Truck Technology

In 1993, Seismic patented one of the most original and sophisticated technologies ever developed for skateboarding. The first of the new generation of longboard trucks, it was so far ahead of its time that even we had to poke fun at it in our September 1994 <em>TransWorld Skateboarding</em> ad! But soon enough, our spring-loaded design inspired cheap imitations in off-road skateboards and surfing cross-trainers.

Redesigned in 2003 and again in 2015, the Seismic spring truck technology now offers impressive tuning options for the discerning skater, and advanced performance for longboarding, racing, all-purpose cruising, Old School park/pool styling, and snow/surf cross-training.

SHOP TRUCKS

Truck Design & Engineering

Truck Axle Tolerance

Seismic axles (both G5 and Aeon) are manufactured to be 7.95mm in diameter, with a small negative-only tolerance. Racing truck makers who advertise “true 8.0mm axles” generally follow a similar specification. Average brands use 5/16-inch (7.9375mm) axles.

The inner race of standard wheel bearings has a diameter of 8.0mm, with a small manufacturing tolerance. Truck axles need to have a diameter slightly smaller than that, or else some bearings may not fit or even get stuck.

Truck Hole Pattern

Seismic trucks (both G5 and Aeon) support both “Old School” and “New School” mounting hole patterns. In the case of the G5, this was a significant engineering challenge given the truck’s unique structure.

The Old School mounting hole pattern has holes that are 2.50″ (63.5mm) center-to-center longways. In the New School hole pattern, that distance is only 53.5mm (2.11″). Both patterns have holes that are 1.625″ center-to-center sideways.

Spring Selection

Seismic springs come in seven (7) different color-coded strengths. The standard pre-installed springs are designed to optimally blend turning ease, stability and resilience for the average user. Of course, what works best for you will vary depending on size, style, personal preferences, and the disciplines you practice.

The Seismic metal coil springs’ rapid energy return capitalizes on your thrust-carving action more efficiently than traditional urethane bushings (which are basically primitive damping springs). The quicker the board rights itself after you unweight, the stronger you can pump. For more stability, increase spring tension, buy heavier springs, or switch to the stable-turning baseplate. For more maneuverability, decrease spring tension, try lighter springs, or switch to the quick-turning baseplate.

<strong>For super specific recommendations, view our body weight charts:</strong>

75 lbs / 34 kg

<table id=”weightChart” style=”height: 341px;”>
<tbody>
<tr>
<td id=”weightChart” class=”header” colspan=”4″>75 lbs / 34 kg</td>
</tr>
<tr class=”subheader”>
<td id=”title_left2″ align=”left” valign=”top” width=”173″>Discipline</td>
<td id=”title_left2″ align=”left” valign=”top” width=”108″>Truck</td>
<td id=”title_left2″ align=”left” valign=”top” width=”155″>Geometry</td>
<td id=”title_left2″ align=”left” valign=”top” width=”206″>Spring Strength</td>
</tr>
<tr>
<td id=”title_left2″ rowspan=”2″>Street / Freestyle</td>
<td id=”left2″ align=”left” valign=”top”>Front</td>
<td id=”left2″ align=”left” valign=”top”>30°</td>
<td id=”left2″ align=”left” valign=”top”>Super-Light or Extra-Light</td>
</tr>
<tr>
<td id=”left2″ align=”left” valign=”top”>Rear</td>
<td id=”left2″ align=”left” valign=”top”>30°</td>
<td id=”left2″ align=”left” valign=”top”>Super-Light or Extra-Light</td>
</tr>
<tr>
<td id=”title_left2″ rowspan=”2″>Park / Pool</td>
<td id=”left2″ align=”left” valign=”top”>Front</td>
<td id=”left2″ align=”left” valign=”top”>45°</td>
<td id=”left2″ align=”left” valign=”top”>Max-Light</td>
</tr>
<tr>
<td id=”left2″ align=”left” valign=”top”>Rear</td>
<td id=”left2″ align=”left” valign=”top”>30°</td>
<td id=”left2″ align=”left” valign=”top”>Super-Light</td>
</tr>
<tr>
<td id=”title_left2″ rowspan=”2″>Ramp</td>
<td id=”left2″ align=”left” valign=”top”>Front</td>
<td id=”left2″ align=”left” valign=”top”>30° or 45°</td>
<td id=”left2″ align=”left” valign=”top”>Super-Light</td>
</tr>
<tr>
<td id=”left2″ align=”left” valign=”top”>Rear</td>
<td id=”left2″ align=”left” valign=”top”>30°</td>
<td id=”left2″ align=”left” valign=”top”>Extra-Light</td>
</tr>
<tr>
<td id=”title_left2″ rowspan=”2″>Longboard</td>
<td id=”left2″ align=”left” valign=”top”>Front</td>
<td id=”left2″ align=”left” valign=”top”>45°</td>
<td id=”left2″ align=”left” valign=”top”>Max-Light</td>
</tr>
<tr>
<td id=”left2″ align=”left” valign=”top”>Rear</td>
<td id=”left2″ align=”left” valign=”top”>30° (performance)
45° (recreation)</td>
<td id=”left2″ align=”left” valign=”top”>Super-Light</td>
</tr>
<tr>
<td id=”title_left2″ rowspan=”2″>Slalom</td>
<td id=”left2″ align=”left” valign=”top”>Front</td>
<td id=”left2″ align=”left” valign=”top”>45°</td>
<td id=”left2″ align=”left” valign=”top”>Max-Light</td>
</tr>
<tr>
<td id=”left2″ align=”left” valign=”top”>Rear</td>
<td id=”left2″ align=”left” valign=”top”>30° (performance)
45° (recreation)</td>
<td id=”left2″ align=”left” valign=”top”>Super-Light</td>
</tr>
<tr>
<td id=”title_left2″ rowspan=”2″>Downhill</td>
<td id=”left2″ align=”left” valign=”top”>Front</td>
<td id=”left2″ align=”left” valign=”top”>30°</td>
<td id=”left2″ align=”left” valign=”top”>Light</td>
</tr>
<tr>
<td id=”left2″ align=”left” valign=”top”>Rear</td>
<td id=”left2″ align=”left” valign=”top”>30°</td>
<td id=”left2″ align=”left” valign=”top”>Light</td>
</tr>
</tbody>
</table>

