Speed wobble is a quick (4–10 Hz) oscillation of primarily just the steerable wheels of a board. Initially, the rest of the board remains mostly unaffected, until translated into a board yaw oscillation of increasing amplitude producing a loss of control. The initial instability occurs mostly at high speed. For starters, speed wobble on an electric skateboard can be caused by a number of different reasons.
Reason 1： Loose trucks
On the one hand, loose trucks can give you the too much-turning ability, making your settings super-responsive at any speed over 10-20 mph, but on the other, you may encounter speed wobble due to truck's violent swing. So if you drive faster than 10mph, you need to tighten your truck. How much depends on how fast you want to go and what bushings you’re riding. Adjust the trucks to where it is comfortable for you, then you can leave it alone unless you feel the trucks are abnormal.
Reason 2： The front truck is tighter than rear truck
If your front truck is tighter than the rear truck that means your rear truck will turn more than the front truck, which will cause the rear truck to start a violent fishtail and throw you off the board. So you need to keep the trucks at the same tightness or make the rear truck tighter than the front truck.
Reason 3： Your board is too tall for how loose your trucks are
Since top-mount boards are taller than drop-deck boards. The top-mount board has more turning ability due to more leverage on your trucks. When the top mount already degrades board stability, you need to replace it with a lower degree truck or having a more restrictive bushing setup, which will lead to a better riding experience on a top-mount board.
Reason 4： Improper weight displacement
Some beginners may make a common mistake that putting all their weight on the rear part of the board. However, exerting more weight on the rear truck means more pressure on bushings, which will cause more turning on the rear truck and less turning on the front truck, which does the same thing as having a looser back truck than the front. In fact, the front truck and wheels are the key parts on steering and it does no good to board stability if the rear truck has much more turning ability.
Therefore, you need to transfer the turning ability from the rear truck to the front by putting most of your weight on the front end of the board rather than on the back end.
Reason 5: Wrong foot placement
A lot of beginners places their front in the center of the board then places their back foot over the back truck. Place your front foot as far forward as possible without hanging your toes or heel over the railing. Preferably, place your footy at a 45-degree angle and your back foot about shoulder-width or more away from your front foot in between 45 and 90 degrees.
Speed wobble occurs mostly at high speed, such as riding down the hill. So here are some tips to prevent it when you are riding down the hill.
*Bend your knees to where it is comfortable for you, as you start to ride down the hill.
*Lean toe-side to heel-side to toe-side to heel-side. This is also referred to as carving.
*When you can tell that your board is starting to go faster, bend your front knee slightly more than your other, gaining 90% of your weight on your front foot.
*Watch out for cracks in the road, but don't get nervous and concentrate on what your ankles are doing, instead just look up ahead.