HP Velotechnik is renowned for building high-quality recumbent trikes and bikes with sophisticated suspension systems. Whether you own a Scorpion, Gekko, or Grasshopper fx, understanding the available suspension parts is key to maintaining comfort and performance. This guide covers the components, their functions, and how to choose the right parts for your ride.
Overview of HP Velotechnik Suspension Systems
HP Velotechnik uses a combination of elastomers, springs, and dampers to smooth out bumps. Their suspension designs vary by model: the Scorpion series features full independent rear suspension (IRS), while the Gekko uses a simpler but effective rear swing arm. Front suspension usually comes as an option, often with a leading-link fork or a telescopic fork. Understanding these differences helps you identify which parts fit your trike.
Front Suspension Components
Leading-Link Forks
Many HP Velotechnik trikes offer a leading-link front suspension fork. This design uses a linkage system that isolates braking forces from the suspension motion. Key parts include:
- Fork crown and steerer tube: Made from aluminum or steel, depending on the model.
- Linkage arms and pivot bearings: These allow the wheel to move vertically while maintaining geometry.
- Elastomer or spring unit: The damping element; often replaceable.
- Brake mount: For disc brakes, usually a post-mount or IS standard.
Telescopic Forks
Some models use a telescopic fork similar to mountain bikes. Components to know:
- Stanchions and lowers: Hard-chrome coated for durability.
- Air spring or coil spring internals: For adjustability.
- Damper cartridges: Oil-filled for rebound and compression control.
- Seals and wipers: Keep dirt out; replace regularly.
Compatibility Notes
Not all forks fit all trikes. Check the steerer tube diameter (usually 1-1/8 inch) and axle-to-crown length. HP Velotechnik offers specific part numbers; order from a dealer to ensure fit.
Rear Suspension Components
Swing Arm and Pivots
The rear swing arm connects the wheel to the frame. Pivot bearings wear over time. Look for:
- Needle bearing sets: Some models use sealed cartridge bearings for less maintenance.
- Pivot bolts and spacers: Often Ti or stainless steel for weight savings.
Shock Absorbers
HP Velotechnik uses both coil-over shocks and air shocks. Common parts:
- Spring rate options: Choose based on rider weight and load.
- Damper adjustments: Rebound and compression clickers.
- Eyelet bushings: Replace when squeaking or loose.
Independent Rear Suspension (IRS) on Scorpions
Scorpion trikes have a complex IRS with multiple linkage points. Key parts:
- Upper and lower control arms: With spherical bearings.
- Toe links: Keep wheel alignment; adjustable.
- Anti-roll bar: Optional for stability.
Elastomers and Springs
Elastomers are used in both front and rear suspension on entry-level models like the Gekko. They come in different densities (soft, medium, firm). Over time they compress and lose performance. Replace them as a set.
Springs are either steel or titanium. Steel springs are affordable but heavier. Titanium springs save weight. Measure the free length and inner diameter to match your shock.
Maintenance Tips
- Clean pivots after every ride if you ride in wet or dusty conditions. Use a gentle degreaser and relube with PTFE grease.
- Check for play: Grab the wheel and try to move it laterally. Any clunk indicates worn bearings.
- Inspect elastomers: If they show cracks or are mushy, replace them.
- Service shocks annually: Rebuild air shocks with new seals. Coil shocks need oil changes.
- Torque specs matter: Over-tightening damages bearings. Use a torque wrench.
Upgrading Your Suspension
When to Upgrade
- You want more adjustability (e.g., from elastomer to air shock).
- Original parts are worn and replacement cost is similar to upgrade.
- You ride heavier loads or more aggressive trails.
Popular Upgrades
- Replace leading-link elastomer with a coil-over unit: Some aftermarket companies offer conversion kits.
- Upgrade rear shock: Switch from a basic coil to a high-end air shock with remote lockout.
- Ti springs: Reduce weight slightly but improve responsiveness.
- Polyurethane bushings: Firmer than rubber; reduce flex.
What to Avoid
- Mixing incompatible brands: Stick with HP Velotechnik or reputable aftermarket brands like DT Swiss, Fox, or Suntour.
- Overspending on features you don't need: If you ride mostly paved trails, a basic suspension is fine.
Final Recommendation
For most riders, the priority should be maintaining the original suspension parts to keep them functioning like new. Replace elastomers and bushings proactively every 5000 miles or 2 years. If you crave more comfort or control, consider upgrading the rear shock first—it provides the biggest improvement. For front suspension, a leading-link fork with a tunable spring is a worthwhile upgrade. Always consult your HP Velotechnik dealer to confirm part compatibility, especially for older models.
By understanding the specific suspension parts and their roles, you can keep your recumbent trike riding smooth for years.