100 lbs / 45 kg

<table id=”weightChart”>
<tbody>
<tr>
<td class=”header” colspan=”4″>100 lbs / 45 kg</td>
</tr>
<tr class=”subheader”>
<td id=”title_left3″ align=”left” valign=”top”>Discipline</td>
<td id=”title_left3″ align=”left” valign=”top”>Truck</td>
<td id=”title_left3″ align=”left” valign=”top”>Geometry</td>
<td id=”title_left3″ align=”left” valign=”top”>Spring Strength</td>
</tr>
<tr>
<td id=”title_left3″ rowspan=”2″>Street / Freestyle</td>
<td id=”left3″ align=”left” valign=”top”>Front</td>
<td id=”left3″ align=”left” valign=”top”>30°</td>
<td id=”left3″ align=”left” valign=”top”>Extra-Light or Light</td>
</tr>
<tr>
<td id=”left3″ align=”left” valign=”top”>Rear</td>
<td id=”left3″ align=”left” valign=”top”>30°</td>
<td id=”left3″ align=”left” valign=”top”>Extra-Light or Light</td>
</tr>
<tr>
<td id=”title_left3″ rowspan=”2″>Park / Pool</td>
<td id=”left3″ align=”left” valign=”top”>Front</td>
<td id=”left3″ align=”left” valign=”top”>45°</td>
<td id=”left3″ align=”left” valign=”top”>Super-Light</td>
</tr>
<tr>
<td id=”left3″ align=”left” valign=”top”>Rear</td>
<td id=”left3″ align=”left” valign=”top”>30°</td>
<td id=”left3″ align=”left” valign=”top”>Extra-Light</td>
</tr>
<tr>
<td id=”title_left3″ rowspan=”2″>Ramp</td>
<td id=”left3″ align=”left” valign=”top”>Front</td>
<td id=”left3″ align=”left” valign=”top”>30° or 45°</td>
<td id=”left3″ align=”left” valign=”top”>Extra-Light</td>
</tr>
<tr>
<td id=”left3″ align=”left” valign=”top”>Rear</td>
<td id=”left3″ align=”left” valign=”top”>30°</td>
<td id=”left3″ align=”left” valign=”top”>Light</td>
</tr>
<tr>
<td id=”title_left3″ rowspan=”2″>Longboard</td>
<td id=”left3″ align=”left” valign=”top”>Front</td>
<td id=”left3″ align=”left” valign=”top”>45°</td>
<td id=”left3″ align=”left” valign=”top”>Max-Light or Super-Light</td>
</tr>
<tr>
<td id=”left3″ align=”left” valign=”top”>Rear</td>
<td id=”left3″ align=”left” valign=”top”>30° (performance)
45° (recreation)</td>
<td id=”left3″ align=”left” valign=”top”>Super-Light or Extra-Light</td>
</tr>
<tr>
<td id=”title_left3″ rowspan=”2″>Slalom</td>
<td id=”left3″ align=”left” valign=”top”>Front</td>
<td id=”left3″ align=”left” valign=”top”>45°</td>
<td id=”left3″ align=”left” valign=”top”>Max-Light or Super-Light</td>
</tr>
<tr>
<td id=”left3″ align=”left” valign=”top”>Rear</td>
<td id=”left3″ align=”left” valign=”top”>30° (performance)
45° (recreation)</td>
<td id=”left3″ align=”left” valign=”top”>Super-Light or Extra-Light</td>
</tr>
<tr>
<td id=”title_left3″ rowspan=”2″>Downhill</td>
<td id=”left3″ align=”left” valign=”top”>Front</td>
<td id=”left3″ align=”left” valign=”top”>30°</td>
<td id=”left3″ align=”left” valign=”top”>Light or Medium</td>
</tr>
<tr>
<td id=”left3″ align=”left” valign=”top”>Rear</td>
<td id=”left3″ align=”left” valign=”top”>30°</td>
<td id=”left3″ align=”left” valign=”top”>Light or Medium</td>
</tr>
</tbody>
</table>

