Chrome Narrow Spring Fork Assembly 20 Inch – Fits Custom Springer
Fitment Verified by Platform — Every narrow spring fork assembly is checked against your frame’s steering neck and rocker spacing before dispatch.
Product Specification
| Parameter | Value |
|---|---|
| Part Type | Narrow Spring Fork Assembly |
| Finish | Chrome |
| Length | 20″ |
| Stem Diameter | 1″ |
| Axle Outer Diameter | 3/4″ |
| Width Between Rockers | 6″ |
| Leg Thread | 3/4″-18 |
| Kit Contents | Triple tree, 1″ stem, brake boss, 3/4″ axle, standard fittings |
| Side Offset | Left side rocker offset |
Fitment
| Platform | Year Range | Notes |
|---|---|---|
| Custom Springer builds | Confirm with model and year | Left side rocker is offset to allow space for applications where a brake system is installed. Accepts standard Spring Fork components. |
Independent aftermarket part. Not manufactured, sold or endorsed by any motorcycle manufacturer. Model names and OEM numbers are used for fitment reference only.
Resolving Rocker Width and Axle Spacing in Custom Builds
A 6″ rocker width and 3/4″ axle clear standard front wheel and brake setups.
When sourcing a narrow spring fork assembly for custom springer projects, builders frequently encounter clearance issues between the fork legs and the front brake caliper. A standard inline setup often leaves zero margin for a disc brake rotor, forcing the wheel to sit off-center or the caliper to rub the rocker. This 20″ assembly shifts the left side rocker outward, providing the necessary physical gap for brake system installation without altering the right side alignment. Verifying this offset dimension against your specific wheel hub and brake mount prevents the front end from binding during assembly [NEED_CITE: frame geometry and brake clearance specifications for custom springer builds].
Checking Triple Tree and Stem Alignment
Before welding or clamping, the 1″ stem diameter must match your frame’s steering neck bore exactly. The inline top triple tree design ensures the 20″ fork length drops straight down, maintaining the intended visual rake. If the stem is even slightly undersized, the steering head bearings will shift under load, causing unpredictable handling. Always measure your frame’s neck inner diameter and compare it to the 1″ stem specification to guarantee a secure fit [NEED_CITE: steering head bore dimensions across custom springer frames].
Verifying Leg Threading for Riser Mounts
The fork legs are drilled and tapped 3/4″-18 to accept your chosen risers. This specific thread pitch is critical for securing the handlebars without stripping the aluminum or steel legs under vibration. If your existing risers use a different metric or imperial thread, they will cross-thread or fail to seat. Confirm your riser hardware matches the 3/4″-18 specification before attempting installation to avoid damaging the new fork legs.
Understanding the 20″ Length and Axle Diameter
The 20″ overall length dictates the final ride height and visual proportion of the front end. Combined with the 3/4″ axle outer diameter, this assembly supports standard custom front wheels. An axle that is too thick will not slide through the wheel bearings, while one that is too thin will allow the wheel to wobble. The 3/4″ axle paired with the 6″ width between rockers ensures the wheel is centered and the brake components have adequate room to function [NEED_CITE: axle and rocker spacing tolerances for springer front ends].
The Cost of Overlooking Offset Dimensions
Ordering a springer assembly without confirming the left side rocker offset often results in the bike sitting in the shop for weeks. If the offset is missing, the brake caliper will physically interfere with the fork leg, requiring custom machining or a completely different front end. This delay halts the build schedule and incurs additional labor costs to resolve a fitment issue that should have been caught during the specification phase. Ensuring the 6″ rocker width and offset match your brake setup prevents these costly workshop bottlenecks.
Sourcing from a Front-End Specialist
We manufacture our springer front ends in-house, allowing us to control the 6″ rocker width and left side offset directly. Every narrow spring fork assembly is verified against your frame’s steering neck and rocker spacing before it leaves our facility. We offer this 20″ unit in a chrome finish, with consistent plating quality across batches. You can order a single piece for a one-off custom build without meeting high minimums. We also cross-reference your existing parts to ensure the 1″ stem and 3/4″ axle match your requirements.
Documentation and Shipping Details
- Fitment sheet listing the custom springer platforms and year ranges this assembly was checked against.
- Key dimensions document detailing the 20″ length, 1″ stem, and 6″ rocker width.
- Finish specification confirming the chrome plating standards for this batch.
- Quality inspection record verifying the 3/4″-18 leg threads and left side rocker offset.
- Packing photographs showing the triple tree, brake boss, and standard fittings included.
Receiving and Pre-Installation Checks
- Verify the kit includes the triple tree, 1″ stem, brake boss, 3/4″ axle, and standard fittings.
- Confirm the left side rocker offset is present to ensure brake system clearance.
- Measure the 6″ width between rockers and compare it to your front wheel and brake setup.
- Check the 3/4″-18 leg threads to confirm compatibility with your chosen risers.
- Inspect the chrome finish for any shipping damage or plating defects before assembly.
- Store the assembly in a dry environment to prevent corrosion on the exposed threads.
Requesting a Fitment Check
Send your frame model, year, and a photograph of your current steering neck to verify the 1″ stem fitment. Provide the outer diameter of your front axle and the width of your brake caliper to confirm the 6″ rocker width and left side offset are correct. Let us know if you require a sample unit for physical trial assembly before committing to a larger batch for your shop.
Frequently Asked Questions
Q: How do I confirm this 20″ narrow spring fork fits my custom frame geometry?
A: Measure your frame’s steering neck bore to ensure it matches the 1″ stem diameter. Check the distance between your frame’s tree mounting points to verify the triple tree spacing. Finally, confirm the 6″ width between rockers accommodates your front wheel and brake setup without interference.
Q: What are the critical dimensions to measure before ordering a springer assembly?
A: You must measure the steering neck bore for the 1″ stem, the available space for the 20″ fork length, and the width of your front hub to ensure the 3/4″ axle and 6″ rocker width are compatible. These measurements prevent clearance issues during assembly.
Q: Does the left side rocker offset accommodate standard brake caliper mounts?
A: Yes, the left side rocker is specifically offset to create physical clearance for standard brake systems and caliper mounts. This design prevents the caliper from rubbing against the fork leg, allowing proper installation of disc brake setups on custom builds.
Q: Can I order a single spring fork assembly for a one-off custom build?
A: Yes, we support single-piece minimum orders for custom builders and repair shops working on one-off projects. You can order this 20″ narrow spring fork assembly individually, and we can provide a sample for fitment confirmation before you proceed.
Q: What components are included in the spring fork kit?
A: The kit includes the inline top triple tree, 1″ stem, brake boss, 3/4″ axle, and standard fittings. The fork legs are pre-drilled and tapped 3/4″-18 for mounting risers, providing the core hardware needed to assemble the front end.