex in the sideways movement with interchangeable inserts
  • LockOut ankle movement: up to 37% reduction of ankle forces and up to 35% reduction of forces to the knee
  • CE tested and certified as: prEN 13634:2017


  • Breathable mesh liner with anti-slip reinforcement and is moisture-wicking
  • Fit: Comfortable even for wide-foot riders
  • Closure: SlideLock velcro cuff system for a one-way sliding closure
  • Toe-Box: Low-profile for easy gear shifting
  • Sole: Enduro pattern for grip when pushing the bike


  • Many replaceable parts
  • Unique Slidelock velcro not found in any other boot
  • Excellent value for money compared to other top-flight boots


  • May feel too stiff for some trail riders, but track riders will like

Update: First ride.

Leatt 5.5 FlexLock ride review

After my first ride with these boots, I must say I had high expectations after reading all the reviews. They didn’t disappoint.

The ride took in some pretty rough terrain – loose rocks, log crossings, deep sandy creek beds, deep clay ruts, and the boots handled it all with ease.

I was expecting a bit of stiffness out of the box after reading some reviews, but these boots felt comfortable and flexible right away.

My previous boots were the O’Neil Rider boots, which I reviewed back in 2019, and they have served me well, but they are an entry-level boot, and good value for the money, but more suited for easier trail riding, than hard enduro-type terrain.

The inner face of the Leatt 5.5 has a flexible and grippy surface that gave me a good feel of the bike, something I was particularly conscious of.

The buckles were easy to operate and locked firmly in position and stayed there.

The only nit-picky thing I can criticize is that they squeak a bit when walking. This may be because they are still new, but I’m sure a bit of silicone spray would fix that.

I can see getting many years of use out of these, and with most of the parts replaceable, it’s easy to prolong their life even more.

So all in all, very happy with my new boots.

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Is there a boot that you can highly recommend and has served you well? Please feel free to leave your thoughts below.

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