CP106 Custom Fiberglass Rear Fender for Heavy-Duty Trucks

Product Overview

The CP106 is a custom fiberglass rear fender developed for heavy-duty trucks and commercial vehicle projects. It can be manufactured from an approved drawing, CAD model, existing part or physical reference sample.

The fender geometry can be configured around the vehicle’s wheel and tire size, axle arrangement, suspension movement, frame layout and available mounting points. Surface color and finish can also be specified according to the vehicle design or fleet requirements.

CP106 is an engineered-to-order component rather than a universal bolt-on replacement. The truck model, installation space and mounting arrangement must therefore be reviewed before tooling or production begins.

Custom Fender Configuration

Fender Profile

The fender profile must match the wheel envelope and the required area of coverage. Depending on the vehicle layout, a project may require a single-wheel, tandem-wheel, partial-coverage or full-coverage configuration.

The final profile is established from the approved project drawing. Existing fender samples can also be used when accurate CAD data is unavailable.

Width and Sidewall

Fender width affects tire coverage, installation clearance and the relationship between the fender and nearby chassis components. Sidewall height and shape may be adjusted to suit the selected appearance and installation method.

The design review should account for dual-tire width, wheel offset and lateral movement rather than relying only on nominal tire size.

Edge Design

Straight, returned or reinforced edge profiles can be evaluated according to the appearance, rigidity and mounting requirements of the project. Any edge that connects to a bracket or adjacent body panel should be defined before the mold is produced.

Decorative trim, lighting openings and other added features must be included in the approved design if required.

Truck Fitment Review

A fiberglass truck rear fender should be matched to the actual vehicle instead of selected by appearance alone. The following information is normally required:

• Truck manufacturer, model and production year

• Rear-axle configuration

• Axle spacing or spread

• Wheel and tire dimensions

• Single- or dual-tire arrangement

• Suspension type

• Normal ride height

• Maximum suspension compression and extension

• Existing fender or bracket dimensions

• Nearby air tanks, exhaust parts, pipes and electrical lines

• Required service access

• Left- and right-hand installation requirements

Photographs of the existing installation area are useful, but they do not replace dimensional drawings. Critical dimensions should be measured on the vehicle or verified through approved engineering data.

Wheel Coverage and Clearance

A rear fender helps limit the projection of water, mud and road debris from the rotating tire. Its effectiveness depends on the complete installation, including fender width, position, mud flaps and any additional spray-suppression components.

Adequate clearance must be maintained through the vehicle’s full operating range. The design should consider:

• Suspension travel under different loads

• Tire growth and deflection

• Axle movement

• Chassis twist

• Bracket deflection

• Snow, mud or debris accumulation

• Access for tire inspection and replacement

Insufficient clearance can cause the tire to contact the fender. Excessive clearance may reduce wheel coverage or produce an unsuitable appearance. The installation should therefore be checked at normal ride height and at the relevant suspension limits.

Fiberglass Construction

The CP106 uses fiberglass-reinforced plastic to combine molded geometry with a corrosion-resistant composite body.

Unlike unprotected steel, the fiberglass shell does not develop red rust. The resin system, surface coating and any metal brackets must still be selected and maintained for exposure to moisture, ultraviolet light, road salt and operating temperatures.

The laminate structure can be developed around the part geometry and expected mounting loads. Local reinforcement may be added around mounting areas when specified in the approved design.

Fiberglass can be repaired in many cases, but it is not immune to cracking or impact damage. Proper bracket alignment and distributed mounting loads help reduce localized stress.

Manufacturing Options

Hand Lay-Up

Hand lay-up can suit prototypes, replacement parts and lower-volume custom projects. It provides flexibility when the geometry or reinforcement layout requires manual control.

Resin Transfer Molding

RTM can be evaluated when the project requires more controlled molding, repeatable surfaces or medium-volume production. Tooling and part geometry must be reviewed before this process is selected.

Sheet Molding Compound

SMC is generally considered for stable, higher-volume programs where production tooling can be justified. Part design, annual quantity and performance requirements determine whether it is appropriate.

The manufacturing method is confirmed after reviewing the drawing, finish, production volume and tooling budget. Not every process is suitable for every fender design.

Mounting Integration

The fender and its support system must be considered together. Bracket position affects alignment, operating clearance and the loads transferred into the composite part.

Depending on the vehicle and maintenance requirements, the project may use fixed, removable or hinged mounting arrangements. Availability of brackets and installation hardware must be confirmed in the quotation.

Mounting points should:

• Distribute loads over a suitable area

• Avoid concentrated stress at unsupported edges

• Maintain clearance from the tire

• Allow for chassis and suspension movement

• Remain accessible for inspection

• Use corrosion-resistant hardware where required

Do not drill new holes or modify the fender before confirming the approved mounting locations. Incorrect drilling or bracket alignment can weaken the installation and affect fit.

