Race Tech Fork Tube Springs for Harley Models

• Race Tech fork springs
• Preload spacer material
• Spring shims and spacer

Here is a list of the spring rates supplied for each kit based on Fork Size and Rider Weight.

Note: These spring rates are recommendations based on aggressive/stung riding styles. If you would like a softer of stiffer spring than the recommended, please select it accordingly.

39mm Forks:
Rider Weight — Spring Rate
155lbs and Under — 0.85kg/mm
156lbs - 175lbs — 0.90kg/mm
176lbs - 205lbs — 0.90kg/mm
206lbs and Up — 0.95kg/mm

41mm RH975 Nightster Forks:
Rider Weight — Spring Rate
155lbs and Under — 0.95kg/mm
156lbs - 175lbs — 1.00kg/mm
176lbs - 205lbs — 1.00kg/mm
206lbs and Up — 1.00kg/mm

49mm Forks Dyna & M8 Softail Models:
Rider Weight — Spring Rate
155lbs and Under — 0.95kg/mm
156lbs - 175lbs — 1.00kg/mm
176lbs - 205lbs — 1.10kg/mm
206lbs and Up — 1.20kg/mm

49mm Forks Touring Models:
Rider Weight — Spring Rate
155lbs and Under — 1.10kg/mm
156lbs - 175lbs — 1.20kg/mm
176lbs - 205lbs — 1.30kg/mm
206lbs and Up — 1.40kg/mm

High-Performance Fork Spring Upgrade
Replaces the factory fork springs with rider-weight-based performance springs for improved front-end control and ride quality.

Spring Rates Based on Rider Weight
Allows riders to select a spring rate that better matches their weight, riding style, and performance needs.

Improved Comfort and Control
Helps improve front-end support, braking stability, cornering confidence, and overall suspension feel.

High Stiffness-to-Mass Ratio
Engineered for strength, responsiveness, and efficient suspension performance without unnecessary weight.

Chrome Silicon Steel Construction
Made from shot-peened, heat-treated, and preset chrome silicon steel for durability, consistency, and long-term performance.

Accurate Rates Within 2%
Designed with spring rate accuracy within 2% for predictable performance and proper suspension setup.

Built for Accuracy and Performance
Race Tech fork springs are engineered to deliver consistent, reliable suspension performance for riders upgrading their stock front forks.

Supports Multiple Harley Applications
Available for several Harley-Davidson fork sizes and models, including 39mm, 41mm, and 49mm fork applications.

Fits select Harley-Davidson models depending on fork size and application:

• Harley-Davidson Dyna & Sportster models with 39mm forks
• Harley-Davidson Dyna & M8 Softail models with 49mm forks
• Harley-Davidson Touring models with 49mm forks
• Harley-Davidson RH975 models with 41mm forks

Always select the correct fork size, model application, and rider weight option before ordering.

What do Race Tech Fork Tube Springs do?
Race Tech Fork Tube Springs replace the factory fork springs with high-performance springs designed to improve front-end support, comfort, control, and handling.

Are spring rates based on rider weight?
Yes. These springs are available with rates based on rider weight so the suspension can better match the rider and riding style.

What are these fork springs made from?
They are made from shot-peened, heat-treated, and preset chrome silicon steel for durability and consistent performance.

How accurate are the spring rates?
Race Tech fork springs are designed with accurate rates within 2% for predictable suspension setup and performance.

What Harley models do these fit?
These springs are available for select Dyna, Sportster, M8 Softail, Touring, and RH975 models depending on fork size.

What fork sizes are supported?
Fitment options include 39mm, 41mm, and 49mm fork applications.

Will these improve ride quality?
Yes. Properly selected fork springs can improve comfort, front-end support, braking stability, cornering confidence, and overall suspension feel.

How do I choose the correct spring rate?
Use the Spring Rate Guide and select the weight range that matches the fork spring rate you wish to receive. Riding style, gear weight, and setup may also influence spring rate selection.

Is professional installation recommended?
Yes. Professional installation is recommended to ensure proper fork disassembly, spring installation, preload setup, oil level, and front suspension performance.