I know people who swear by Source sandals and I bought a pair last summer, many years (~15?) since the last time I wore sandals. I remember I hated sandals as a kid, because they were uncomfortable, didn't last long (some of them lost parts during my 10 minute walk back from school) and smelled really bad, all the time. And I was forced to wear sandals: my mom says I've been stubborn since the day I was born, but I have an alternative narrative which says I've always wanted to control my destiny and make my own, informed choices. I wanted extremely comfortable and durable footwear when I decided to try sandals almost a year ago, after I damaged the Natural World snickers I bought shortly before their local distributor replaced them with cheap Chinese copies. It's hard to find durable, vegan footwear, and the love for Source sandals seems pretty universal in my circles.
Anyway, the sandals surprised me. I think they're amazing. They feel a bit too thick and too soft at first, but they become super comfortable after a week or two, when the soft middle layer of the sole loses some of its elasticity, like a new mattress. After they wear in, they're pretty much perfect: the bottom layer of the sole is grippy, and keeps you stable when you stand in a crowded bus, or walk on fine desert sand and smooth rocks. The middle layer of the sole is soft and provides great shock absorption, which is always useful. The top layer of the sole is textured and feels nice. The 3 layer sole is tall enough to keep your feet clean, most of the time, and it's wide enough to protect your pinky from table legs or stones.
If you need to wash your feet, or the sandals, these sandals are very easy to clean: the top layer of the sole doesn't get sticky (unlike that of many leather sandals) and the sandals dry quickly without cracking or falling apart, as long as you don't leave them to dry under direct sunlight. The bottom layer of the sole dries very quickly, which is great if you take them to the beach and want to continue to other adventures without having to take an extra pair of dry footwear with you. If you don't want sand in your car, these sandals come in a nice reusable bag with a zipper: I always find it useful in long trips, sometimes as temporary storage until I find a place where I can wash the sandals, sometimes as a wallet and sometimes as a bag for small items like underwear and medicine. I really like the idea of reusable and useful packaging.
Also, I really enjoy the versatility of these sandals. They're very easy to adjust using thick, long and durable velcro straps. The 3 straps give you much freedom, and I use two presets: one for day-to-day use and a tighter one for hiking. My wife has a very old, heavily abused pair of the same model. Her sandals lost their (generous) warranty years ago and they're full of cuts, but she never had to repair them, because the velcro straps work just fine even with 50 HP and most damage in the sole is in the front of the upper layer, 1-2 CM from the toes. Last Thursday, we took our sandals to a 2 days trip in Wadi Salvadora, some other Wadi and the Dead Sea (don't walk on the salt sediments barefoot, they're super sharp!) and the sandals delivered: the hiking preset almost saved my life when I walked in a narrow slope covered with sand and I have three clusters of deep cuts on my leg (thanks to a benign-looking, underwater salt crystal), but my feet are fine thanks to the sandals.
This is an amazing piece of fine engineering, with sustainability in mind. In addition, these sandals are very economical: in the long term, they're extremely long-lasting. The warranty covers the things that matter (my sandals are still covered), and I've heard of people who received a new pair from the factory, after phasing out an old pair in favor a new but defective one. In the short term, they're relatively affordable, especially if you buy them during the annual summer discounts. (However, I don't know if they're available at the same price internationally, and it's not surprising that comparable imported sandals, like Teva's, tend to cost cost much more here.)
Source came up with newer models after the huge success with the Clasic model, but they cost more, have more parts and I found them less comfortable (harder, thinner or too "ergonomic"). The Source fans I know just ignore these newer models: the Classic is the Thinkpad X220 of the sandals world, for many good reasons, and that is why I'm wearing these as I'm typing this text on my trusty old X220.
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