125 lbs / 57 kg

<table id=”weightChart” style=”width: 100%;” border=”0″ cellspacing=”0″ cellpadding=”5″>
<tbody>
<tr>
<td class=”header” colspan=”4″>125 lbs / 57 kg</td>
</tr>
<tr class=”subheader”>
<td id=”title_left4″ align=”left” valign=”top”>Discipline</td>
<td id=”title_left4″ align=”left” valign=”top”>Truck</td>
<td id=”title_left4″ align=”left” valign=”top”>Geometry</td>
<td id=”title_left4″ align=”left” valign=”top”>Spring Strength</td>
</tr>
<tr>
<td id=”title_left4″ rowspan=”2″>Street / Freestyle</td>
<td id=”left4″ align=”left” valign=”top”>Front</td>
<td id=”left4″ align=”left” valign=”top”>30°</td>
<td id=”left4″ align=”left” valign=”top”>Light or Medium</td>
</tr>
<tr>
<td id=”left4″ align=”left” valign=”top”>Rear</td>
<td id=”left4″ align=”left” valign=”top”>30°</td>
<td id=”left4″ align=”left” valign=”top”>Light or Medium</td>
</tr>
<tr>
<td id=”title_left4″ rowspan=”2″>Park / Pool</td>
<td id=”left4″ align=”left” valign=”top”>Front</td>
<td id=”left4″ align=”left” valign=”top”>45°</td>
<td id=”left4″ align=”left” valign=”top”>Super-Light or Extra-Light</td>
</tr>
<tr>
<td id=”left4″ align=”left” valign=”top”>Rear</td>
<td id=”left4″ align=”left” valign=”top”>30°</td>
<td id=”left4″ align=”left” valign=”top”>Extra-Light or Light</td>
</tr>
<tr>
<td id=”title_left4″ rowspan=”2″>Ramp</td>
<td id=”left4″ align=”left” valign=”top”>Front</td>
<td id=”left4″ align=”left” valign=”top”>30° or 45°</td>
<td id=”left4″ align=”left” valign=”top”>Extra-Light or Light</td>
</tr>
<tr>
<td id=”left4″ align=”left” valign=”top”>Rear</td>
<td id=”left4″ align=”left” valign=”top”>30°</td>
<td id=”left4″ align=”left” valign=”top”>Light or Medium</td>
</tr>
<tr>
<td id=”title_left4″ rowspan=”2″>Longboard</td>
<td id=”left4″ align=”left” valign=”top”>Front</td>
<td id=”left4″ align=”left” valign=”top”>45°</td>
<td id=”left4″ align=”left” valign=”top”>Super-Light</td>
</tr>
<tr>
<td id=”left4″ align=”left” valign=”top”>Rear</td>
<td id=”left4″ align=”left” valign=”top”>30° (performance)
45° (recreation)</td>
<td id=”left4″ align=”left” valign=”top”>Extra-Light</td>
</tr>
<tr>
<td id=”title_left4″ rowspan=”2″>Slalom</td>
<td id=”left4″ align=”left” valign=”top”>Front</td>
<td id=”left4″ align=”left” valign=”top”>45°</td>
<td id=”left4″ align=”left” valign=”top”>Super-Light</td>
</tr>
<tr>
<td id=”left4″ align=”left” valign=”top”>Rear</td>
<td id=”left4″ align=”left” valign=”top”>30° (performance)
45° (recreation)</td>
<td id=”left4″ align=”left” valign=”top”>Extra-Light</td>
</tr>
<tr>
<td id=”title_left4″ rowspan=”2″>Downhill</td>
<td id=”left4″ align=”left” valign=”top”>Front</td>
<td id=”left4″ align=”left” valign=”top”>30°</td>
<td id=”left4″ align=”left” valign=”top”>Medium</td>
</tr>
<tr>
<td id=”left4″ align=”left” valign=”top”>Rear</td>
<td id=”left4″ align=”left” valign=”top”>30°</td>
<td id=”left4″ align=”left” valign=”top”>Medium</td>
</tr>
</tbody>
</table>

