from Hacker News

The Curious Design of Skateboard Trucks

by bze12 on 9/25/22, 7:50 PM with 64 comments

  • by bmalicoat on 9/25/22, 10:45 PM

    I really appreciate the technical write up of how trucks work. As others have pointed out, skateboarding is all about feel, and not efficiency. My favorite example of this is Daewon Song, one of the most skilled and creative skaters of all time. Somehow he rides a board with no top bushing on his front truck! [1] Even most skilled skaters would have a hard time rolling down the sidewalk on this, let alone tricking it in any way.

    [1] https://www.youtube.com/watch?v=pt--3DX-md0

  • by robert-brown on 9/25/22, 8:51 PM

    Roller skating plate trucks are similar to skateboard trucks.

    Kingpin angle affects cornering ability. Kingpins at higher angle from vertical corner more sharply, so skaters doing figures tend to prefer more vertical kingpins than dance skaters, who want to be able to do deep curves. For instance, kingpin angle is the major difference between Snyder Super Deluxe and Imperial plates.

    Durability is a serious consideration for roller skating kingpin angles. It's painful when a kingpin breaks and more common with less vertical kingpins, so most skaters doing freestyle will choose a plate with kingpins closer to vertical. Roller skate plates also often have a "jump bar" connecting the two trucks to decrease the chance that a kingpin will break when a jump is landed. Sometimes even a jump bar breaks.

  • by captaincaveman on 9/25/22, 10:18 PM

    Yeah, this guy doesn't (as he admits) understand a skaters mindset or culture. If you ride Indy's you're buying into classic solid trucks, and if you been skating a long time you are likely to be nostalgic.

    On a more practical aspect, you don't want to relearn the feel of your trucks, and for what benefit, if the word was they grind better, or are lighter without a reduction in strength, maybe, but neither are likely to be more than marginal. Also skaters can be a bit superstitious, have a crap session, blame the stoopid new fangled trucks.

    Anyway may take on it, but not skated for years.

  • by jmkd on 9/26/22, 10:33 AM

    You can replace the wheels, bearings and even deck on a skateboard with fairly manageable consequences.

    But new trucks are a disaster you wouldn't wish on anyone.

    No one wants traditional truck designs to change because that would be like new trucks x100.

    This all relates to how difficult skateboarding is, and how your entire body's muscle memory is utterly reliant on a very specific set of reliable behaviours from your trucks.

    'Improve' the trucks and the skater will get worse. So we're just not interested.

  • by nopenopenopeno on 9/25/22, 9:15 PM

    This article doesn’t even discuss the eternal problem of broken kingpins. Skateboarders don’t care about “turning efficiency”. I don’t even understand what that is.

    If you want to make better trucks, make some where the kingpins don’t break all the time. Every skateboarder will be buying your trucks within a year or two. You’ll be an overnight success guaranteed.

  • by bdowling on 9/26/22, 5:06 AM

    > Your Browser Is No Longer Supported

    > To view this website and enjoy a better online experience, update your browser for free.

    Yes, I'm on an old laptop, but it works with most sites. No way to even let the current browser try. It's just a blog post. Kind of a fail, if you ask me.

  • by stevage on 9/25/22, 9:50 PM

    I met a guy in a pub once who had invented a new type of truck. I'm not a skater so I didn't totally understand the significance, but somehow it could flip 180 degrees while being ridden. Apparently this opened up new kinds of tricks.

    He had patented it at vast expense and was in discussions with a couple of big retailers, and manufacturers.

    This was late 2000s. I wonder sometimes if anything came of it.

  • by fatneckbeardz on 9/25/22, 10:36 PM

    the cat food can thing is perfect here.

    there are, in fact, TKP trucks on longboards, there are extensive discussions on r/longboarding about the differences, and what it boils down to is that a skateboard is an individualized piece of equipment, and it will work differently with every human being because of the geometry of their legs, feet, ankles, muscles, ligaments, shoes, the kind of riding they do, the type of pavement they ride in, the weather they ride in,whether they do vert skating or "transition" (ramps/bumps), rails, massive jumps, ground tricks, carving, downhill bombs, long distance push, pumping, etc etc, and even the way their mind works in relation to their body.

    so the amorphous concept of "feel" is, basically, everything on a skateboard. the top end skateboarding engineers like Paul Schmitt ( https://www.youtube.com/watch?v=18MRZq0bhpE ) will spend endless hours interacting with skateboarders to get continuous feedback about anything from wheel chemistry to changes in board shape. There is another interview there with rider Andy Anderson where he talks about how they shaved part of the sides of his board down in a slight taper so that it would be balanced evenly due to one side being slightly differently shaped than the other. To a casual watching him at the Olympics, you could not even tell which side of this board was front and back let alone if the sides had gotten tapered. That was just one many things he had put into the design of his board, all tailored around the style he wanted to skate (which is a lot of older freestyle like Primo and pogo hops combined with all the newer olympics stuff ).

    im sure there is some room to innovate trucks but it takes a lot of back and forth with a rider, its not , like the cat food can thing, a single variable optimization.

  • by fractalf on 9/26/22, 6:15 AM

    Interesting article. There is no mentioning of the art of Slalom Skateboarding, one of the absolute oldest styles of skateboarding. In this style the truck design is absolute critical. Still use the same basic design, but with adjustable angles and very short hangers. Also we keep a bag of different bushings to tune the board to different track setups. Check out G.O.G. trucks, the absolute undesputed best trucks for slalom skateboarding. Also Don't Trip makes good trucks for this style
  • by aboodman on 9/26/22, 3:57 AM

    The answer is that turn precision just isn’t important to street skaters. Many ride their trucks absurdly tight anyway. They aren’t turning by leaning very often. Other capabilities are far more important: durability, cost, grindability, etc.
  • by alkonaut on 9/25/22, 10:22 PM

    > I was tempted to think that these were just glaring, negligent design errors.

