Skateboard geometry: balance line
The basic idea I’d like to convey with this post is that a skateboard always balances on the line that connects the two centers of the axles of the trucks. Continue reading Skateboard geometry: balance line
Category: Math
Ideal truck angles
How do we decide which angles our trucks should be wedged to? In a post addressed to beginners, I propose a process and explain the reasoning behind it. Continue reading Ideal truck angles
Wheelbase: the case for short decks
In this post, I want to make the case for a turn to shorter decks. First, I explain why long decks are redundant, then I enumerate the advantages of short-wheelbase decks and finally I attempt to answer exactly how short decks should/could become. Continue reading Wheelbase: the case for short decks
Pivot axis angles and wheelbase (open access)
Wheelbase and truck angles are directly related. I want to show that the three variables: front and rear angles and wheelbase are sufficient and necessary to determine the turning radius of a skateboard, when tilted a given amount. Continue reading Pivot axis angles and wheelbase (open access)
Truck geometry (open access)
Using logic, one can realize that every truck (with a single pivot) turns the same, regardless of rake or any other characteristic. This and a few other points about truck geometry are tackled in this post. Continue reading Truck geometry (open access)
Skateboard physics: wheel lift
In this post, I argue it’s essentially the difference in stiffness between the rear and front truck that causes wheel-lift. A shorter axle makes wheel lift more probable by placing the possible axis of rotation (of the wheel-lift) closer to the middle of the board (and therefore the rider’s weight further out from that axis). However, balanced front-rear truck stiffness would make wheel lift impossible, by placing that axis entirely out of reach for the rider’s weight. Continue reading Skateboard physics: wheel lift
Skateboard physics: moment of inertia
Understanding which forces are at play when the axle rotates on the ground is a pesky problem of mine. The goal is to obtain a good understanding of the effect that different axle lengths have when turning (an effect that’s overstated, I feel, in the community). It turns out the problem is not so unattackable. In this post, I report what I’ve found so far. Continue reading Skateboard physics: moment of inertia
Skateboard physics: squeezing bushings
Occasionally, people assert that TKP trucks (i.e., trucks with significant forward rake) turn “progressively,” while RKP trucks (i.e., trucks with minimal rake) turn more “linearly”. That, at first glance, can only mean that the trucks resist turning in such ways. In this post, I check for patterns in the way trucks resist when a rider leans on a skateboard. Continue reading Skateboard physics: squeezing bushings
Board height: does it matter?
Why I think board height doesn’t matter (in absolute terms – i.e., efficiency, acceleration etc) and if it did, lower would be better. The “top mount offers more leverage over the trucks” argument is void. The rider on a dropped … Continue reading Board height: does it matter?
Rear hanger width: does it matter?
“Get a narrow rear” is often given as advice in internet communities for LDP. Is this a relic of the dark ages of skateboard geekery, or is there a valid LDP/slalom-related reason behind it? I investigate. Continue reading Rear hanger width: does it matter?
Skateboard physics: one-spring truck (and the dead-zone problem)
In this entry I want to write down a couple of things that relate to a project that might or might not happen in the future. It’s an idea by a friend (whose handle is “Holden”), who already built a few two-spring trucks. His dream was (still is) to built a one-spring truck. Continue reading Skateboard physics: one-spring truck (and the dead-zone problem)
Turning radius: as a function of the rear PA angle
This post is to show, in very practical terms and without abstract models, that reversing the rear truck is simply an option available for when we need it, not some fanciful eccentricity. I derive a very simple rule-of-thumb for those keen to experiment. Continue reading Turning radius: as a function of the rear PA angle
Changing Angles 