Late to this party, am into this hobby, you absolutely must heed the following:

1. learn to ride a non-powered skateboard or longboard first. I guarantee you, you do not have the balance or skills to ride a longboard at 10kph off the bat, let alone 50kph. I've snowboarded and wakeboarded for a significant chunk of my life and I'm telling you, longboarding, especially fast longboarding, is not an easy skill to master, let alone pick up as a twenty-something.

2. allsunny's comment on learning to fall is spot on. You need to know, instinctively, how to bail at different speeds. At certain speeds and obstacles you can run off, at others you have to tuck and roll, still others you will rely on your knee pads or elbow pads to protect you from impact. allsunny's comment is spot on for other reasons but for now I want to move on to...

3. protection! Always wear your protective gear! I wear wrist guards, knee guards, elbow guards, and a helmet (not full face, unfortunately), every time I ride. I don't care how good you are, if you are in your mid twenties and older, a fall on concrete is really going to mess you up. Not that it doesn't mess you up when you're a kid, just that kids have a greater potential to bounce back from these things...

OK, now on to the article itself. There's a lot left unsaid, leaving you with the false impression that you have a proper and informative guide. Unfortunately, it barely scratches the surface.

(A) Hub vs belt: hubs have more cons than just heat. Hub motors tend to get really beaten up since your motors are taking the impact of the terrain. The urethane, or "tyre" part of the hub, is also typically not easily replaceable, falls off easily, or wears badly. That's kind of changing now but for the most part if you get a cheap hub you're going to have to replace the whole thing. Furthermore, the urethane is typically very thin around hub motors and your ride quality is going to suffer as more vibrations are transmitted up.

Hubs are really quiet, though.

Belt drives have many advantages. The motors get beat up less (unless you don't have enough clearance). You can "gear up" or "gear down" a belt drive (albeit not while in motion), giving you more speed and torque options. The article makes a big deal about dust and dirt and swapping belts but most belt drives have some kind of cover and belts are cheap to replace. Most importantly, you can buy wheels from companies who actually know what they're doing in terms of urethane formulation, grip, comfort, etc. You have options with a belt drive.

They can be really noisy, though.

Remember if you get a belt drive that you need a way to maintain tension. If your kit doesn't let you do so (e.g. diyeboard kits), it's... well it's not worthless, but you'll be swapping belts out a lot.

(B) ESCs: there are ESCs, and there are ESCs. The VESC the article author mentions is indeed open source hardware and firmware, but the quality of the hardware you get is really hit and miss depending on who you buy it from - some VESC hardware cannot run in certain firmware-settable modes and will go up in flames if you try (look up FOC). Furthermore, there are so many versions of the hardware out there that it can be a nightmare to find the compatible firmware for it. And finally they're usually expensive as.

On the other hand, the cheap chineseum ESCs have their own set of problems and limitations. While cheap, they are typically not as configurable as VESCs, and sometimes lock you in component wise to the vendor's radio control system, drive and battery combo.

(C) Batteries: do not buy cheap eBay hobby batteries. I've played with these in the context of RC buggies, planes and drones, and they are really hit and miss. It is fine in the context of RC toys which you play with in a safe environment and never for more than a few minutes at a go, it's not so fine in the context of a moving EV you're standing on going at 50kph, being constantly hammered by road conditions and put out in the hot sun for half an hour to hours at a time. Unless you have taken appropriate precautions and screened the batteries and otherwise know what you're doing, I wouldn't give them a second glance.

You can look up forums for reliable battery suppliers and make your own cells or buy from those. If you want to go the DIY route, GA cells apparently do pretty well, but I wouldn't put a pack together without thinking about cell-level fusing, having either special soldering equipment or a spot welding setup, strain relief, wire gauge selection, etc. If you set it up wrong, you're going to end up with too much current running through too thin a conductor and having them glow with the heat under load. I've seen it. It's cool, but also scary... mostly scary.

(D) Oh yeah, you're gonna need a battery charger. What do you mean, you don't have an adjustable chemistry battery charger just lying around at home so you can make a choice from a variety of available battery chemistries?

Alternatively you can source a battery management system which is a circuit matched for your battery chemistry, and just plug it in to a properly set up power supply. But then you have to ensure the power draw of the drive system is set up for it.

That said, one potential advantage of having a battery management system is the ability for you to take advantage of regenerative braking capabilities of your ESC safely.

(E) Remote control. The article didn't mention this, but you're going to need one. Please don't buy a bluetooth controller, a signal hiccup at 50kph and your skin could be a smear on the floor.

Speaking of hiccups, you oughta determine, and set, the failsafe behaviour on your remote controlled EV. The typical failsafe mode is to freeroll, which means if it fails you'd better be able to ride and stop your board without having to rely on the electric crutches. Callback to allsunny's comment.

(F) Deck, wheels and trucks. So you're putting together your 50kph drive and decide to slap it on a donor deck. So easy amirite?

For heaven's sake don't do this. Longboard decks come in many shapes and sizes. Again, if you're the kind to have ridden around on non-electric skateboards or longboards, you'll have a very good idea of the available options. If not, you have to do your research. The kind of setup that is fun to ride at 10kph is decidedly deadly at 50kph (look up "speed wobble"). The wheelbase, deck shape (both lengthwise and cross-sectionally), ground clearance, softness of wheels, width of truck, stiffness of bushing, geometry of truck, etc., all make a difference. There is a fair mix of personal preference and objective necessities too.

(G) Putting it all together. It's not a PC, you can't just plug in the components and have them work. You'll want to weatherproof the components somewhat, protect them from impacts. There are also miscellaneous parts you may want or need like switches, anti-spark connectors, battery level indicators, etc.

One thing often missed in assembly, for e.g., is that people buy cool looking carbon fibre decks, crowd their receiver next to the dense batteries or high current wires, and then wonder why their low powered radio transmitter and receiver only works intermittently. Not all radios, and not all decks, but some.

In conclusion: there are a whole lot of miscellaneous matters that aren't mentioned in the post and I didn't want people reading it to think it was going to be a single-blog-post level of simplicity to jump on a 50kph electric skateboard and off you go.

Last word, I promise: 50kph is scary. All of you downhill longboarders who have earned your way through the school of hard knocks know this. For the rest of us, 20-25kph is plenty fast and hard to react on if you haven't learnt to ride on a non-powered longboard or skateboard. Have fun, and take it easy!