    As a software developer, luckily I always find out very quickly why designs aren’t as bad as they might seem at first sight. You just delete the seemingly negligent design, substitute your own, and wait for the reports of the regressions. Then in a hurry substitute back the original design, with an additional comment.

    Software development is easy.

  • by tablespoon on 9/26/22, 2:15 PM

    > What’s the Catch?

    > As I researched deeper without finding a satisfactory explanation, I was tempted to think that these were just glaring, negligent design errors. But I hesitated to come to such a strong conclusion.

    A huge amount of noise in internet comments (especially HN) is driven by people who give in to that temptation, and jump to self-aggrandizing criticism.

    > I love this tweet about a math professor who wrote a letter to Carnation, a canned cat food manufacturing company. He wrote to explain how they could optimize their can geometry for lower costs – it’s a classic calculus problem to find the optimal cylinder dimensions to minimize surface area-to-volume ratio. The company wrote back, but not to praise his insight. They kindly explained 5 other, obscure factors for the can’s design that he hadn't considered. Unlike calculus class, in the real world there are very few one-dimensional optimization problems.

    IMHO, when you have an opinion, it's more fruitful to think about the factors you missed in your analysis.

  • by gumby on 9/25/22, 11:06 PM

    > I suspected my question was similar - I noticed these two glaring flaws, but there are likely other, less obvious factors that contribute to the TKP design. So here are my speculations.

    I love that the author acknowledges Chesterton's Fence.

  • by an1sotropy on 9/26/22, 6:02 AM

    I haven’t seen mention here of suspension trucks https://avenuetrucks.com/ These replace the pivot with a very stiff spring, while still having a (floating) king-ish pin and grommets. The spring means there’s no single pivot axis, so I’m not sure how to apply the author’s analysis; does anyone else know?

    The feel is definitely different, but welcome on my geriatric knees. I learned about them from this video: https://youtu.be/8_ZaUQTU8k0

  • by Grustaf on 9/26/22, 8:49 AM

    I don’t think there is any athletic endeavor where people care less about “optimizing performance” than in skateboarding, especially in street. Partly because there is no sport or game where the equipment matters less (not even beginners think that getting another board will perceptibly improve there riding), but also because it’s almost a point of pride to be able to ride in suboptimal conditions.

    It’s not supposed to be easy. Even riding in shorts is sort of frowned upon. Most people don’t use helmets and riding an old banged up board with noisy bearings is way cooler than using a fresh new one.

  • by mrcartmeneses on 9/26/22, 7:55 AM

    The answer is simply that the “wasted” rebound is wasted deliberately. In other words this isn’t “waste” it’s dampening
  • by s5300 on 9/25/22, 11:00 PM

    3 Link (no kingpin) trucks are cool

    forum.esk8.news

    https://stoogeraceboards.com/collections/all

  • by skywhopper on 9/25/22, 11:54 PM

    In a scenario like this, it’s almost always a mistake to assume that the things you are measuring map directly to what the users “feel”. Sure, there may be some superstition involved, but however the skaters describe what they like or dislike about certain designs, you shouldn’t assume the measurement you are making maps to that property.
  • by iainctduncan on 9/27/22, 3:58 AM

    Independent makes really wide TKP trucks, so you can feel the difference by putting them on the same deck and wheels as similarly sized RKP. They feel very different. On TKP the first part of the turn is really fast, and then it becomes harder to make the rest of the turn. This is really good for breaking out into stand up slides, but scary if you're going fast. When I was mucking with them, a buddy who is a much better rider than me but hadn't tried wide TKPs was amazed at how much easier it was to do heelside slides, but we both agreed -- way too scary at speed. For park tricks though, that super fast first pump is a feature. I don't buy that it's about weight or grinding, I'm sure it's the turn.

    And then there are esoteric designs like double kingpin!

  • by sails on 9/26/22, 10:56 AM

    Here is an example of the racing that the cutting edge or RKP trucks are optimised for. Extremely narrow slalom trucks for high speed racing is a relatively recent development.

    https://www.youtube.com/watch?v=XR08HEiYPFA

  • by dn3500 on 9/26/22, 12:25 AM

    He should read up on steering geometry in general. The wheel axis always needs to be offset from the pivot axis or the steering will be unstable. Take a look at your bicycle and you'll see that the axle of the front wheel is at an offset from the steering axis, because the fork is curved (or offset).
  • by sopooneo on 9/26/22, 4:00 AM

    Not sure about dividing the force compressing the bushings into Fuseful and Fwasted. I may be misunderstanding, but it seems the Fwasted vector component just gets some mechanical advantage in compressing the bushing, and disadvantage on the restoring force.

    But that actually balances out fine. Is the claim that some of the work in compressing the bushing is never given back in energy restoring the truck to neutral?

  • by esseeayen on 9/26/22, 2:23 AM

    Hmm I was curious about the durability part when comparing the trucks. As an ex-skateboarder (lies I still ride around for fun but tricks are hard on my older body) I can say my trucks typically “grinded” away in the middle from, well, grinding. The only breaks haven’t been around the kingpin but more on the sides of the “T” near the wheels.
  • by emmelaich on 9/26/22, 1:13 AM

    I'm sorta surprised that trucks are cast. When I skateboarded the alternative truck was stamped metal, from Bahne.

    I believe they're stronger for the weight and less likely to fail catastrophically.

  • by impoppy on 9/26/22, 12:22 AM

    Not on topic, but the author uses an annoying mix of inline links and footnotes. Why aren’t they consistent on it I wonder