If you own a Yamaha AG100, keeping the suspension in top shape is essential for off-road performance and safety. This article provides a detailed list of suspension components for the AG100, explaining each part's function and offering practical advice for maintenance and replacement. Whether you're rebuilding a worn-out bike or planning upgrades, this guide covers everything you need to know.
Front Suspension Components
The AG100 uses a telescopic fork system. Here are the key parts:
Inner and Outer Fork Tubes
- Inner tubes: Made of chrome-plated steel, they slide inside the outer tubes. Surface pitting or scoring can cause seal leaks. Replacement requires correct diameter (usually 33mm).
- Outer tubes: Housing the springs and damping cartridges. Cracks or bends require immediate replacement.
Fork Seals and Dust Wipers
- Seals: Prevent oil leakage and keep dirt out. Standard size for AG100 is 33x45x10.5mm. Replace in pairs when leaking.
- Dust wipers: Sit above the seals to wipe dirt off inner tubes. Replace with seals.
Fork Springs
- Linear rate springs provide a balance of comfort and control. Aftermarket options (e.g., progressive springs) can improve handling for heavier riders or aggressive terrain.
Damping Components
- Damper rod or cartridge: Controls compression and rebound damping. AG100 typically uses a damper rod design. Worn rod or worn internal o-rings lead to poor damping. Rebuild kits with new o-rings and spacers are available.
- Fork oil: Viscosity (recommended 10W) affects damping. Change oil every 30 hours or when seals are replaced.
Other Parts
- Fork caps: Threaded caps that preload the springs. Reuse unless damaged.
- Cushion springs: Small springs inside the fork that prevent metal-to-metal contact on full compression. Check for breakage.
Rear Suspension Components
The AG100 rear suspension uses a swingarm with a single shock (monoshock).
Rear Shock Absorber
- Coil-over shock: Contains spring and damping unit. Stock shock is non-adjustable. Upgrades (e.g., from YSS or Ohlins) offer preload and rebound adjustment.
- Spring: Common spring rate around 450 lb/in. Sag should be set to 30% of travel.
- Seals and bushings: Internal seals wear, causing damping loss. Rebuild kits are not common; replacement shock is often more cost-effective.
Swingarm and Linkage
- Swingarm: Pivot arm holding the rear wheel. Check for twist or cracks. Swingarm bearings (needle bearings) require periodic greasing.
- Linkage (if equipped): Some AG100 models have a simple linkage connecting shock to swingarm. Bushings and seals here wear out.
- Rear shock mounting hardware: Bolts, spacers, and nuts must be torqued to spec (typically 35-45 ft-lb). Use thread locker.
Rear Suspension Bushings
- Swingarm pivot bushings: Two sets (left and right). Replace if play develops.
- Shock rod end bushings: Rubber or polyurethane. Polyurethane lasts longer and improves response.
Steering and Related Parts
Steering Stem Bearings
- Tapered roller bearings (upper and lower). Worn bearings cause wobble. Replace with quality kits (e.g., All Balls).
- Steering stem nut: Castle nut; torque to 65 ft-lb, then align with cotter pin hole.
Handlebar Mounts
- Rubbers and clamps that isolate vibration. Replace if cracked.
Maintenance and Replacement Tips
- Inspect regularly: Look for fork oil leaks, shock damage, and loose bolts.
- Bleed fork air: After off-road use, open bleeder screws to release built-up pressure.
- Set sag: On rear shock, adjust preload so sag is around 30mm (with rider).
- Lubrication: Grease swingarm and steering stem bearings annually.
- Torque specs: Use a manual; overtightening can crack tubes.
Aftermarket Upgrade Options
Several brands offer AG100 suspension upgrades:
- Fork cartridges: Emulators or damper rod modifications for better performance.
- Progressive springs: Available from Hagon, Race Tech, or YSS.
- Custom shock: Brands like YSS, DNM, or Ikon produce bolt-on rear shocks with adjustments.
- Swingarm braces: Reduce flex for hard riding.
Note: Ensure that any aftermarket part is specifically designed for the AG100; some parts from XT225 or TW200 may fit but require verification.
Practical Final Recommendation
For most AG100 owners, a solid starting point is to replace worn fork seals and change fork oil, then set correct sag on the rear shock. If the stock rear shock is leaking or has lost damping, consider a quality replacement like the YSS MZ366 (preload adjustable). For aggressive trail riding, upgrade fork springs (0.45 kg/mm) and use 10W oil. Keep your swingarm bearings greased and steering head bearings tightened to prevent wobble. A well-maintained AG100 suspension transforms the bike's handling and extends its life.
This list covers all essential AG100 suspension parts. Use it as a checklist when servicing your motorcycle. Regular attention to these components ensures safe, predictable handling on every ride.