LAKE MZX304 Winter Boots: Long-term Review
Hot on the heels of their release onto the market, I began riding in Lake’s MZX304 winter boots in December, 2019. A lot has changed in the world since then, yet a lot remains the same. Keeping feet warm over hours of riding outside in real winter remains a challenge. I wrote a detailed ‘first impressions’ piece about the boots in 2019, which you might wish to refer to, especially on the topic of fit. Here, I’ll cover me experience riding in the boots over two winters, and contrast them against Lake’s MX145 and new MX146 models.
Break-in
It’s always important to factor how our footwear will break-in when comparing ol’ faithful pairs with brand new ones. Insulated boots are generally going to see compression of their insulation occur through a break-in period; loft will be reduced. A well-worn pair of boots will tend to feel more spacious than a brand new pair in the identical size. At the same time, the more roomy a given boot is, the less pressure the uppers will receive from being secured around the foot, and the more loft will be preserved within the boot’s structure.
The MZX304s are designed specifically to limit the possibility of overtightening the boots and restricting blood-flow. Their structural design also limits compression of insulating material within the boots, which leads to a more consistent fit and warmth function over their life. My pair has not changed in either respect since I began wearing them in 2019 (about 100 hours).
Fit and Function
Fit and function are closely bound when we talk about the primary task of winter-specific cycling footwear: keep feet warm. The way we fit winter shoes/boots ought to always be for ensuring warmth over the longest duration we are interested in riding. This priority sits above ‘performance.,’ because warmth is what makes winter riding tolerable and sustainable, while performance falls across a spectrum, and is not a matter of ‘go versus no-go.’
ALL cycling footwear is the product of a process of priority definition and compromise. With every decision designers and manufacturers make there are pros and cons. The way each brand weighs priorities against each other is determined by their ethos, the way they perceive their place and identity within the industry and market, and the sort of cycling experiences that inform their understanding of rider requirements and values.
Lake, the first company to build winter cycling boots, remains dedicated to building options that prioritize function, which drives their approach to fit. The idea here isn’t to continuously pump out 'the next hot-looking’ style or colourway to get riders amped and spending money. The idea is to deliver solutions that enable riders to enjoy their time riding bikes outside, even when they don’t have years of experience riding in the winter.
Weird is good
The MZX304’s fit feels weird at first because it’s not trying to feel like a summer shoe. For summer riding, our priorities for riding with clipless pedals vary. For example, if I’m going to take on a 300km ride on pavement, and want to do so on well-paved roads at the highest speed possible, I will prioritize aerodynamic drag reduction and low weight over comfort. I will anticipate my feet will likely swell over the day, and they might hurt a bit for the last hour or two if my shoe can’t accommodate that. In contrast, if I’m planning a 300km day over mixed terrain, which will involve rough surfaces, I’ll prioritize comfort over aerodynamics. This means I’ll wear a heavier and more compliant shoe, which won’t feel as ‘direct’ and efficient as my ‘fast’ option.
The 304s benefit from not trying to be one piece of footwear to cover a huge swath of riding. It’s a legitimately cold weather boot that doesn’t claim to be anything else, which means it has a fairly constrained use-case that can be optimized for. The degree to which the rider winds up with an optimal set-up, however, depends on how the boots are fit. Hence, Lake has taken measures to eliminate the possibility of making an already challenging task worse: overtightening. This is accomplished through the use of a VERY rigid tongue, in combination with BOA’s cable closure system.
The stiff tongue Lake deploys plays a dual role. First, it resists compression from the wire ‘laces’, in tandem with the stiffly structured uppers of the boot. Second, the height of the tongue enables the rider to apply pedaling pressure with the front of the shin, which drives the whole of the boot’s upper structure. This is a benefit to the rider because it affords an alternative to pressing down on the pedals with the sole of the foot exclusively. As we do that, we restrict blood flow to the bottom of the foot AND compress the structure of our socks (assuming we have loopy insulation), AND eliminate air between soles and footbeds. Firmly planting the sole of the foot onto the footbeds for hours at a time drastically reduces the body’s ability to keep feet warm. By literally leveraging the 304’s tongue, we can drive the pedals down while raising the ball of the foot off its footbed. Again, this is enabled by the holistic design at play. The stiff tongue and upper ensures the foot has room above to lift off the footbed. Would we want to do this in a summer shoe for road racing? No. But for winter riding, yes, we want this.
The challenging dynamic at play with the 304 in a world of internet ‘intel’ is that Lake’s approach is novel and often misunderstood. The boot feels nothing like anything else, and it is not necessarily intuitive for riders to understand why it is as it is. It might be tempting for riders to combat the perceived ‘excessive’ roominess of a 304 when fitting in a store, based on prior experience with cycling footwear. This is where I see an advantage to following Lake’s sizing process and taking their advice on sizing. This will almost invariably lead to a fit that is larger than folks expect. And it will surprise many to know that you can actually order two different sizes within a pair, to accommodate asymmetry.