Surface Finish

Available project finishes include gel coat, gloss, matte and painted surfaces. RAL colors can be evaluated when a specified fleet or body color is required.

Color matching should be based on an approved color reference because substrate, coating system, gloss level and production conditions can affect the final appearance.

For projects requiring final paint, the fender should be dry fitted before the complete coating system is applied. This allows the installer to verify clearance, bracket alignment and adjoining panel relationships without damaging the finished surface.

The selected primer, paint and preparation procedure must be compatible with the fiberglass substrate.

Prototype and Fitment Validation

A prototype or initial sample is recommended before batch production, particularly when the fender is being developed for a new truck platform.

The validation process may include:

1. Reviewing the vehicle and fender data.

2. Confirming the design and mounting interfaces.

3. Producing or adapting the required tooling.

4. Manufacturing an initial sample.

5. Dry fitting the sample to the vehicle.

6. Checking wheel coverage and dynamic clearance.

7. Confirming surface and color requirements.

8. Approving the part for batch production.

Any required change should be recorded in the drawing or sample approval document. This creates a controlled reference for future orders.

Heavy-Duty Vehicle Applications

The CP106 fiberglass rear fender can be developed for suitable applications such as:

• Heavy-duty road trucks

• Tractor units

• Tandem-axle trucks

• Semi-trailers

• Construction vehicles

• Agricultural transport vehicles

• Municipal and utility vehicles

• Special-purpose commercial vehicles

Suitability depends on the installation environment, vehicle geometry, operating conditions and applicable road regulations.

Technical Specifications

Dimensions, weight, laminate thickness, order composition, hardware and packaging are confirmed in the project quotation and approved technical documents.

Custom Project Workflow

Submit the Vehicle Information

Provide the truck model, year, axle layout, suspension type, wheel and tire size, photographs and available installation drawings.

Define the Fender

Confirm the required profile, width, sidewall, edge design, mounting points, surface finish and order quantity.

Review the Design

The submitted information is reviewed for mold development, manufacturing process, fitment and production feasibility. Missing dimensions must be resolved before tooling.

Approve the Sample

Where required, an initial part is produced for dimensional inspection and vehicle trial fitting. Sample approval establishes the reference for batch production.

Confirm Production

Production begins against the approved drawing, sample and commercial specification. Any later design change should be evaluated for its effect on tooling, cost and delivery.

Quality Control

Inspection requirements are defined around the approved product specification. Depending on the project, checks may include:

• Overall dimensions and profile

• Mounting-point position

• Surface appearance

• Edge condition

• Color and gloss

• Laminate condition

• Fit against a fixture or approved sample

• Packaging condition before shipment

The approved drawing, master sample or inspection standard should identify the acceptance criteria. Vehicle fitment remains part of the customer’s installation validation when XHY does not have access to the complete truck.

Frequently Asked Questions

Is the CP106 a universal truck rear fender?

No. CP106 is developed for an approved vehicle and mounting configuration. A similar-looking fender may not provide the correct tire clearance, axle spacing or bracket alignment.

How should an existing fender be measured?

Record the overall length, width, radius, sidewall height, edge profile and mounting-point locations. Include wheel size, axle spacing and clear photographs with a scale reference. A physical sample can be supplied when the shape is difficult to document.

Is the CP106 supplied individually or as a pair?

The order composition must be stated in the quotation. Confirm whether the project requires one fender, a left-and-right pair or a larger vehicle set before ordering.

Are mounting brackets included?

Brackets and hardware are included only when they are listed in the approved quotation. Existing brackets should not be assumed compatible without checking their dimensions and load distribution.

Can an old fiberglass fender be used as the development sample?

Yes, provided the sample represents the required geometry. Damage, distortion or previous repairs should be identified because they may affect the reproduced shape.

Can the fender be supplied ready for final painting?

Painted and other surface-finish options can be evaluated. The required color reference, gloss level and coating specification should be agreed before production. Dry fitting is recommended before final painting.

Can a damaged fiberglass truck fender be repaired?

Some cracks and localized damage can be repaired by a qualified composite technician. The part should be replaced if the damage affects mounting areas, structural integrity or safe wheel clearance and cannot be restored reliably.

How should the fender be cleaned?

Use water and a mild vehicle-cleaning product suitable for the supplied finish. Avoid aggressive solvents or abrasive tools unless the coating supplier confirms compatibility. Inspect mounting points and brackets during routine cleaning.

Does the fender automatically satisfy road spray regulations?

No. Compliance depends on the complete vehicle installation, including the fender’s width and position, mud flaps, spray-suppression devices and local rules. The vehicle manufacturer or system integrator must confirm compliance.

What determines tooling and production lead time?

Lead time depends on drawing completeness, mold requirements, manufacturing process, surface finish, sample approval and order quantity. A schedule can be issued after the technical information has been reviewed.