150 lbs / 68 kg

<table id=”weightChart”>
<tbody>
<tr>
<td class=”header” colspan=”4″>150 lbs / 68 kg</td>
</tr>
<tr class=”subheader”>
<td id=”title_left5″ align=”left” valign=”top”>Discipline</td>
<td id=”title_left5″ align=”left” valign=”top”>Truck</td>
<td id=”title_left5″ align=”left” valign=”top”>Geometry</td>
<td id=”title_left5″ align=”left” valign=”top”>Spring Strength</td>
</tr>
<tr>
<td id=”title_left5″ rowspan=”2″>Street / Freestyle</td>
<td id=”left5″ align=”left” valign=”top”>Front</td>
<td id=”left5″ align=”left” valign=”top”>30°</td>
<td id=”left5″ align=”left” valign=”top”>Medium</td>
</tr>
<tr>
<td id=”left5″ align=”left” valign=”top”>Rear</td>
<td id=”left5″ align=”left” valign=”top”>30°</td>
<td id=”left5″ align=”left” valign=”top”>Medium</td>
</tr>
<tr>
<td id=”title_left5″ rowspan=”2″>Park / Pool</td>
<td id=”left5″ align=”left” valign=”top”>Front</td>
<td id=”left5″ align=”left” valign=”top”>45°</td>
<td id=”left5″ align=”left” valign=”top”>Extra-Light or Light</td>
</tr>
<tr>
<td id=”left5″ align=”left” valign=”top”>Rear</td>
<td id=”left5″ align=”left” valign=”top”>30°</td>
<td id=”left5″ align=”left” valign=”top”>Light or Medium</td>
</tr>
<tr>
<td id=”title_left5″ rowspan=”2″>Ramp</td>
<td id=”left5″ align=”left” valign=”top”>Front</td>
<td id=”left5″ align=”left” valign=”top”>30° or 45°</td>
<td id=”left5″ align=”left” valign=”top”>Light or Medium</td>
</tr>
<tr>
<td id=”left5″ align=”left” valign=”top”>Rear</td>
<td id=”left5″ align=”left” valign=”top”>30°</td>
<td id=”left5″ align=”left” valign=”top”>Medium or Heavy</td>
</tr>
<tr>
<td id=”title_left5″ rowspan=”2″>Longboard</td>
<td id=”left5″ align=”left” valign=”top”>Front</td>
<td id=”left5″ align=”left” valign=”top”>45°</td>
<td id=”left5″ align=”left” valign=”top”>Extra-Light</td>
</tr>
<tr>
<td id=”left5″ align=”left” valign=”top”>Rear</td>
<td id=”left5″ align=”left” valign=”top”>30° (performance)
45° (recreation)</td>
<td id=”left5″ align=”left” valign=”top”>Light</td>
</tr>
<tr>
<td id=”title_left5″ rowspan=”2″>Slalom</td>
<td id=”left5″ align=”left” valign=”top”>Front</td>
<td id=”left5″ align=”left” valign=”top”>45°</td>
<td id=”left5″ align=”left” valign=”top”>Super-Light or Extra-Light</td>
</tr>
<tr>
<td id=”left5″ align=”left” valign=”top”>Rear</td>
<td id=”left5″ align=”left” valign=”top”>30° (performance)
45° (recreation)</td>
<td id=”left5″ align=”left” valign=”top”>Extra-Light or Light</td>
</tr>
<tr>
<td id=”title_left5″ rowspan=”2″>Downhill</td>
<td id=”left5″ align=”left” valign=”top”>Front</td>
<td id=”left5″ align=”left” valign=”top”>30°</td>
<td id=”left5″ align=”left” valign=”top”>Medium or Heavy</td>
</tr>
<tr>
<td id=”left5″ align=”left” valign=”top”>Rear</td>
<td id=”left5″ align=”left” valign=”top”>30°</td>
<td id=”left5″ align=”left” valign=”top”>Medium or Heavy</td>
</tr>
</tbody>
</table>

