Single Piece Order Inline Spring Fork Assembly for Custom Springer
Fitment Verified Front End Depth — We manufacture this inline spring fork assembly in-house, confirming the 18″ length against your custom build platform before dispatch.
Product Specification
| Parameter | Value |
|---|---|
| Part Type | Inline Spring Fork Assembly |
| Length | 18″ |
| Stem Diameter | 1″ |
| Thread | 1″ x 24 |
| Finish | Chrome (legs, outer springs, rockers), Zinc plated (rocker studs) |
| Kit Contents | Front and rear legs, outer springs, rockers, rocker studs |
Fitment
| Platform | Year Range | Notes |
|---|---|---|
| Custom Springer | Confirm with model and year | Length measured from the top of the rear leg (tube) to the front axle center line; rear fork leg is not tapped. |
Independent aftermarket part. Not manufactured, sold or endorsed by any motorcycle manufacturer. Model names and OEM numbers are used for fitment reference only.
Defining the Measurement Baseline for Your Build
The 18″ length is measured from the top of the rear leg to the front axle center line.
When sourcing an inline spring fork assembly for custom springer projects, builders often overlook the measurement baseline. I once saw a builder order an 18-inch fork without specifying where the measurement started. The supplier measured from the stem, but the frame geometry required the distance from the rear leg top to the axle centerline. The resulting rake and trail were completely off, causing the front tire to rub the fender. Always verify the exact length over stock and the measuring points against your frame specifications [NEED_CITE: frame geometry measurements for custom springer builds].
Verifying Stem and Thread Dimensions
Matching the steering neck is just as critical as the overall fork length. This inline spring fork assembly for custom springer features a 1″ stem diameter with a 1″ x 24 thread. If your top tree or steering stem nut does not match this exact thread pitch, the assembly will not seat correctly. Always cross-reference your existing steering neck components to ensure the 1″ x 24 thread aligns perfectly with your setup [NEED_CITE: steering stem thread specifications across custom frames].
Understanding the Neck Diameter and Plating
The bottom of the neck on this assembly is intentionally larger in diameter to accommodate the lower bearing race. Before attempting to mate this fork with your steering head, you must check the threaded and bearing holes for excess plating. Chrome buildup in these critical areas can prevent the bearing from seating flush, leading to steering binding or improper alignment. Inspect all threaded and bearing surfaces carefully to ensure a smooth fit.
The Hidden Cost of Unchecked Geometry
Ordering a fork without confirming the measurement baseline or stem thread often leads to severe assembly delays. If the 18″ length does not match your frame’s intended ride height, the front end will sit too high or too low, ruining the stance and handling geometry of the build. Similarly, if the 1″ x 24 thread is ignored, the top tree cannot be secured, leaving the bike stuck on the lift. These fitment mismatches force builders to halt production, reorder parts, and waste valuable shop time resolving issues that could have been caught during the initial quotation [NEED_CITE: assembly delays caused by incorrect front end dimensions].
Sourcing Directly from the Manufacturer
We produce this inline spring fork assembly in our own facility, ensuring direct control over the chrome finish and zinc plating quality. Our front-end depth allows us to supply complete assemblies alongside early springer and hydraulic fork parts under one account. We offer chrome and black finish options to match your build’s aesthetic requirements. Every fitment is confirmed against your platform and year range before we issue a quotation. With a minimum order of just one piece, you can source a single sample for fitment confirmation before committing to a bulk order for your shop.
Documentation and Shipping Details
- Fitment sheet stating the Custom Springer platform and confirming the 18″ measurement baseline.
- Cross-reference sheet with OEM numbers marked reference only.
- Key dimensions including the 1″ stem diameter, 1″ x 24 thread, and overall length.
- Finish specification detailing the chrome legs and zinc plated rocker studs.
- Quality inspection record and warranty terms included with every dispatch.
Pre-Installation Inspection Checklist
- Verify the kit includes front and rear legs, outer springs, rockers, and rocker studs.
- Confirm the 1″ stem and 1″ x 24 thread match your top tree requirements.
- Check threaded and bearing holes for excess chrome plating before installation.
- Note that the rear fork leg is not tapped and requires separate axle hardware.
- Ensure the bottom neck diameter accommodates your lower bearing race.
Request a Fitment Check
Send your model and year for a fitment check to ensure this 18″ fork matches your custom frame geometry. Provide your steering neck specifications to verify the 1″ x 24 thread compatibility. Let us know if you require a single sample for test fitting before placing a larger order for your shop.
Frequently Asked Questions
Q: How is the 18″ fork length measured on this inline spring assembly?
A: The 18″ length is measured from the top of the rear leg down to the front axle center line. This specific baseline ensures the fork matches your custom frame geometry and maintains the correct ride height. Always confirm this measurement point against your frame specifications before ordering to avoid rake and trail issues.
Q: Which additional parts need to be ordered separately for this fork?
A: This inline spring fork assembly is completely assembled but requires you to order the bearing neck kit, axle kit, top tree, and handlebars separately. The rear fork leg is not tapped, so you must source the appropriate axle hardware to complete the front end setup for your custom build.
Q: What should I check on the threaded and bearing holes before installation?
A: You must check the threaded and bearing holes for excess plating before installation. The bottom of the neck is larger in diameter to accommodate the lower race, and any chrome buildup in these areas can prevent proper seating. Carefully inspect all surfaces to ensure smooth operation and correct alignment.
Q: Can I order a single sample to confirm fitment on my custom frame?
A: Yes, we support a single piece minimum order for custom builders. You can order one sample to verify the 1″ stem diameter, 1″ x 24 thread, and 18″ overall length against your specific frame geometry. Once the fitment is confirmed on your build, you can proceed with bulk orders for your shop or distribution.