Maxima Racing Fork Fluid 85/150 5wt - 1L - 59901-5

The Maxima Racing Fork Fluid 85/150 5wt (Part # 59901-5) is a professional-grade, mineral-based fork oil engineered specifically for high-performance front suspension systems. Designed to work with both standard and cartridge-type forks found on modern off-road and on-road motorcycles, ATVs, and UTVs, this 1-liter bottle delivers the consistent damping performance that serious riders and racers demand. Whether you're rebuilding your forks after a hard season or dialing in suspension feel for the track, Maxima's Racing Fork Fluid is a go-to choice in the powersports community.

Key Features & Benefits

• Mineral-Based Formula for Broad Compatibility: Formulated from a mineral oil base, this fork fluid is compatible with a wide range of fork seal materials and elastomers, making it a versatile choice for most modern suspension applications.
• Shear-Stable, High Viscosity Index: The shear-stable formulation resists viscosity breakdown under repeated compression and rebound cycles, so your 5wt fluid stays at the intended weight throughout the ride — not thinner from heat and mechanical shear.
• Maintains Film Strength to Reduce Wear: Industry-leading anti-wear chemistry keeps a protective film between metal surfaces inside the fork internals, helping extend the service life of tubes, bushings, and valving components.
• Reduces Stiction and Running Friction: The advanced proprietary additive system is specifically engineered to prevent stiction — the sluggish, sticky fork action that robs you of small-bump sensitivity — while simultaneously reducing overall running friction for a smoother, more responsive feel.
• Minimizes Foaming and Air Entrainment: Foam and entrained air in fork fluid can cause inconsistent, spongy damping. Maxima's anti-foaming chemistry keeps the fluid aerated-free so damping performance remains predictable lap after lap.
• Eliminates Corrosion and Conditions Seals: The ultra-clean formulation actively fights internal corrosion while conditioning fork seals to maintain their elasticity and prevent premature leaks — a real advantage in wet or muddy riding conditions.
• 5wt / 85/150 Grade: The 5-weight viscosity is one of the lighter options in Maxima's fork fluid lineup, favored for applications requiring quick, responsive rebound and a plush small-bump feel. The 85/150 viscosity grade classification helps riders cross-reference compatibility with OEM specifications.

Specifications

• Brand: Maxima Racing Oils
• Part Number: 59901-5
• Viscosity: 5wt (85/150 grade)
• Volume: 1 Liter (33.8 oz)
• Base Oil Type: Mineral-based
• System Compatibility: Standard-type forks and high-performance cartridge forks
• Country of Origin: United States

Fitment & Application

Maxima Racing Fork Fluid 5wt is designed as a universal front suspension fluid suitable for all modern off-road and on-road upside-down (USD) forks, as well as most late-model applications with conventional standard-type fork assemblies. This covers a broad spectrum of powersports vehicles including:

• Motocross and enduro dirt bikes (MX/off-road)
• Street and sport motorcycles with standard or inverted fork setups
• ATVs and UTVs with front fork suspension
• Dual-sport and adventure bikes

Because fork fluid requirements vary by manufacturer and model — and because OEM-specified viscosity grades differ across platforms — always verify your owner's manual or service manual for the correct recommended weight before filling. The 5wt is generally suited for applications where a lighter, more responsive fork action is desired or where the OEM specifies a 5-weight equivalent.

What's in the Box

• 1 x Maxima Racing Fork Fluid 85/150 5wt — 1 Liter bottle (Part # 59901-5)

Why Buy from ThreePiece.us

• Free Shipping on Every Order: No minimum required — your Maxima fork fluid ships free to your door anywhere in the continental US.
• Affirm Financing Available: Split your purchase into manageable payments with Affirm — a helpful option when stocking up on fluids alongside a larger suspension service or rebuild.
• Expert Fitment & Parts Support: ThreePiece.us has served over 10,000 customers with personalized fitment guidance. Not sure which viscosity weight is right for your bike or build? Reach out to the team directly — they're here to help you get the right fluid the first time.
• Genuine Products: ThreePiece.us carries 100% authentic products — never counterfeit or gray-market inventory.
• Price Match Guarantee: Found it lower somewhere else? ThreePiece.us offers a price match guarantee so you can buy with confidence.

Frequently Asked Questions

Q: What types of forks is this fluid compatible with?
A: Maxima Racing Fork Fluid 5wt is designed for use in both standard-type and high-performance cartridge fork systems. Maxima specifically notes compatibility with all modern off-road and on-road upside-down forks, as well as most late-model standard fork applications.

Q: What does the "85/150" designation mean on the label?
A: The 85/150 is a viscosity grade classification used to describe the fluid's viscometric properties. It's a common cross-reference standard used in the suspension fluid industry, and it can help you match this fluid against OEM-specified fluid grades when consulting your bike's service manual.

Q: Is the 5wt the only viscosity available, or are there other options?
A: Maxima offers their Racing Fork Fluid in multiple viscosity weights — including 7wt, 10wt, and 15wt in addition to the 5wt offered here. Each weight is suited to different fork setups and rider preferences. If you're unsure which weight is correct for your application, consult your OEM service manual or contact ThreePiece.us for guidance.

Q: How much fluid does this bottle contain — is one liter enough for a full fork service?
A: This bottle contains 1 liter (33.8 oz) of fork fluid. Fork fluid capacity varies by motorcycle model, fork diameter, and oil level specification, so we recommend consulting your service manual for the exact capacity of each fork leg. For many dirt bikes and sport bikes, one liter is sufficient for a complete service of both fork legs, but some larger-diameter or longer-travel forks may require additional fluid.