175 lbs / 79 kg

<table id=”weightChart”>
<tbody>
<tr>
<td class=”header” colspan=”4″>175 lbs / 79 kg</td>
</tr>
<tr class=”subheader”>
<td id=”title_left6″ align=”left” valign=”top”>Discipline</td>
<td id=”title_left6″ align=”left” valign=”top”>Truck</td>
<td id=”title_left6″ align=”left” valign=”top”>Geometry</td>
<td id=”title_left6″ align=”left” valign=”top”>Spring Strength</td>
</tr>
<tr>
<td id=”title_left6″ rowspan=”2″>Street / Freestyle</td>
<td id=”left6″ align=”left” valign=”top”>Front</td>
<td id=”left6″ align=”left” valign=”top”>30°</td>
<td id=”left6″ align=”left” valign=”top”>Medium or Heavy</td>
</tr>
<tr>
<td id=”left6″ align=”left” valign=”top”>Rear</td>
<td id=”left6″ align=”left” valign=”top”>30°</td>
<td id=”left6″ align=”left” valign=”top”>Medium or Heavy</td>
</tr>
<tr>
<td id=”title_left6″ rowspan=”2″>Park / Pool</td>
<td id=”left6″ align=”left” valign=”top”>Front</td>
<td id=”left6″ align=”left” valign=”top”>45°</td>
<td id=”left6″ align=”left” valign=”top”>Light or Medium</td>
</tr>
<tr>
<td id=”left6″ align=”left” valign=”top”>Rear</td>
<td id=”left6″ align=”left” valign=”top”>30°</td>
<td id=”left6″ align=”left” valign=”top”>Medium or Heavy</td>
</tr>
<tr>
<td id=”title_left6″ rowspan=”2″>Ramp</td>
<td id=”left6″ align=”left” valign=”top”>Front</td>
<td id=”left6″ align=”left” valign=”top”>30° or 45°</td>
<td id=”left6″ align=”left” valign=”top”>Medium</td>
</tr>
<tr>
<td id=”left6″ align=”left” valign=”top”>Rear</td>
<td id=”left6″ align=”left” valign=”top”>30°</td>
<td id=”left6″ align=”left” valign=”top”>Heavy</td>
</tr>
<tr>
<td id=”title_left6″ rowspan=”2″>Longboard</td>
<td id=”left6″ align=”left” valign=”top”>Front</td>
<td id=”left6″ align=”left” valign=”top”>45°</td>
<td id=”left6″ align=”left” valign=”top”>Extra-Light or Light</td>
</tr>
<tr>
<td id=”left6″ align=”left” valign=”top”>Rear</td>
<td id=”left6″ align=”left” valign=”top”>30° (performance)
45° (recreation)</td>
<td id=”left6″ align=”left” valign=”top”>Light or Medium</td>
</tr>
<tr>
<td id=”title_left6″ rowspan=”2″>Slalom</td>
<td id=”left6″ align=”left” valign=”top”>Front</td>
<td id=”left6″ align=”left” valign=”top”>45°</td>
<td id=”left6″ align=”left” valign=”top”>Extra-Light or Light</td>
</tr>
<tr>
<td id=”left6″ align=”left” valign=”top”>Rear</td>
<td id=”left6″ align=”left” valign=”top”>30° (performance)
45° (recreation)</td>
<td id=”left6″ align=”left” valign=”top”>Light or Medium</td>
</tr>
<tr>
<td id=”title_left6″ rowspan=”2″>Downhill</td>
<td id=”left6″ align=”left” valign=”top”>Front</td>
<td id=”left6″ align=”left” valign=”top”>30°</td>
<td id=”left6″ align=”left” valign=”top”>Heavy</td>
</tr>
<tr>
<td id=”left6″ align=”left” valign=”top”>Rear</td>
<td id=”left6″ align=”left” valign=”top”>30°</td>
<td id=”left6″ align=”left” valign=”top”>Heavy</td>
</tr>
</tbody>
</table>

