# Seismic -75mm Urchin 78a, 80a(Stoneground surface)

[Chase Hiller The Big Urchin](https://vimeo.com/278542702) from [Seismic Skate Systems](https://vimeo.com/seismicskate) on [Vimeo](https://vimeo.com).

**Specs:**  
Height: 75mm  
Durometers: 78a, 80a  
Formula: Defcon(78a), Elixir(80a)  
Contact Patch: 48mm  
Hub Setting: Off Set  
Edges: Radiused outside edge  

Sold in sets of FOUR wheels.  

Ideal for fast freeride, the 75mm by 48mm Urchins love goin’ FAST, gettin’ sideways, and rippin’ corners!  
• height and width perfectly balanced for modern all-around riding  
• slide release that’s smooth, easy, comfortable, and predictable  
• amazing in-slide feedback and control, bleeding just the right amount of speed  
• secure, comfy hookup  
• vibrant ‘thane lanes  
• consistent wear

_**Available in TWO proprietary formulas, with finely-tuned durometer choices.**  
_**Defcon**™: **Guinness WR speed** – g_et up to speed faster!_ • easy, predictable in-slide feedback • extremely slow, consistent wear  
_• 78A Mango (stoneground): _super fast roll; exceptionally easy release; ultra-smooth sliding; minimal grip__  
**Elixir™**: smooth, predictable slides (even on concrete) • easy release and hookup • supreme control • bright ’thane lines_  
• 80A Red (stoneground): _Floaty, velvet-smooth slides with bright ’thane lines__

Molded around our advanced Mini-EC hub – preserves ample tire thickness while saving over ½-ounce per wheel, stiffening the inside edge, and super-charging inside edge rebound.  Translation: Better roll speed, more predictable handling, and better slide control!

## Details

- **Price:** 628.0 HKD - 738.0 HKD
- **Vendor:** Seismic
- **Type:** Wheels
- **Tags:** 75mm, 78a, 80a, Freeride wheels, Round&Beveled, Seismic, Stone-grounded, Wheels

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Mango (78a, Defcon) | 738.00 HKD | In stock |
| Red (80a, Elixir) | 628.00 HKD | In stock |

## Images

- Seismic -75mm Urchin 78a, 80a(Stoneground surface)
- Seismic -75mm Urchin 78a, 80a(Stoneground surface)

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> Source: [SBDW Longboards Hong Kong](https://sbdwlongboards.com/products/seismic-75mm-urchin-elixir-formula)
> Updated: 2026-04-20