A bike rack cautionary tale

[WDavidG]

We recently departed a NC state park campground with two bikes on our relatively new Kuat rack mounted on the Scamp bumper. When we arrived 150 miles later at our next park site, all that was on the back of the Scamp was a broken stub of metal sticking out of the receiver. Rack and bikes were simply gone.

We were well below Kuat’s weight rating for the rack. So what went wrong? Poor engineering or incorrect fabrication on Kuat’s part? It was then of course that I first paid attention to the warning label on the rack - “Not safe for use on an RV”. Another case of operator error, not reading and heeding the manufacturer’s clear warning of the product’s limitations.

The critical and good news is that no accident was caused, no one was injured.

How I know that and how I was able to read the label after-the-fact is the really positive, kindness-to-strangers, element to the story.

Though we didn’t know it at the time, the rack parted ways from the Scamp on a quiet rural road about nine miles from our destination. A few minutes later a highway department crew passed us traveling the opposite direction, saw the rack and bikes in the road and surmised that it must have come from the car with the RV trailer and that said vehicle was probably headed for the local state park 20 minutes away. They loaded the bikes and rack on their truck and came looking for us, eventually finding our campsite and returning them to us. The bikes were amazingly unharmed (though transporting them for the remaining trip without a rack was a challenge).

I pass on this caution because, being diligent about tongue weight, we specifically purchased this rack because it is light weight (yet with sufficient capacity rating for our two bikes). We failed to pay attention to the RV-use warning. This Kuat rack has been mentioned on previous forums and others may also be using it and other manufacturers may have similar limitations on safe use of their racks. We also own a heavy-duty Yakima receiver-mounted rack and, reading the fine print in the instruction manual when we got home, discovered that it also warns against mounting on a trailer or RV. It is scary to think of the potential of a rack loaded with bikes snapping off on a busy highway. Please check the specs on your rack if mounting it on your trailer and believe it if the manufacturer says “don’t do it”.

(sorry the photo is sideways - the forum seems to rotate some of my pics when they are loaded)

[Gompka]

Thanks for the warning, i will have to take a look at my hollywood rack to see if there is a similar limitation. Its strange that it would matter if its mounted to a car or an rv, the only thing I can think of is that there is maybe more vibration present in the rv since the suspension is not as robust as that on a car/truck.

I just checked my rack and sure enough its not rv safe either, thanks again for the heads up HR200

[mary and bob]

The trailer bouncing and the leverage weight of the bikes is what usually causes the failure of the rack. I know of two that were mounted on the rear of a trailer that broke off, and one of mine bent. I have successfully used a rear rack on our Uhaul camper, but no longer do it, now that we tow with a truck the bikes go in the pickup bed

[Civilguy]

David,

Thank you, this is a very good post.

Is the part that failed aluminum?

[GregandTeresa]

We use the 1UP USA on the back of our Escape, and have loved it. It is one of the rare ones that are made to work on the back of RV's. So if you are looking for a replacement, take a look at those. But they are pricey...

[Jim Bennett]

Kuat makes a nice rack, but the fact they state it is not rated for RV use discluded from my search. Even if the rack welding was faulty, given their disclaimer unfortunately there is not likely much theft will do.

I previously owned a Swagman rack and a friend flooring me alerted me to the fact it was bouncing big time. It put too much wear on the bike frames too.

I have used a 1UP rack for 4 years now and can't say enough about them. Built strong, well engineered, and pricy but will worth it in my books.

[WDavidG]

Originally Posted by Civilguy

David,

Thank you, this is a very good post.

Is the part that failed aluminum?

Likely but I'm not certain. Kuat doesn't indicate but the break looked like aluminum and it seemed too light for steel. I threw it out at the campground so can't do a magnet test.

[John in Santa Cruz]

definitely looks like aluminum. further, that weld on the triangular brace doesn't have very good penetration across the top.

1Up and certain (but not all) Swagman racks are RV rated. I don't know of to many other brands.