200 lbs / 91 kg

<table id=”weightChart”>
<tbody>
<tr>
<td class=”header” colspan=”4″>200 lbs / 91 kg</td>
</tr>
<tr class=”subheader”>
<td id=”title_left7″ align=”left” valign=”top”>Discipline</td>
<td id=”title_left7″ align=”left” valign=”top”>Truck</td>
<td id=”title_left7″ align=”left” valign=”top”>Geometry</td>
<td id=”title_left7″ align=”left” valign=”top”>Spring Strength</td>
</tr>
<tr>
<td id=”title_left7″ rowspan=”2″>Street / Freestyle</td>
<td id=”left7″ align=”left” valign=”top”>Front</td>
<td id=”left7″ align=”left” valign=”top”>30°</td>
<td id=”left7″ align=”left” valign=”top”>Heavy or Extra-Heavy</td>
</tr>
<tr>
<td id=”left7″ align=”left” valign=”top”>Rear</td>
<td id=”left7″ align=”left” valign=”top”>30°</td>
<td id=”left7″ align=”left” valign=”top”>Heavy or Extra-Heavy</td>
</tr>
<tr>
<td id=”title_left7″ rowspan=”2″>Park / Pool</td>
<td id=”left7″ align=”left” valign=”top”>Front</td>
<td id=”left7″ align=”left” valign=”top”>45°</td>
<td id=”left7″ align=”left” valign=”top”>Medium or Heavy</td>
</tr>
<tr>
<td id=”left7″ align=”left” valign=”top”>Rear</td>
<td id=”left7″ align=”left” valign=”top”>30°</td>
<td id=”left7″ align=”left” valign=”top”>Heavy or Extra-Heavy</td>
</tr>
<tr>
<td id=”title_left7″ rowspan=”2″>Ramp</td>
<td id=”left7″ align=”left” valign=”top”>Front</td>
<td id=”left7″ align=”left” valign=”top”>30° or 45°</td>
<td id=”left7″ align=”left” valign=”top”>Heavy</td>
</tr>
<tr>
<td id=”left7″ align=”left” valign=”top”>Rear</td>
<td id=”left7″ align=”left” valign=”top”>30°</td>
<td id=”left7″ align=”left” valign=”top”>Extra-Heavy</td>
</tr>
<tr>
<td id=”title_left7″ rowspan=”2″>Longboard</td>
<td id=”left7″ align=”left” valign=”top”>Front</td>
<td id=”left7″ align=”left” valign=”top”>45°</td>
<td id=”left7″ align=”left” valign=”top”>Light or Medium</td>
</tr>
<tr>
<td id=”left7″ align=”left” valign=”top”>Rear</td>
<td id=”left7″ align=”left” valign=”top”>30° (performance)
45° (recreation)</td>
<td id=”left7″ align=”left” valign=”top”>Medium or Heavy</td>
</tr>
<tr>
<td id=”title_left7″ rowspan=”2″>Slalom</td>
<td id=”left7″ align=”left” valign=”top”>Front</td>
<td id=”left7″ align=”left” valign=”top”>45°</td>
<td id=”left7″ align=”left” valign=”top”>Light or Medium</td>
</tr>
<tr>
<td id=”left7″ align=”left” valign=”top”>Rear</td>
<td id=”left7″ align=”left” valign=”top”>30° (performance)
45° (recreation)</td>
<td id=”left7″ align=”left” valign=”top”>Medium or Heavy</td>
</tr>
<tr>
<td id=”title_left7″ rowspan=”2″>Downhill</td>
<td id=”left7″ align=”left” valign=”top”>Front</td>
<td id=”left7″ align=”left” valign=”top”>30°</td>
<td id=”left7″ align=”left” valign=”top”>Heavy or Extra-Heavy</td>
</tr>
<tr>
<td id=”left7″ align=”left” valign=”top”>Rear</td>
<td id=”left7″ align=”left” valign=”top”>30°</td>
<td id=”left7″ align=”left” valign=”top”>Heavy or Extra-Heavy</td>
</tr>
</tbody>
</table>