Living with MZX304s
After about 100 hours of riding in conditions between -5C and -25C, my 304s still feel unique every time I put them on. I wear one size up from my summer shoes (details here). A couple compromises inform my decision to wear the 304s instead of my MX145s for certain rides. For road and snirt riding, I tend not to venture out if it’s colder than -15C; I prefer warmer than -10C. Between 0C and -5C, I’ll consistently be warm enough in my MX145s, especially if I use shoecovers (these ones fit well).
Below -5C, I consider how long I’ll be out for, wind exposure, and whether it’s dry or wet. The 304s don’t clear my road crank-arms nearly as well as my MX145s, and don’t really jive with tights. They are lighter than they look, however, so that doesn’t factor much. Mainly, they don’t feel quite ‘right’ for my road riding, so I almost always choose my MX145s. In contrast, winter rides off-road around the same temp make for a more tricky decision. My MX145s are much more snug-fitting, which increases my feeling of control over my bike on singletrack. They will never be as warm, but if the riding is intense, I can remain comfortable in them in colder temperatures than on the road. When its around or colder than -10C its easy to choose the MZX304s and accept that I’ll have more of a vague feeling of connection with the bike. This comes with the ability to move the foot around inside the boots.
I’m still learning how to get the most out of the 304s when it’s really cold out. Since I tend to avoid riding outside when it’s colder than -15C, I have sporadic opportunity to experiment with different sock combinations to deal with really cold days. As our feet breath, the moisture that builds up in our footwear increases the rate of heat transfer (electron flow) to the metal baseplates of our clipless pedal cleats. This sizeable chunk of steel functions like heat-sink, and ‘wants’ to reach homeostasis with our foot. The colder the plate is, the more heat it draws from us. Moisture management remains a primary design requirement for Lake, but there’s only so much you can do while also protecting the foot from wind and heat loss around the foot. Thanks to the combination of roomy internal volume and stiff tongue, chemical warmers can be used under the foot without cramping it. Since the foot can actually lift off the footbed while riding, chemical warmers can receive air, which is required to keep them ‘burning.’ If they are crushed they don’t work well.
During a cold snap in January 2022, I rode four hours of singletrack on my fat bike between -17C and -20C. With chemical warmers under the balls of my feet I was warm and comfortable for the entire time. This was a fantastic experience, since it had been years since I’d used chemical warmers, and had almost forgotten about them. My MX145s also fit them, but after I ran out of a supply a few winters ago, they fell out of my usual set-up for really cold days. I don’t love relying on single-use items for anything, so I wouldn’t want boots that always required chemical warmers. For me, the 304s probably only need them below -15C, unless I’m only riding for an hour or two.
Concluding Thoughts
There’s nothing magical about these boots, and I’m not going to pretend my feet have never been cold in them. I’ve fallen through ice and not had water get into the boots. I’ve ridden long, flat rail trail and paths and had cold feet. I’ve ridden 100km on my fat bike and been comfortable.
The truth is it’s probably always going to be challenging to keep our feet warm while using clipless pedals. Sure, Lake and other brand could build MEGA boots with 1” thick outsoles that would probably keep our feet warm at ludicrously low temperatures. They could also build in electric heaters. The more nuclear they go, however, the narrower the use-case becomes for whatever they build. And going MEGA introduces new potential problems. For example, a 1” thick outsole would require saddle adjustment for each time MEGA boots would be used, versus any other pair of riding footwear. Electric heating would introduce a complicated failure point, and add yet another thing that we can forget to charge, lose batteries for, and wind up with a gong-show of a life-cycle management scenario.
Lake actually do build a pretty MEGA boot already, which I personally don’t have interest in for myself, since I really just don’t want to ride when it’s colder than -20C. If your winter riding is all about colder than -15C, the MZX400 Extreme is probably the model for you. The MZX200 falls between the 304 and new MX146, with the versatility of being rideable with clipless or platform pedals. The new MX146 incorporates improvements to the fantastic MX145 that increase protection from external wet, while also helping vent internal moisture. The 146 is slim enough to allow riders to add shoe-covers when riding outside its intended temperature range, which isn’t the case for the other three models.
Whatever model you might already have, or choose to invest in, maintenance is actually a thing, just like with your bike. Dirt, and salt, especially, dry out the materials that comprise each model, and can break down the adhesives that hold them together. Each of them also use a DWR coating to shed water, which needs to be renewed regularly. Lake makes it easy for us with their leather care kit, which can be used for any and all leather shoes/boots we have.
If there’s a parting thought I’d like to leave you with, it’s that winter footwear is probably never going to be a one-and-done thing. As boots continue to improve and expand our riding opportunities in cold weather, we’ll continue to ask more from what we have. The goal-posts keep moving, and Lake is doing their best to be stay on, if not a little ahead of the ball. If the MZX304s seem weird to you today, that’s probably because Lake is playing an active role in delivering novel solutions for use-cases most of us don’t yet fully understand. Innovation is complicated; I hope this piece has helped you understand what Lake is trying to accomplish with the 304, and how it might fit into your cycling life.
I welcome any and all feedback and questions, thanks for reading!
