Gooseneck hitches
CURT Spyder fifth wheel to gooseneck adapter review
A fifth wheel head spreads a kingpin load across a set of jaws and a pivoting yoke. A gooseneck ball is a single point. Adapting one trailer type to the other mounting style means changing how that load actually reaches the trailer frame, not just changing which coupler shape is on top.
The CURT Spyder performs exactly that adaptation, letting a fifth wheel kingpin hitch to a gooseneck ball on industry standard rails. This review covers what CURT publishes for it, the structural tradeoff behind that convenience, and the question worth answering before buying one.
On this page
- What is the CURT Spyder, and how does the adapter actually work?
- How does the Spyder compare against a trailer-side conversion and two ball-mounted fifth wheel connections?
- What does CURT actually publish for the Spyder?
- What is the catch with concentrating pin load into a single ball?
- What are the alternatives that do not concentrate the load into a bare ball?
- What should you check before buying a fifth wheel to gooseneck adapter?
What is the CURT Spyder, and how does the adapter actually work?
The Spyder mounts to industry standard fifth wheel base rails and carries a welded 2-5/16 inch ball, so a truck already set up for fifth wheel towing can pull a gooseneck trailer, or a fifth wheel trailer kingpin can be hitched to that same ball. CURT rates it at 25,000 lb gross trailer weight, and it uses the same four-pin installation and removal as its rail-mounted siblings for easy bed access.
How does the Spyder compare against a trailer-side conversion and two ball-mounted fifth wheel connections?
The Spyder is a truck-side adapter. Set beside a trailer-side conversion and two products that mount a full fifth wheel head onto a gooseneck ball, the real question is where the load is concentrated, not which one carries more weight on paper.
| Published rating | CURT 16085 Spyder Fifth Wheel to Gooseneck Adapter, 25,000 lb | GEN-Y Nomad Fifth Wheel to Gooseneck Static Pin Box | Andersen Gen 3 Ultimate Fifth Wheel Connection Gooseneck Adapter, 24,000 lb | B&W Companion Fifth Wheel Hitch |
|---|---|---|---|---|
| Price | $291.64 | $749.95 | $1,154.98 | $1,099.00 |
| Gross trailer weight rating | 25,000 lb | not published | 24,000 lb | not published |
| Pin weight rating | not published | not published | 4,500 lb | not published |
| Ball diameter | 2-5/16 | not published | not published | not published |
| Mount type | not published | not published | Gooseneck ball mounted | Gooseneck ball mounted |
| Jaw design | not published | not published | not published | Cam action wrap |
Every figure here is the manufacturer's own published rating. A blank is a figure the maker does not publish, and we leave it blank rather than estimating it. The rating stamped on the part you actually receive is what governs.
What does CURT actually publish for the Spyder?
CURT rates the Spyder at 25,000 lb GTW, mounted to industry standard fifth wheel base rails with a welded 2-5/16 inch ball.
Published standard A published, traceable figure: a standards body, a federal regulation or a manufacturer specification states it.
| Published spec | CURT Spyder |
|---|---|
| Gross trailer weight rating | 25,000 lb |
| Ball diameter | 2-5/16 in, welded |
| Rail compatibility | Industry standard fifth wheel base rails |
| Installation | Four-pin, removable for bed access |
These are CURT published figures for the adapter hardware itself, not a statement about what a specific trailer manufacturer will approve.
What is the catch with concentrating pin load into a single ball?
The Spyder concentrates the pin load into a gooseneck ball rather than spreading it across a fifth wheel head the way the trailer manufacturer originally engineered it to be carried. That is a real structural difference, not a cosmetic one, and some RV manufacturers will not honor a frame warranty on a trailer towed this way. The warranty question is usually the deciding one: it is worth a call to the trailer manufacturer before buying an adapter, since a hitch rated at 25,000 lb does not settle a warranty dispute that has nothing to do with rated capacity.
What are the alternatives that do not concentrate the load into a bare ball?
A reader who wants a full fifth wheel head instead of a bare ball, and the SAE certification that comes with it, should compare the B&W Companion, which also mounts into a gooseneck ball hole but wraps the kingpin with a complete fifth wheel head rather than a single ball, or the Andersen Gen 3 Ultimate, a lightweight SAE certified fifth wheel connection built for the same style of gooseneck mount. Both keep the kingpin engaged with a proper fifth wheel style coupling, which is the structural difference a trailer manufacturer is actually asking about in a warranty conversation. A reader who wants to convert the trailer side instead of the truck side should look at the GEN-Y Nomad, a purpose built static pin box that replaces the kingpin assembly with a coupler engineered specifically for a gooseneck ball, rather than adding a generic adapter at the truck end.