225+ lbs / 102+ kg

<table id=”weightChart”>
<tbody>
<tr>
<td class=”header” colspan=”4″>225+ lbs / 102+ kg</td>
</tr>
<tr class=”subheader”>
<td id=”title_left” align=”left” valign=”top”>Discipline</td>
<td id=”title_left” align=”left” valign=”top”>Truck</td>
<td id=”title_left” align=”left” valign=”top”>Geometry</td>
<td id=”title_left” align=”left” valign=”top”>Spring Strength</td>
</tr>
<tr>
<td id=”title_left” rowspan=”2″>Street / Freestyle</td>
<td id=”left” align=”left” valign=”top”>Front</td>
<td id=”left” align=”left” valign=”top”>30°</td>
<td id=”left” align=”left” valign=”top”>Extra-Heavy</td>
</tr>
<tr>
<td id=”left” align=”left” valign=”top”>Rear</td>
<td id=”left” align=”left” valign=”top”>30°</td>
<td id=”left” align=”left” valign=”top”>Extra-Heavy</td>
</tr>
<tr>
<td id=”title_left” rowspan=”2″>Park / Pool</td>
<td id=”left” align=”left” valign=”top”>Front</td>
<td id=”left” align=”left” valign=”top”>45°</td>
<td id=”left” align=”left” valign=”top”>Heavy or Extra-Heavy</td>
</tr>
<tr>
<td id=”left” align=”left” valign=”top”>Rear</td>
<td id=”left” align=”left” valign=”top”>30°</td>
<td id=”left” align=”left” valign=”top”>Extra-Heavy or Super-Heavy</td>
</tr>
<tr>
<td id=”title_left” rowspan=”2″>Ramp</td>
<td id=”left” align=”left” valign=”top”>Front</td>
<td id=”left” align=”left” valign=”top”>30° or 45°</td>
<td id=”left” align=”left” valign=”top”>Extra-Heavy</td>
</tr>
<tr>
<td id=”left” align=”left” valign=”top”>Rear</td>
<td id=”left” align=”left” valign=”top”>30°</td>
<td id=”left” align=”left” valign=”top”>Super-Heavy</td>
</tr>
<tr>
<td id=”title_left” rowspan=”2″>Longboard</td>
<td id=”left” align=”left” valign=”top”>Front</td>
<td id=”left” align=”left” valign=”top”>45°</td>
<td id=”left” align=”left” valign=”top”>Medium or Heavy</td>
</tr>
<tr>
<td id=”left” align=”left” valign=”top”>Rear</td>
<td id=”left” align=”left” valign=”top”>30° (performance)
45° (recreation)</td>
<td id=”left” align=”left” valign=”top”>Heavy or Extra-Heavy</td>
</tr>
<tr>
<td id=”title_left” rowspan=”2″>Slalom</td>
<td id=”left” align=”left” valign=”top”>Front</td>
<td id=”left” align=”left” valign=”top”>45°</td>
<td id=”left” align=”left” valign=”top”>Medium or Heavy</td>
</tr>
<tr>
<td id=”left” align=”left” valign=”top”>Rear</td>
<td id=”left” align=”left” valign=”top”>30° (performance)
45° (recreation)</td>
<td id=”left” align=”left” valign=”top”>Heavy or Extra-Heavy</td>
</tr>
<tr>
<td id=”title_left” rowspan=”2″>Downhill</td>
<td id=”left” align=”left” valign=”top”>Front</td>
<td id=”left” align=”left” valign=”top”>30°</td>
<td id=”left” align=”left” valign=”top”>Extra-Heavy or Super-Heavy</td>
</tr>
<tr>
<td id=”left” align=”left” valign=”top”>Rear</td>
<td id=”left” align=”left” valign=”top”>30°</td>
<td id=”left” align=”left” valign=”top”>Extra-Heavy or Super-Heavy</td>
</tr>
</tbody>
</table>

Bushing Design & Engineering

The Science Behind DEFCON Urethane

Modern urethane is composed of three basic ingredients:
• Small hard molecules (called chain extenders or cross linkers) that form a tough skeletal matrix.
• Larger elastic molecules (called polyols) that rely on the supportive structure of the chain extenders to function like muscle cells.
• A reactive glue (isocyanate) that holds everything together in three dimensions, like tendons connecting muscle to bone.

Defcon incorporates a revolutionary blend of advanced chain extenders that makes room for an extra helping of a top-grade polyol mix. Think of it as a sprinter with bones made of an advanced composite, like carbon nanotube. Since the “skeleton” is slimmer as well as stronger, more fast-twitch muscle can be packed around it, with no increase in overall volume.

G5 Truck Tuning & Troubleshooting

G5 Truck Mounting Advisory

Seismic G5 Baseplates have a unique structure and require full bottom surface support. Mount them directly onto the bottom of your deck, or else with stiff riser blocks between the trucks and the deck. Do not use rubber or urethane shock pads. These amplify stresses on the Baseplates – especially if the mounting bolts are over-tightened or tightened unevenly. Then relatively minor impacts can push the Baseplates past their breaking point.

G5 trucks will not fit through standard drop-through mounting holes, and they should not be drop-mounted to LDP bracket extensions. Unless extremely stiff riser blocks (preferably wood or even metal) are placed underneath the trucks, they should not be top-mounted on LDP brackets or on decks with drop-through mounting holes.

G5 Spring Truck Dis-Assembly and Re-Assembly

To dis-assemble a G5 truck: Place the board or truck upside-down, on the floor or a low workbench. Always pull off the Pivot Bolt Retaining Clip and untighten the Spring Tension Adjusters. Then press down on the hanger and hold while unscrewing the Pivot Bolt. (Note: If you don’t untighten the Spring Adjusters and hold the hanger down, Spring pressure adds resistance to unscrewing the Pivot Bolt and creates stresses that can damage the threads of the Baseplate Nut as the Bolt is removed.)

To re-assemble a G5 truck: Place the board or truck upside-down, on the floor or a low workbench. Always make sure to fully loosen the Spring Tension Adjusters. Otherwise much more pressure is needed to align the Hanger and Baseplate for insertion of the Pivot Bolt.

