HOW TO ASSEMBLE AND MAINTAIN YOUR BOARD
A Guide To Longboard Assembly and Tuning
By Alex Kwiecinski
Founder, Go Green Longboarding
This guide is intented to answer frequently asked questions, and to help people properly install equipment on thier longboards. If you plan on taking longboarding seriously, take the time to read this in detail. It took me a decade of skateboarding and several years of longboarding to gain this knowledge, so it may take a long time to understand all of the information here. Only adjust one thing on your board at a time so you can study the effects in a scientific approach, and read instructions before performing a task to make sure you have an idea of what you’re doing. If you want to go one step farther than this manual you can make your own decks. For tutorials on how to make longboard decks, see www.silverfishlongboarding.com.
Most decks are purpose specific. Speed boards are usually long and stiff, slalom boards are usually short and stiff, slide boards are usually similar to park skateboards, etc. However, there are key attribures to take into mind when choosing a longboard that will effect how your board rides.
Many deck companies list wheelbase as the distance between the closest mounting screws of the baseplates. The wheelbase is actually the distance between the centers of the axels, and switching trucks may change that distance. Simply put, boards with short wheelbases (especially under 30″) have tigher turning radiuses, and boards with longer wheelbases have larger turning radiuses. Decks with short wheelbases also have a lower minimum speed to start “pumping” for speed. Disregarding flex as a factor, longer boards will be more stable.
Stiffness and Flex
Stiffer boards are better for riding at higher speeds. Flexy boards are used primarliy for pumping or fun transportation boards. Most of todays speedboarders, slalom riders, and sliders usually ride stiff decks. A flexy deck will result in explosive turns and pumping, and the more the board flexes, the tigher the turning radius is at that time. It’s basically like wedging the trucks every time you turn- it’s fun at low speeds, but not-so-fun or even dangerous on race boards. Flex can also make it more difficult to control the release and ending points of slides, but in most cases if the riders feet are placed close to the trucks this can be overcome. An advantage to flex is it will allow a long wheelbase board to turn in a relatively tight area, given the rider doesn’t need to handle high speeds on that board.
Concave and Torsion
Torsion is the ability of a given deck to “twist”. I don’t know of a situation where torsional flex could be an advantage; If your deck can twist easily, this almost entirely defeats the purpose of setting your truck angles. That being said, concave does help to eliminate torsion on boards, but concave also makes some boards (slalom especially) less responsive in quick turning situations. I personally ride both concave and flat boards. Most flat boards will be designed to avoid torsional flex, but if you’re riding an old piece of wood, you might want to check it.
For the purpose of discussing turning geometry, I’m only going to cover reverse kingpin trucks such as Randal, Bear, and Crail here. Conventional trucks are fine on park, slalom, and slide setups, and proper steering can be acheieved through the exact same wedging and bushing hardness techinques that I will discuss below.
Quick Turn vs. Stable Turn Geometry, and Eliminating Slop
To determine the steering angle on reverse kingpin trucks, measure the angle at which the hanger sits in relation to the bottom of the board. Assuming the board is not cambered and wedges are not installed, a Randal II baseplate sits at a 50 degree angle, resulting in a quick turning geometry. Crail trucks and Seismic quick turning trucks sit at a 45 degree angle. This means when the rider leans toward one wheel, the wheel should steer the same distance toward the center of the deck as it travels toward the deck iteself. This is great for sharp turns, but if both trucks are at this angle, traction and stability will be non-existant at high speeds. A 30 degree baseplate which allows the wheel to travel the same distance toward the deck would not steer the wheel nearly as far toward the center of the deck. This results in much greater traction, but lowered steering ability. Wedging can be used to change the steering angle of a truck.
Sadly, this is in an ideal world without the slop of bushings and pivot cups. If you grab the hanger of almost any board with mounted reverse kingpin trucks, you can phsically move the truck in ways that are not along the correct steering path. This can result in a loss of stability or traction, or both. This is why some companies like Bear Trucks and JimZ Speedparts are introducing a sperical bearing between the bushings, and more precise piviot points to help eliminate slop. Seismic makes affordable trucks with springs along the steering path, and baseplates (in both 45 and 30 degree models) that virtually eliminate slop from this path. Eliminating slop makes your trucks steer at the right angle regardless of the turn you’re making, and this means one thing: more traction. Slalom and speedboard racers are especially concerned with eliminating slop, because what racer doesn’t want more traction?
Note: One thing to keep in mind is that narrower hangers are quicker turning than wider hangers. Usually you won’t have to worry too much about this unless you find yourself up on two wheels frequently. In that case you’ll need wider hangers and/or softer bushings.
Wedging refers to the use of angled risers on ‘top-mount’ (board on top of the truck) boards. With both normal and reverse kingpin trucks, if the thinner part of the wedge is under the pivot cup of the truck, the truck is wedged, and will steer as if it has a higher angled baseplate. If the Thicker part of the wedge is placed under the pivot cup, this will “de-wedge” the truck and cause it to become more stable. In other words, de-wedging a truck will make it act more like a 30 degree basplate than a 50.
When wedging and de-wedging, make sure you’re not going to end up making one axel sit way higher than the other (by andrew). Add thin flat risers if need be to remedy this situation. This is another situation where seismic trucks are great, because you can use a 45 degree truck on the front with a 30 degree truck on the back and have the exact same axel height without the use of wedging or risers.
Traction and Turning Via Geometry and Bushings
When setting up a board for higher speeds, geometry becomes incredibly important. On speed boards and especially slalom boards, it is almost mandatory to de-wedge the back truck to make it more stable. This allows for better grip through turns, and better stability at high speeds. Slalom boarders and some speed boarders will wedge the front truck to gain a tighter turning radius. The only times I leave both trucks at their stock steering angle, or wedge both trucks, are on incredibly long boards (longer boards have wider turning radiuses), slide boards, or low speed transportation boards. In these cases I use softer bushings in the front truck than in the back to make the board steer in a better geometry.
