AMSOIL Shock Therapy Suspension FluidA professional-grade synthetic fork or shock oil that is ideal for motocross, street bike, snowmobile, ATV or off-road applications. Delivers outstanding performance on the track, trail or street. Shock Therapy is a dramatic upgrade over stock suspension fluids. Available in #5 weight (Light) or #10 weight (Medium).

Shock Therapy packages sizes include:
Single Quart (946 ml) Bottles (or buy case of 12)
5 US Gallon (18.9 L) Pail
55 US Gallon (208 L) Drum

Oildepot can sell Shock Therapy Synthetic Suspension Fluid at wholesale prices in Canada and the United States. Contact us for a price list using the form on this page.  

AMSOIL Shock Therapy Synthetic Suspension Fluid is suitable for any motorcycle fork or rebuildable shocks from all OEM manufacturers. Notable suspension brands include:

  • Kayaba
  • Showa
  • Ohlins
  • Harley-Davidson
  • FOX
  • RydeFX
  • Marzocchi
  • Bilstein
  • Penske
  • WP
  • Racetech
  • Koni
  • And Many More…







Features and Benefits of AMSOIL Shock Therapy Synthetic Suspension Fluid

  • Suitable for forks or shocks
  • Resists heat and fluid fade
  • Lowers friction
  • Consistent operation in extreme hot or cold temperatures
  • Conditions seals for long life
  • Combats shearing for stable viscosity
  • Prevents foaming
  • Controls internal wear in shocks and forks
  • Formulated for long service life

Why Use Synthetic Fork and Shock Oil?

Synthetic oil has two traits that make it especially suitable for use in suspension components. For obvious reasons, the lower friction brought by synthetics allows for smoother operation and improved wear protection. The low friction environment also allows for cooler operation and prevention of heat build-up. As heat is kept under control, reliable, fade-free suspension function can be expected from start to finish during long races and during the toughest days on the trail.

Another strength offered by synthetic oil is shear stability. This means that the oil’s viscosity is not “sheared down” or thinned out due to extreme heat or vigorous mechanical activity. Therefore the viscosity of the oil stays consistent over long service intervals and that suspension performance is stable and predictable.

AMSOIL didn’t just create a synthetic suspension fluid in order to fill a spot on the market. They performed vast amounts of research and development with their best synthetic chemistry to create what they felt was the best fork and shock oil on the planet.

Performs in Extreme Cold or Heat

As mentioned, AMSOIL Shock Therapy Synthetic Suspension Fluid delivers cooler operation in extreme heat and under serious work loads. Another outstanding feature of this synthetic fork and shock oil is that it performs equally well in extreme cold. With cold-pour-points of -53°C (#5 Light) and -48°C (Medium), suspension performance will not be compromised by very cold weather conditions. This makes Shock Therapy an obvious choice for snowmobile and other winter applications.

Preserves Fork and Shock Seals

The synthetic make up of Shock Therapy Suspension Fluid has the inherent ability to keep fork and shock seals malleable and conditioned. Drying and cracking is prevented, so oil leaks are kept at bay.

Serious Foaming Prevention

As you can well imagine, suspension fluid leads a very violent existence. With lesser suspension fluids, the constant mashing can create oil “foaming”. This is where tiny air bubbles can form in the oil. The problem with foaming is that once these air bubbles are forced into tight tolerances, they will burst and the area is left without lubrication for a brief moment. This can cause accelerated wear and poor dampening performance. AMSOIL Shock Therapy Synthetic Suspension Fluid was developed with an aggressive anti-foaming additive package to keep this problem completely under wraps.

Mixing Light and Medium Suspension Oil

AMSOIL Shock Therapy Light #5 and Medium #10 can be mixed in equal portions to create an approximate 7.5 weight oil.

Service Life of AMSOIL Shock Therapy Synthetic Suspension Fluid

AMSOIL Shock Therapy Synthetic Suspension Fluid should be changed at intervals as prescribed by the fork or shock manufacturer.

AMSOIL Light #5 Weight Replaces The Following Products

  • Bel-Ray Fork 5W
  • Bel-Ray Racing Suspension Fluid 3W
  • Bel-Ray Racing Suspension Fluid 5W
  • Bilstein Bilmst 3030 KYB
  • Fuchs-Silkolene Pro RSF
  • Golden Spectro Very Light
  • Golden Spectro Cartridge Fork Fluid 5W
  • Klotz 5W
  • KYB K2C
  • Maxima 75-390 Racing Shock Fluid Light 3W
  • Maxima 75-390 Racing Shock Fluid Light 3W
  • Maxima 85-150 Racing Shock Fluid Light 5W
  • Ohlins Front Fork #5
  • PJ1 Fork Oil
  • Pro Circuit PC-01 Fork Fluid
  • Pro Circuit PC-02 Racing Shock Fluid
  • Pro Honda High Performance SS-25 Shock Fluid
  • Race Tech Light
  • Race Tech US-1 Ultra-Slick Shock Fluid 2.5-5W
  • Race Tech USF-05 Ultra-Slick Fork Fluid 5W
  • Red Line Light
  • Ryde FX Slide Shock Oil
  • RI Suspension Fluid
  • Showa SS05













AMSOIL Medium #10 Weight Replaces The Following Products

  • Bel-Ray HVI 10W
  • Bel-Ray Fork 10W
  • Fox Racing Oil
  • Fuchs Silkolene (AMSOIL #10 Will Offer Slower Rebound)
  • Harley Davidson Screaming eagle Fork Oil Heavy (AMSOIL #10 Will Rebound Faster)
  • Harley Davidson Fork Oil Type B
  • Harley Davidson Fork Oil Type E
  • Klotz 10W
  • Spectro SK400 Shock & Fork Oil
  • Maxima Fork Oil 10
  • Maxima 11-390 Racing Shock Fluid Medium 7W
  • Ohlins Front Fork Fluid #15
  • Pro Honda SS-8 Suspension Fluid #10
  • Redline Medium
  • Spectro Fork Oil 10W
  • Spectro SK400 Shock & Fork Oil










AMSOIL Shock Therapy Synthetic Suspension Fluid Is Suggested For The Following Specifications:

  • Denison HF-0, HF-1, HF-2
  • Lee Norse 100-1
  • Ford M6C-32
  • BF Goodrich 0152 (except PM 500 Series)
  • Racine Variable Vane Pump
  • DIN 51524 Part 2
  • Afnor E 48-603



STL #5

STM # 10

Kinematic Viscosity @ 100°C, cSt (ASTM D-445)



Kinematic Viscosity @ 40°C, cSt (ASTM D-445)



Viscosity Index (ASTM D-2270)



Pour Point, °C (ASTM D-92)



Flash Point, °C [°F]

174° [345°]

192° [377°]

Fire Point, °C [°F]

192° [378°]

208° [406°]

Four Ball Wear Test (ASTM D-4172: 40kg, 75°C, 1200 rpm, 1 hr) Scar Diameter, mm



Foam, ml (ASTM D-892) Sequence I, II, III

65/0, 60/0, 65/0

65/0, 60/0, 65/0

Blender Test (25°C, low speed, 1 min.)

2.5 mins to settle, 8% foam

2.5 mins to settle, 8% foam