Custom Springer Fork Assembly 18″ Narrow – Fitment Checked
Front end depth verified — complete springer assemblies and multiple over-stock lengths checked against platform dimensions before dispatch.
Product Specification
| Parameter | Value |
|---|---|
| Part Type | Custom Springer Fork Assembly |
| Finish | Black with chrome springs |
| Overall Length | 18″ |
| Stem Diameter | 1″ |
| Axle Outer Diameter | 3/4″ |
| Rocker Width | 6″ |
| Leg Thread | 3/4″-18 |
| Kit Contents | Triple tree, 1″ stem, brake boss, 3/4″ axle, original fittings |
Fitment
| Platform | Year Range | Notes |
|---|---|---|
| Not stated in source | Not stated in source | Confirm with model and year. Verify 6″ rocker spacing and 1″ stem for narrow custom profiles. |
Independent aftermarket part. Not manufactured, sold or endorsed by any motorcycle manufacturer. Model names and OEM numbers are used for fitment reference only.
Why Rocker Width Dictates Tank Clearance on Narrow Builds
A 6-inch rocker width defines the steering envelope for narrow custom setups.
When builders request an 18″ narrow spring fork assembly for a tight chassis, the rocker spacing directly determines handlebar and tank clearance. I remember a builder ordering a springer front end for an FLSTS Springer Softail. He just asked for an 18-inch over stock fork. We shipped a standard width assembly, but he was building a narrow setup. The rockers were too wide, and it rubbed right against his tank. Since then, I always double-check the 6-inch rocker spacing and 3/4-inch axle specs for these narrow Tedd-style forks [NEED_CITE: frame geometry and tank clearance tolerances by build style]. Measuring the 1-inch stem and verifying the overall length prevents those costly clearance headaches.
Verifying Steering Neck and Axle Alignment
Before quoting, we check if the 1-inch stem diameter matches the steering neck bore and if the 3/4-inch axle aligns with the front wheel hub. The top triple tree features standard stem and tube locations, inline to accept dog bone or stock Spring Fork handlebars. If the stem is oversized or the axle spacing is off, the assembly will not seat properly, leading to binding or misalignment [NEED_CITE: steering head bore and axle spacing variations across custom frames].
Brake System Clearance and Offset Rockers
The left side rocker on this 18″ narrow spring fork assembly is offset to allow space for brake system applications. This specific geometry ensures the caliper and mounting hardware clear the fork leg without interference. Builders must confirm this offset matches their specific brake setup, as standard rockers may not provide adequate room for certain aftermarket caliper mounts [NEED_CITE: brake caliper clearance requirements for offset springer rockers].
Decoding the 3/4″-18 Leg Thread
The legs are drilled and tapped 3/4″-18 specifically for mounting risers. This thread pitch and diameter dictate which riser hardware can be used to achieve the desired handlebar height and pullback. Using incorrect risers can strip the threads or leave the handlebars unsupported, compromising the front-end structure.
The Hidden Cost of Unverified Front End Dimensions
Ordering a springer without confirming the rocker width or overall length often results in parts sitting on a shop bench. A mismatched 18″ narrow spring fork assembly means the bike remains on the lift while the builder waits for a replacement. Furthermore, if the kit is missing original fittings like the brake boss or specific axle hardware, the build halts entirely, causing project delays and additional freight costs [NEED_CITE: supply chain delays caused by incomplete front end kits].
Sourcing Front Ends with Confirmed Dimensions
We produce front-end and chassis parts in our own facility, ensuring the 6-inch rocker spacing and 1-inch stem are machined to specification. Our catalogue offers complete springer assemblies and multiple over-stock lengths, allowing builders to select the exact profile needed. We verify fitment against platform and year range before quotation, and cross-reference against Harley-Davidson OEM numbers (reference only) to ensure compatibility. Minimum order from one piece supports custom builders and shops building single bikes.
Documentation Included with Your Shipment
- Fitment sheet stating applicable platforms and year ranges for this assembly
- Cross-reference sheet with OEM numbers marked reference only
- Key dimensions including fork length, rocker width, and stem diameter
- Finish specification detailing the black finish with chrome springs
- Quality inspection record verifying the 3/4″ axle and 3/4″-18 leg threads
- Packing photographs showing the triple tree and original fittings included
Pre-Installation Checks for the Shop
- Verify the kit includes the triple tree, 1″ stem, brake boss, 3/4″ axle, and original fittings
- Measure the 1″ stem and 6″ rocker width against your steering neck and tank clearance
- Check the black finish and chrome springs for any transit damage before mounting
- Confirm the left side rocker offset aligns with your specific brake system setup
- Ensure the 3/4″-18 leg threads are clean and ready for riser installation
- Store the assembly in a dry environment to protect the finish before fitting
Requesting a Fitment Check for Your Build
Send your model and year, along with a photograph or measurements of your current steering neck and axle spacing, for a fitment check. Let us know if you require the black finish with chrome springs or if you need a sample unit to verify the 6-inch rocker spacing before committing to a bulk order. We will confirm the 18″ narrow spring fork assembly matches your specific custom profile and provide a quotation.
Frequently Asked Questions
Q: How do I confirm if this 18″ narrow spring fork assembly fits my specific custom build?
A: Send your model, year, and a photograph or measurements of your steering neck and front wheel hub. We verify the 1-inch stem diameter and 3/4-inch axle spacing against your frame specifications. We also check the 6-inch rocker width to ensure it clears your tank and handlebars before providing a fitment sheet and quotation.
Q: What key dimensions should I measure to ensure the triple tree and axle match my front end?
A: Measure the inner diameter of your steering neck to confirm it accepts the 1-inch stem. Check the width of your front wheel hub to ensure it aligns with the 3/4-inch axle. Additionally, measure the available space between your frame and tank to verify the 6-inch rocker width provides adequate clearance for your specific setup.
Q: Does this narrow spring fork kit include the necessary fittings for headlamp brackets and shock assemblies?
A: Yes, the kit includes original fittings designed to accept original Spring Fork components, including headlamp brackets and shock assemblies or ride control hardware. The triple tree features standard stem and tube locations, inline to accept dog bone or stock Spring Fork handlebars, ensuring all mounting points are covered for your build.
Q: Can I order a single sample unit to verify the fitment and finish quality?
A: We support a minimum order from one piece, allowing custom builders and shops to order a single sample unit. This lets you verify the 6-inch rocker spacing, the 1-inch stem fitment, and the black finish with chrome springs quality before placing a larger bulk order for your inventory or multiple builds.
Q: How does the offset left side rocker affect brake system installation on custom builds?
A: The left side rocker is specifically offset to provide necessary clearance for brake system installations. This design ensures the caliper and mounting hardware do not interfere with the fork leg. You must confirm this offset matches your specific brake setup, as it alters the lateral space available compared to standard, non-offset rockers.