What should you check before buying a fifth wheel to gooseneck adapter?
Contact the trailer manufacturer directly and ask, in writing, whether towing on a gooseneck ball voids the frame warranty before buying any adapter, since that answer decides more than any published GTW figure. Compare the structural tradeoffs of a bare-ball adapter against a full fifth wheel head using the fifth wheel versus gooseneck comparison, and once hitched, check pin weight against the fifth wheel pin weight calculator and the pin weight chart.
How we chose
We did not test this hardware in person and we never claim to. Picks are researched from manufacturer specification sheets, published towing standards, and the recurring themes in verified owner reviews. Every pick is matched to a real gross trailer weight rating, a real tongue or pin weight rating, a real receiver size or a real load index rather than to a price bracket, and it is placed in the tier where its published capability actually belongs. We rejected the unbranded flood that dominates the search results in several of these categories, because a weight distribution hitch, a brake controller, a trailer tire and a set of safety chains are all parts whose failure puts a loose trailer on a public road. Where a figure is towing convention rather than a published standard we label it that way, and where a manufacturer does not publish a figure we leave it out instead of estimating it.
Sources
- CURT published specifications for the 16085 Spyder
- GEN-Y Hitch published specifications for the Nomad
- Andersen Hitches published specifications for the Gen 3 Ultimate
- B&W published specifications for the Companion RVK3500
Frequently asked questions
Does the CURT Spyder void my fifth wheel trailer warranty?
It might. Some RV manufacturers will not honor a frame warranty on a trailer towed with the pin load concentrated into a gooseneck ball rather than spread across a fifth wheel head. Confirm the specific trailer manufacturer position in writing before buying an adapter, since this is usually the deciding question.
What is the published rating for the CURT Spyder?
CURT rates the Spyder at 25,000 lb gross trailer weight on industry standard fifth wheel base rails. That figure describes the adapter hardware itself, not whether a specific trailer manufacturer approves of towing that trailer on a gooseneck ball rather than a full fifth wheel head.
Why does a gooseneck ball adapter concentrate the load differently than a fifth wheel head?
A fifth wheel head spreads the kingpin load across jaws and a pivoting yoke engineered for that purpose. A gooseneck ball is a single contact point, so an adapter routes the same pin weight through a smaller, more concentrated connection than the trailer manufacturer originally designed around.
What is the alternative to an adapter if I want to keep a full fifth wheel head?
Products such as the B&W Companion or the Andersen Gen 3 Ultimate mount a complete fifth wheel head onto a gooseneck ball hole, keeping the kingpin engaged with jaws rather than a bare ball. That keeps the coupling style closer to what the trailer manufacturer engineered for, which matters for the warranty question.
Can I convert the trailer instead of adapting the truck hitch?
Yes. A product such as the GEN-Y Nomad replaces the trailer kingpin assembly with a coupler built specifically for a gooseneck ball, converting the trailer side rather than adapting the truck side. It still connects to a ball rather than a fifth wheel head, so the same warranty question applies.
Does the CURT Spyder require special rails?
No. It mounts to industry standard fifth wheel base rails, the same rails used by most rail-mounted fifth wheel hitches in this catalog, using a four-pin installation that allows the adapter to be removed for bed access when it is not in use.
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Researched, not professional advice. This page is compiled from published standards, manufacturer towing guides and product specifications, and owner-review consensus, not hands-on testing. Figures described as a rule of thumb are towing convention rather than published standards, and they are labelled that way wherever they appear. Nothing here overrides your own ratings. Work your payload sum before your tow rating, because payload is the limit that actually binds on most half ton trucks and nearly every SUV. Load a conventional trailer to 10 to 15 percent tongue weight and a fifth wheel to 15 to 25 percent pin weight, and never lighter: a tail heavy trailer is what starts sway. Weigh the rig loaded rather than trusting a brochure dry weight. A weight distribution hitch and a set of air bags both restore ride height and control, and neither one raises a single rating. Trailer brakes are required by state law above a threshold that varies by state, and a breakaway battery that has quietly gone flat is the normal condition of most trailers on the road.