Seismic® Defcon Barrel Bushings
Deeper Lean with Truer, More Fluid Steering • Finer Control and Highly-Energetic Response • Precision Fit
Available in eight (8) color-coded durometers and three (3) precision-fit heights.
Price is for a single pair of two (2) barrel bushings. Discounted pricing for Bundles of five (5) pairs in 81A through 93A (all in a single height).

Seismic’s Defcon ultra-high-rebound urethane has a remarkable set of unique and highly-advanced properties – and now we’ve applied it to bushings! Defcon is the fastest wheel formula in the history of skateboard racing – credited with virtually every significant world distance and speed record, including the official Guinness Standup mark. (Pete Connolly, 91.17 mph / 146.73 kph – Sept. 16, 2017, at The Top Speed Challenge in Quebec, Canada.)

A major step forward in bushing performance…
• Deeper lean and truer, more fluid steering with less lateral hanger slop!
• Smoother, more linear resistance profile – Consistent feel • Advanced control
• Very calm and predictable at speed compared to other bushing formulas – Not bouncy, nervous, or twitchy
• Highly-energetic yet smooth and controlled return-to-center
• Larger compression range compared to other bushing formulas in the same duro – No premature packing • Fuller wheel contact (less “outside wheel lift”) at maximum lean angles

Fine-tuned dimensions for high-performance fit!
• Full 1.0-inch outer diameter optimizes seating in bushing pockets of finer modern hangers.
• Inner diameter carefully calibrated for snug fit on standard kingpin shafts.
• Mold-top ends precisely machined for exact height and superior flatness. – No warped end surfaces.
• Minimal radius on mold-bottom edges, and zero radius on mold-top edges. – Fuller contact with bushing seats and washers.

Three (3) precision-fit heights…
• Standard 0.60-inch (15mm): Optimal height both Board-Side (BS) and Road-Side (RS) for many modern longboard trucks, especially those assembled with BS washers. (e.g., Bear, Caliber, Paris, Dont Trip Poppy / Slalocybin, 161)
• Medium 0.65-inch (16.5mm): Optimal height both BS and RS for brands including Aera, Carver, and Sabre. Also fits well both BS and RS in many modern trucks where BS washers are optional or omitted. (e.g., Dont Trip Poppy / Slalocybin) If paired with a shorter bushing, fits well in many trucks assembled with BS washers. (e.g., Bear, Caliber, Paris) Fits same trucks both BS and RS if BS washer is removed.
• Tall 0.75-inch (19mm): Optimized fit both BS and RS in many modern race trucks. (e.g., Exile, Rogue, Ronin, Skoa, Valkyrie, Zealous, Dont Trip Boomer / DH-Cybin / Haki / Molly) Also fits BS in Caliber trucks if shim is removed.

Finer points on bushing fit
• Every truck design has unique bushing fit patterns. From one brand to another, and even among different models from a single brand, the variations are dizzying in number and daunting to track.
• Many trucks assembled with BS washers (e.g., Bear, Caliber, Paris) perform well with one Medium bushing (either BS or RS), as long as it’s paired with a second bushing that’s shorter. Some truck models (e.g., Bennett, Dont Trip Bhanger / Delirium) are designed to take Tall BS bushings and shorter RS bushings. Still other truck models can accommodate either Standard or Medium bushings both BS and RS.
• Optimal bushing height depends partly on whether the truck assembly includes a BS washer, which takes up 1.5mm – 2.0mm of the linear space available for bushings on the kingpin shaft. (The RS washer, normally placed between the kingpin nut and the RS bushing, takes up an equal amount of linear space.)
• Trucks whose baseplates have a narrow bushing platform usually perform best with BS washers, which improve bushing support at the BS interface. Trucks whose baseplates have a wider bushing platform often perform equally well (or better) without BS washers.
• Kingpin length also plays a role. Trucks with longer kingpins can accommodate a wider range of bushing heights; trucks with shorter kingpins are only compatible with a narrow band of bushing heights. For this reason, older Paris-brand trucks (with longer kingpins) accommodate taller bushings than newer Paris-brand trucks (with shorter kingpins).

Bushing fit hacks
• If your bushings seem too tall for your trucks, try sanding on grip-tape to reduce their height.
• Certain older truck designs (e.g., GOG, Randal, Bear prior to Gen 6) have hanger bushing pockets that are tight on Defcon bushings’ true 1.0-inch outer diameter. To ease fit in these cases, try sanding bushing edges on grip-tape to add radius.

Note: Defcon bushings may feel slightly softer than comparable duros from other brands using more basic urethane formulas. For optimal bushing performance, do not under-tighten or over-tighten kingpin nuts. Replace bushings that show signs of excessive wear, weathering, or aging.

Pivot Bolt Kit for Seismic G5 Spring Truck.

Unfortunately our previous truck manufacturing partner imploded during the pandemic, due to issues related to the global crisis. We’ve re-grouped with a new factory and hope to have fresh stock of our spring trucks sometime late this year or early next. But please note that it’s a significant challenge to re-boot production of this extremely technical product, which is assembled using an unusual variety of custom components that must be sourced from multiple specialized vendors. Thank you for your patience and understanding.

Comes with Baseplate Nut and Fastening Clip.

Price is for ONE (1) Pivot Bolt Kit.

Note: Will not fit Seismic spring trucks from versions prior to the G5. Click here to purchase Pivot Bolt Kit for older Seismic Spring Truck models.

Baseplate Kit for Seismic G5 Spring Truck.

Unfortunately our previous truck manufacturing partner imploded during the pandemic, due to issues related to the global crisis. We’ve re-grouped with a new factory and hope to have fresh stock of our spring trucks sometime late this year or early next. But please note that it’s a significant challenge to re-boot production of this extremely technical product, which is assembled using an unusual variety of custom components that must be sourced from multiple specialized vendors. Thank you for your patience and understanding.

Available in Stable-Turn 30-degree Geometry and Quick-Turn 45-degree Geometry.

Comes with Pivot Bolt, Pivot Nut, and Fastening Clip.

Price is for ONE (1) Baseplate Kit.

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.