The old 126105 FiberMax used FRP-skinned folding panels for the first-generation long-bed Colorado/Canyon. Current inventory now centers on newer generation-specific parts, so the old number is mainly useful when evaluating used or old-stock hardware.
Fitment first
What to confirm before buying
The legacy 126105 record points to a roughly six-foot long bed on first-generation Chevrolet Colorado and GMC Canyon trucks. Confirm the truck generation and measure the bed internally from the bulkhead to the closed tailgate. Do not use the FiberMax family name as evidence that a short-bed or later-body cover will fit.
Part 1126146 is listed for a 62-inch bed on a later Colorado and Canyon generation. Its FRP construction, 300-pound distributed-load claim, and included hardware describe that newer part only. None of those details should be transferred automatically to 126105 unless the original legacy documentation states the same specification.
When considering old stock or a used cover, verify the 126105 label on the assembly and identify both rails. Ask for photographs of every clamp, drain tube, panel seal, latch, release cable, hinge, and open-position support. A complete-looking stack of panels can still be unusable if its application-specific mounting pieces came from another truck.
Inspect the intended truck for unobstructed upper rails and viable drainage exits. First-generation vehicles may have replacement rail caps, drop-in liners, repaired beds, or added racks that were not present when the cover was cataloged. Resolve those interfaces through the original instructions rather than cutting a rare legacy kit.
Product at a glance
| Legacy part | BAKFlip FiberMax 126105 |
|---|---|
| Legacy application | First-generation Colorado/Canyon long bed |
| Current comparison | FiberMax 1126146 |
| Current comparison fitment | 2023-2026 5 ft 2 in bed |
How this accessory works in practice
BAKFlip FiberMax 126105 is a legacy part associated with the first-generation Colorado and Canyon long bed. Its defining construction is a fiberglass-reinforced polymer outer surface over an aluminum structure, used to create a rigid folding deck with better resistance to dents, scuffs, and dings than an exposed soft cover. The low-profile panels latch to side rails as they close and fold toward the cab when the bed opening is needed.
This page should help identify an older cover, not imply that a later FiberMax with a similar description replaces it. Part 1126146 belongs to a later-generation Colorado or Canyon with a 5 ft 2 in bed. It is a comparison product, not a fitment successor for 126105. Dimensions, rails, clamps, and application hardware remain tied to each individual part.
Daily use and ownership
The FiberMax closes panel by panel, with automatic latches engaging the rails. Release strings or cables under the cover allow opening from either side once the tailgate is lowered. Locking the tailgate then limits ordinary access to those controls. Check engagement at every panel because worn legacy latches may not produce the same clear action on both sides.
For tall cargo, the sections fold toward the bulkhead and can open the bed without removing the whole unit. Use the original struts, buckles, or retainers for the position being used, and confirm that those parts belong to 126105. Hardware shown for the later 1126146 cover is not proof that an older assembly can be secured in exactly the same way.
The FRP top resists common surface impacts and stays cooler to the touch than bare metal according to the archived material. Flush hinges and seals reduce paths for rain, dust, and snow, but they do not make the cargo box airtight. Keep sensitive items contained and prevent loose objects from striking the panel underside or release mechanism.
Installation and setup
Do not begin mounting until the cover label and complete hardware set have been verified. Locate the original 126105 instructions and sort left-side, right-side, and front hardware. Reject clamps with stretched threads, rails with a visible bow, detached hinge material, or drain fittings that cannot be secured.
Clean the truck's rail surfaces and place the matching FiberMax rails at equal height. Set clamps lightly, measure across the opening, and check that the rails remain parallel from bulkhead to tailgate. Integrated rail guides described for the FiberMax family can assist alignment only when the correct rails and components are present.
Position the folded cover, unfold each panel, and check side overlap, latch contact, and tailgate closure. If an old kit does not line up naturally, stop. Drilling, slotting, or pulling the rails inward to force a fit can hide the fact that the cover belongs to another application and can damage components that are difficult to replace.
Connect the drainage pieces supplied with the legacy kit and confirm a continuous downward route to existing bed exits. Test with a small amount of water, then fold and latch the cover several times. Recheck clamp location after a short drive and before relying on the cover for valuable cargo.
Care and maintenance
Wash the FRP skin with a soft mitt and mild automotive cleaner, paying special attention to particles lodged around the flush hinges. Clean the aluminum underside, rail ledges, and latch recesses without saturating release cables with heavy lubricant. Use surface treatments only when they are approved for both FRP and the cover's rubber components.
Age matters more than mileage for some legacy materials. Inspect hinge bonding, seal flexibility, cable ends, latch housings, drain fittings, and clamp threads. Store a removed cover flat and supported according to its instructions, not leaning on one panel corner. Address water paths by correcting alignment and seals rather than layering incompatible adhesive material over the joints.
Buy it when
- Your first-generation long-bed truck matches the verified 126105 application.
- The permanent label and both application-specific rails are present.
- All clamps, drains, latches, supports, and seals are complete and sound.
- You value FRP impact resistance and folding full-bed access.
Skip it when
- You expect 1126146 to serve as a direct replacement.
- The truck has a 62-inch bed or a later body generation.
- The used kit has unidentified rails or missing mounting pieces.
- You cannot obtain original installation and load guidance for 126105.
Frequently asked questions
Is 1126146 the replacement for FiberMax 126105?
No. The source material explicitly separates them. The legacy 126105 is tied to a first-generation long-bed application, while 1126146 is listed for a later-generation 62-inch bed. Shared construction and branding do not make their fitment interchangeable.
Can the newer cover's 300-pound rating be applied to 126105?
Not from these sources. The 300-pound evenly distributed figure is documented for 1126146. Use the original 126105 manual or manufacturer record for the legacy cover's limit, and never infer load capacity from panel appearance.
Which missing used-kit parts are most serious?
Vehicle-specific rails and clamps are critical, followed by latches, release hardware, supports, drain tubes, and seals. Replacing a generic fastener is different from reconstructing an unidentified mounting system. Confirm completeness before purchase, not after the panels arrive.
Why choose FRP over an aluminum outer surface?
The archived FiberMax material emphasizes resistance to dents, scuffs, dings, and surface heat while retaining an aluminum structure underneath. That can suit a working bed, provided the exact legacy kit fits and its aging hinges and hardware remain serviceable.
Related fitment guides
- BAKFlip G2 26121 for 2014-2015 Silverado 1500: Legacy Fitment Guide
- BAKFlip Tonneau Bed Covers: Fitment, Use, and Buying Guide
- BAKFlip MX4 448207 for Ram 1500 5 ft 7 in Bed: Fitment Review
Technical reference
Application and technical details were checked against Legacy 126105 specification record. Use the manufacturer application data and the vehicle’s own measurements as the final fitment check.