Set the Springs in the Baseplate with the sliding “piston” caps facing up. Place the Hanger on top, with the Spring Adjuster tips inside the piston cap sockets.

Press the Hanger down and hold it in place (using your bodyweight if necessary), to align the parts and keep Spring pressure off the Pivot Bolt. Then use a 7/32″ Allen wrench to press the Bolt through the truck and screw it into the Baseplate Nut. Fasten firmly, but don’t over-tighten. Sometimes a small downward push with the wrench helps the Bolt tip catch the threads of the Nut.

Always re-attach Pivot Bolt Retaining Clip after re-assembling truck. Replace Clip if it becomes bent.
Product modifications, including machining and use of non-Seismic components, are at your own risk.

If the Pivot Bolt unscrews only partway during disassembly and then gets stuck, the Baseplate Nut is probably stripped. To get the Pivot Bolt out of a stripped Nut, first place the truck in a vice (if possible). Pound the head of the Bolt back into the truck. This will force the stripped Nut out of its pocket in the Baseplate. Then slide a small flathead screwdriver (preferably #3) between the Nut and its pocket, or grasp the Nut with a strong pliers. This increases tension between the Pivot Bolt and the Nut, and it usually helps the Bolt cut through the Nut’s stripped threads. After unscrewing the Bolt, reassemble using a fresh Bolt and Nut.

G5 Spring Truck Noise

Seismic G5 Spring Trucks were engineered as a high-precision product, with virtually no slop in their steering articulation. So like a race car, they don’t dampen road vibrations much and may seem noisy compared to lower-precision trucks that use bushings. Some skaters are more sensitive to that than others.

Actual rattling noises can occur for a variety of reasons, regardless of the trucks you’re using. The most common cause is riding on rough surfaces with loose hardware and/or wheels that are too hard for the surface. In addition, bearing spacers can rattle between the bearings or against the axles if they’re the wrong size, or if the wheel core tolerances are off.

Try using softer wheels with properly-spaced bearings. Also check the fastening tension of your mounting hardware, wheel nuts, and truck pivot bolts. (Loose pivot bolts can also invite dirt and grime to gunk up the works, which in turn can lead to excess friction among the moving parts.)

The Seismic G5 technology itself was carefully engineered to eliminate squeaking, clicking and rattling, but a few seldom-seen issues can lead to these or other noises.

Most squeaking and clicking stems from friction between the small inner springs, the main outer springs, and the long-necked “sliding” spring caps. To reduce or eliminate the noise, try rotating the spring assemblies a quarter or half turn inside the spring chambers. (Loosen the tension screws first, then just turn the springs with your fingers.) After that, tighten the tension screws at least 1.5 turns. For added measure, drop a bit of silicone or graphite lubricant inside the long spring caps.

Finally, spring tension screws that are fully loosened may occasionally rattle inside the Seismic truck hangers, though ordinarily spring pressure keeps them quite still. Try tightening them 1.5 turns. This puts them in a “neutral” position where they function as intended. The trucks won’t feel stiffer when riding, but pressure from the springs will keep the screws from rattling.

Truck Wedging

The steering geometry of the Seismic G5 Spring Truck is absolutely fixed and perfectly consistent – either 30-degrees (Stable-Turn) or 45-degrees (Quick-Turn). The steering geometry of the Seismic Aeon Truck is also very consistent, especially for an RKP design. So wedged (angled) risers have a totally direct and predictable effect on their performance.

To quicken steering response, orient the wedge with the thin end facing the end of the deck. Usually called “wedging,” this is most commonly done with the front truck. Just remember this reduces your leverage on the G5 springs or Aeon bushings, so you might want to loosen them or even switch to softer ones.

To slow steering response, orient the wedge with the thick end facing the end of the deck. Usually called “de-wedging,” this is most commonly done with the rear truck, especially on racing boards. Just remember this increases your leverage on the G5 springs or Aeon bushings, so you might want to tighten them or even switch to stiffer ones.

Optimal truck mounting depends on many different variables – wheelbase, riding speed, skating style, personal preference and even body height. You’ll need to experiment to see what works best for you.

Geometry Selection

Seismic baseplates come in two geometries: Quick-Turn 45° and Stable-Turn 30°. For most boards, using a 30° truck at the tail and a 45° truck at the nose maximizes power, control, traction and stability. Exceptions: big vert, technical street and downhill boards (use 30° trucks on both ends) and low-speed recreational carvers (use 45° trucks on both ends)

Quick-Turn 45° baseplate & assembly

Stable-Turn 30° baseplate & assembly