BOS suspension systems are engineered for high-performance cycling and motorsports, delivering precision damping and durability. However, like any precision component, they require periodic maintenance and occasional replacement of worn parts. Knowing which BOS suspension spare parts you need and how to source them correctly keeps your fork or shock performing at its peak. This guide covers the essential spare parts, compatibility considerations, and practical advice for US riders and mechanics.
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BOS-SR15N-JN Fits for Bosch Starter
Understanding BOS Suspension Systems
BOS is a French brand renowned for its mountain bike forks and rear shocks, as well as suspension components for motorcycles and snowmobiles. The most common applications in the US market are high-end mountain bike forks like the BOS Deville, Stoy, and Kirk, along with rear shocks such as the BOS Void. These systems use advanced damper technologies and air or coil spring designs. Spare parts for BOS suspension are not as widely available as those for mainstream brands, so proper identification and sourcing are critical.
Common BOS Suspension Spare Parts
Over time, seals wear, bushings develop play, and internal fluids degrade. The following are the most frequently needed replacement parts for BOS suspension.
Seals and Wipers
The upper and lower seals prevent dirt and moisture from entering the fork or shock stanchions. BOS uses proprietary seal designs. Common replacement seals include dust wipers, oil seals, and air seals. For forks, you may need a seal kit specific to the model (e.g., Deville or Stoy). For rear shocks, seal heads often include both an inner and outer seal. Always use genuine BOS seals or verified equivalents to avoid leakage and performance loss.
Bushings and Bearings
Slider bushings inside the fork lower legs wear over time, resulting in play or stiction. BOS forks typically use IGUS bushings or similar low-friction materials. Rear shocks may have DU bushings or spherical bearings at the mounting points. Replace bushings when there is noticeable play or roughness. Bearing and bushing kits are available for specific models.
Air Spring and Coil Spring Components
BOS air springs include air pistons, O-rings, and seal heads. If your fork feels too soft or loses air pressure, the air spring seals might be leaking. For coil shocks, replacement coil springs are available in various rates. Ensure you select the correct spring length and rate for your BOS shock model.
Damper Cartridges and Valves
Damper cartridges contain the intricate shim stacks and piston assemblies that control compression and rebound. While entire damper cartridges are available as spare parts for some BOS models, more common replacements include shim stacks, valve parts, and bladder seals. If the damping feels inconsistent or there are oil leaks from the damper, the cartridge may need rebuilding or replacement.
Where to Purchase Genuine BOS Spare Parts
Because BOS has a relatively small dealer network in the US, sourcing genuine parts requires diligence. Avoid generic seals or unbranded parts that may not fit or perform properly. The safest sources are:
- Authorized BOS service centers (listed on the official BOS website)
- Reputable online suspension specialists that stock BOS parts
- Direct from BOS if you have a dealer account
Be wary of listings that do not specify model numbers or part numbers. Cross-reference with BOS service manuals to confirm fitment.
How to Ensure Compatibility
BOS suspension components are model-specific. A seal for a 2018 BOS Deville will not fit a 2021 model if the stanchion diameter changed. To find the correct spare parts:
- Locate the model name and serial number on your fork or shock.
- Check the BOS website for technical documents or parts diagrams.
- Note the travel, spring type (air or coil), and year of manufacture.
- When ordering, provide the exact model and part number from the manual.
If you are unsure, contact a BOS-authorized mechanic with your suspension details. For example, BOS forks often use a 35mm or 36mm stanchion; confirm before buying seals.
DIY vs. Professional Service
Replacing seals and bushings on BOS suspension is more involved than on some other brands due to proprietary tools and internal designs. Basic tasks like changing foam rings or replacing air spring seals can be done at home with a clean workspace, correct oil, and basic tools. However, damper cartridge rebuilding or fork full service typically requires special tools (e.g., bleed blocks, snap ring pliers) and experience with pressurized systems.
If you lack the tools or confidence, send your suspension to a qualified BOS service center. Improper assembly can lead to oil leaks, poor performance, or damage. Many US shops that specialize in high-end suspension can service BOS components.
Recommended Maintenance Schedule for BOS Suspension
- After every ride (in wet/muddy conditions): Wipe stanchions, clean foam rings, and check for air seal leaks.
- Every 30–50 hours of riding: Change foam rings, clean and re-oil seals, and replace air spring seals if needed.
- Every 100–150 hours or annually (whichever comes first): Full fork/shock lower leg service (seals, bushings, oil). Damper rebuild every 200 hours.
- After major pressure loss or abnormal behavior: Inspect immediately and replace worn parts.
Using genuine BOS suspension spare parts extends the life of your components and maintains the ride quality you expect from the brand.
Final Recommendation
For US riders, the best approach to maintaining BOS suspension is to prioritize genuine spare parts and follow the manufacturer’s service intervals. Start with seal kits and air spring seals, which are the most common wear items. If you ride aggressively or in dirty conditions, upgrade to ski-style wipers if available for your model. When in doubt, consult an authorized BOS service center. Investing in the correct BOS suspension spare parts ensures your fork or shock continues to deliver the performance that makes BOS a top-tier choice.