Slappy ST1 Inverted Hollow Ultra Low 8.5″ Polished Truck

Slappy Trucks is Mike Sinclair’s skateboard truck label — an industry vet with decades at Thunder and Venture who set out on his own in 2023. The line-up: the ST1 chassis in Classic, Inverted, Hollow, Lights and Curb Killer, plus a pro model from Olympic gold medalist Arisa Trew and Wide Boy axles for cruiser setups. If you want a truck that handles slappies, ledges and flatground pop without compromise, this is where you land.

Heritage — Mike Sinclair’s solo project

Mike Sinclair spent decades running the Thunder team and knows the truck market from the inside as well as anyone. He launched Slappy in 2023 with a clear focus: axles that honestly cover the full spectrum — from pop tricks to ungrouted curb grinds. No marketing fluff, no "pro-light" nonsense, just considered geometry and a team that tests the product daily. The name says it all: slappies — the no-pop curb grind — are one of skating’s oldest disciplines and a litmus test for truck design at the same time.

Which Slappy trucks for which skater?

The ST1 chassis is the base; variants differ in kingpin position, weight and axle material.

• ST1 Classic — standard kingpin, solid axle, polished. The all-rounder: stable on manuals, honest on grinds, in widths from 7.50" to 10.00". First pick if you don’t want to overthink it.
• ST1 Inverted — flipped kingpin gives extra clearance for crooks and feebles without the kingpin scraping coping. Subtle geometry shift, big difference in grind feel.
• ST1 Hollow — hollow kingpin and hollow axle, noticeably lighter without sacrificing stiffness. Also available as Hollow Low for smaller decks and quicker flips.
• ST1 Inverted Hollow — both worlds combined for the maxed-out setup. In gunmetal and polished.
• ST1 Lights — anodized hangers in red, blue and gold. Looks with function, same ST1 geometry.
• ST1 Curb Killer — hanger shape sharpened specifically for slappy curbs, slides over concrete noticeably better. If your day is a single curb, this is your truck.
• ST1 Arisa Trew Pro — pro model from the first Olympic gold medalist in street skateboarding (Paris 2024). In 8.00" and 8.25".
• Wide Boy 11.00" — XXL truck for cruisers, old-school shapes and anything over 10" deck width.

Build & material

Hangers are cast aluminum, axles are chromoly. Rule of thumb for width: hanger width should roughly match deck width — 8.0" deck runs clean on 8.0" ST1, 8.5" deck on 8.5" ST1. The polished line keeps bare aluminum, the Lights series is anodized. Bushings ship in a medium durometer — if you want softer or firmer turn, swap them out for Bones bushings.

Setup tips

Slappy ST1 plays well with pretty much any deck and wheel setup. For all-round and ledges, run Spitfire or Bones wheels in 52–54 mm. More park and transition? Move up to 55–58 mm. Browse decks in our selection; complete boards with Slappy trucks configurable on request.

FAQ

What sets Slappy apart from Thunder or Venture?
Mike Sinclair learned the game at Thunder — Slappy is his own swing at it, focused on slappy-friendly hanger geometry and a range that runs from 7.5" pop setups up to 11" Wide Boy. If Thunder sits too tall for you or Venture too narrow, ST1 is the sweet spot.

Which width do I need?
Rule of thumb: hanger width ≈ deck width, in 0.25" steps. 8.0" deck = 8.0" ST1. Slightly narrower turns quicker, slightly wider stands more stable.

Is the hollow version actually noticeably lighter?
Yes — the difference between ST1 Classic and ST1 Hollow runs around 60–90 g per pair. You feel it on fast flatground tricks. For park and bowl, Classic is usually plenty.

Curb Killer or Inverted — which is better for slappies?
Curb Killer is explicitly designed for slappies; Inverted gives more grind clearance overall. If you live on curbs, go Curb Killer.