[WDavidG]

I agree that the failed weld looked sketchy and maybe faulty but since I used the rack in manner not in accordance with their recommendation it's impossible to know if the failure was the weld or excess vibration. I'll let Kuat know and maybe they'll do a better job warning consumers. To their credit however, their warning was more evident than for my Yakima which hid it in the fine print at the bottom of the printed install instructions.

Thanks to several of you who suggested the 1up USA and Swagman. 1Up's website is silent on the trailer use question and I emailed them to ask. This is the response:

"Thank you for the inquire. We advise our 2" models only with a 2 bike max for RV and travel trailer usage."

I had asked about their "heavy duty" model and think this is the 2" reference. At 46 pounds it is definitely a heavy rack, not to mention pricey. But I'd prefer pricey to causing an accident. Haven't yet looked into the swagman.

[Mikmay]

What would be the difference being on the back of a Rv or a vehicle seems like it would fail in either case.

[Jim Bennett]

The back end of most any trailer will have way more bounce than a passenger vehicle, creating forces of havoc.

[k corbin]

If you are going to use a trailer hitch do use an anti rattle hitch tightening clamp to help stabilize the bike rack.

[WDavidG]

Originally Posted by k corbin

If you are going to use a trailer hitch do use an anti rattle hitch tightening clamp to help stabilize the bike rack.

Our Kuat and Yakima both have that function built in - many others may as well. Even so, I suspect the bouncing and vibration on the back of a trailer creates substantial additional stress (compared to the back of a vehicle) on a hitch. I'm inclined to believe that the manufacturer's engineers must have some data-driven reason for the caution about trailer use.

[Civilguy]

Originally Posted by WDavidG

Our Kuat and Yakima both have that function built in - many others may as well. Even so, I suspect the bouncing and vibration on the back of a trailer creates substantial additional stress (compared to the back of a vehicle) on a hitch. I'm inclined to believe that the manufacturer's engineers must have some data-driven reason for the caution about trailer use.

While this concern in regard to trailers as a general class seems understandable on the face of it, it's interesting that the two manufactures you mention apparently both extend the prohibition to "RV"; (did I understand that part correctly?)

"RV" includes self-propelled vehicles which I don't think of as bouncing around so much.

Oops; I see Mike (Mikmay) just said basically the same thing. Where's the 'embarrassed' emoji?

[tractors1]

Originally Posted by Mikmay

What would be the difference being on the back of a Rv or a vehicle seems like it would fail in either case.

Take a ride inside your trailer and you'll understand the difference, especially on speed bumps.

[Delmitch2]

I also have a Kuat NV that we use on our trailer; however, ours is mounted on a support on the hitch tongue. No issues with it being in this location. The rack is heavy and well-built, but I assume they have the warning for a reason. I have also heard very good things about 1Up, I like the simplicity of them.

[Jim Bennett]

Originally Posted by tractors1

Take a ride inside your trailer and you'll understand the difference, especially on speed bumps.

And specifically sit at the very back for the best effect.

[floyd]

Originally Posted by Mikmay

What would be the difference being on the back of a Rv or a vehicle seems like it would fail in either case.

ABSOLUTELY a huge difference! Any trailer is rough on bikes an a rear rack.
That's why mine is a tongue mount.

[WDavidG]

Originally Posted by Civilguy

While this concern in regard to trailers as a general class seems understandable on the face of it, it's interesting that the two manufactures you mention apparently both extend the prohibition to "RV"; (did I understand that part correctly?)

Mike:
Correct, they are explicit about both trailers and RV's generally. I am surprised as well.
Kuat: "Do not use this product on a recreational vehicle or trailer"
Yakima: "Do not install onto trailers, campers, or recreational vehicles"

[Tom 72]

In most cars you are suspended between two axles spread apart. Midpoint between axles sees the least movement, and smoothest ride. Trailers are the opposite. Most trailers are single axle, and even if they are double axle, the axles are very close together.

You would be hard pressed to design a vehicle with more movement at the back end. The motion is dampened somewhat by the hitch at the front. But most trailers are like rolling teeter totters.