As far as bushings go, I ride the softest ones I can in the front truck that don’t allow the wheels to “bite” (hit the bottom of the deck). If the back truck is de-wedged, I usually follow the same guideline for those bushings, or maybe go a little bit stiffer. As said before, if your trucks are at the same geometry, you’ll probably want stiffer bushings on the back truck. This is to avoid feeling like you’re driving a car in reverse (that’s what it feels like if the back truck out-steers the front truck, and it is BAD!)
Kingpins and Truck Mounting
When mounting a baseplate to a deck, I recommend using an 1/8″ shock pad to prevent stress cracks to your deck if you’re not using wedges. With wood decks, tighten the screws untill the tops are flush with your grip tape. If the baseplate becomes loose, tighten them a little bit more. If you’ve got a board with a fiberglass or composite topsheet and you don’t want to counter-sink your screws, use round top screws with a washer. However, if your deck allows you to stand right on your trucks, you’ll have to not mind stepping on these screws.
The kingpins that come stock in randal trucks are 2.5″ long. If you want to run a different brand of bushings, you may need a bigger kingpin. for reverse kingpin trucks, I recommend using all full-barrel (“big”) bushings, and flat washers, on a 3″ long, grade-8, size 3/8″ bolt (wrench size 9/16″).
Make sure the bushing/washer combo you’re using between the hanger and baseplate measures the same thickness as the stock bushing/washer combo. If it’s different it will affect your steering geometry, and that’s the best case scenario. I also recommend buying a kit of different durometer bushings so you can properly change the feel of a truck without having to over-tighten your kingpin. If I use two different durometer bushings of the same shape on a truck, I put the harder of the two between the hanger and baseplate to prevent the hanger from changing geometry when I tighten the kingpin. This is a personal preference based on the many boards I’ve assembeled.
When you’re installing bushings, tighten the kingpin till it’s just barely snug (i.e. there’s no visible slop). Give it a couple of turns from there, and see where you’re at. If the board doesn’t lean enough, you’ll definately need softer bushings. If any of the wheels hit the bottom of the deck easliy, you’ll need harder bushings. If the wheel hits, but not easily, you can try tightening that truck. If you can’t fix it without wrenching the bolt down excessively, put in harder bushings.
Wheels have 3 important factors to consider. These are size, durometer, and bearing seat.
Longboard wheels range anywhere from 60mm to nearly 100mm in diameter, so choosing the right size is important. As a general guideline, bigger wheels are faster, due to their ability to roll over rough survces, and due to the fact that they physically spin the bearing less per unit of distance traveled. With downhill skating, once you’re over 70mm, the grade of the hill will determine how fast you’re going to go almost completely regardless of wheel size.
Durometer refers to how hard the urethane is that the wheel is made out of. Different companies have different formulas, but regardless of those differences, the durometer scale is a good way to judge how soft or hard a wheel will be. 70a wheels would be extremely soft, and most companies start around 75a hardness. 75a-82a wheels are soft and have great traction. Above this, wheels start getting harder and are usually for park or slide use. 90a-100a wheels are extremely hard, and thus accelerate and slide much faster than softer wheels. Wheels this hard have exponentially less traction, especially on rough pavement.
Bearing Seat and Spacing
“Center set” means that the bearings sit dead centered in the wheel, and the wheel is reversable without effect to how it rides. “Sideset” bearing seats sit all the way to the inside of the wheel, resulting in better traction, but in my personal opinion, a small loss in speed. You also lose the option to “flip” the wheel if it starts to wear unevenly or cone. “Offset” bearing seats sit between center set and side set geometry, resulting in a fast wheel with good traction, but these wheels are not usually designed to be reversable.
Most skateboard and longboard wheels have a gap of 10mm between the bearings, and spacers should be placed between the bearings during installation. Some wheels require 8mm spacers (Kryptonics classics and certain Gravity wheels for example), so if your bearings don’t go all the way in with a 10mm spacer in place, this is why. Always use bearing spacers, otherwise you’re losing speed, smashing your bearing shields, and it’s impossible to properly tighten your wheel nuts. If you don’t have spacers and you overtighten your wheel nuts, you can literally melt the core of your wheel.
Mounting and Rotation
After you’ve installed your bearings with spacers between them, slide one speed ring onto the axel, slide the wheel on (it may require patience to properly align the spacer), and install the other speed ring. Start threading the wheel nut, and tighten the nut with a ratchet just untill the wheel cannot be moved side to side on the axel anymore. You should feel the wrench just “stop” turning at this point, DO NOT FORCE IT ANY TIGHTER. If everything is good, your wheel should spin freely without any side to side play (you may need to loosen the wheel nut just a touch, and that’s ok so long as you can’t slide the wheel back and forth on the axel at all). If your wheel seems restricted, or if you think your bearings aren’t seated properly, push the wheel both ways on the axel with an even amount of force, then loosen and re-tighten the wheel nut.
Wheels should be rotated in an x-pattern (front left wheel to back right, etc.) after they start to wear, or after hours of intense riding. If you have center set wheels and they’re starting to “cone”, flip the logos around when you rotate your wheels. This will allow them to wear evenly.
Skatepark or slide boards: Generally you should use 60-65mm diameter wheels in a hard (90’s) durometer. Center set bearing seats are preferrable so you can rotate your wheels properly. In my experience, wider contact patches make for longer slides, and if nothing else they’ll make your s
-Mike Dallas and Alex K. of Go Green Longboarding, Michigan