New AS Bike Rack, Hitch Receiver

[dznf0g]

Yes, distance up, and away are factors, as are weight of bikes, weight of rack, weight of receiver (to some extent). Slop in receiver to rack plays into the formula as well.

[Airstream Dad]

Good discussion!


Maybe what I'll do is run a line from the rack and tie it off somewhere, perhaps in the rear awning hardware, or even inside the rear compartment.

The Yakima rack is pretty stiff in the hitch receiver once you tighten the pin bolt, so there isn't a lot of action to create moment load, but perhaps tying it off will minimize it even further, or at least stabilize it during a shock, like hitting a hump or pothole.

OF course, I should probably be careful that the line doesn't do something like tear off the awning! I wonder if I should have a strong attachment point installed in the body, attached directly into one of the shell ribs, for instance. Might come in handy for other in-camp niceties like a clothesline or even a hammock.

Airstream Dad

[Snaken49]

Originally Posted by dznf0g

Yes, distance up, and away are factors, as are weight of bikes, weight of rack, weight of receiver (to some extent). Slop in receiver to rack plays into the formula as well.

I totally agree! A receiver mounted hitch extend out almost 10" from the trailer body to frame attachment seam. My Thule T2 extended out another 3 1/2' out from the bumper. The typical non-carbon mountain bikes weigh 26 lbs. x 2 = 52 lbs. A moderate up/down 3g acceleration (multiples the weight X 3) of a dip or bump in the road you suddenly have over 150 lbs. of weight (counting the weight of the rack) flexing in an arc at the end of a 4' arm. Over time this will cause significant damage to the AS. This is why AS does not recommend a hitch receiver bike rack.

AS recommended rack:

On the hand, the AS bike rack is mounted rigidly to both frame and structural members of the trailer close in to the end of the bumper. This greatly reduces the "arm" and potential of damage.

The video below from the AS customer service site provides a detailed installation guide for mounting the rack. About 3/4 the way through you will see that the top braces are firmly attached to the AS vertical frame members by 4, #10 screws (holes drilled into the frame).

An AS bike rack that is not attached in this manner is incorrectly installed, leading to potential damage to the trailer and loss of your bikes.

http://www.airstream.com/service/customer-support/

Hope this helps! :-)

[jdalrymple]

We have the Fiamma rack from AS. It works well. I completed the installation in about 2 hours, being very careful.

I would guess the weight of an empty steel rack that fits a receiver, as pictured above, is probably close to the weight of the Fiamma and 2 bikes.

But, the way the Fiamma carries the weight of the bikes is completely different than a receiver mounted rack. The wheel shelf is low and near the frame attachment points.

The rack on Wally’s trailer is much the same.

The receiver mounted rack acts as a big lever, transferring all the weight to a single point.

A receiver rack has the dough-pop flop action when the rear of the trailer bounces, no matter how little it moves when one tries to shake it. All the weight of the rack and bikes is suspended a fair distance from the rear of the trailer. When the trailer hits a bump in the road the rack flops, transferring stress loads into the frame of the trailer.

How much damage could one do to the rear of a trailer with a pry bar, prying against the rear of the trailer?

The Fiamma does put most of the weight on the frame, but much closer to the rear of the trailer than a rack designed for a receiver.

It also manages the flop factor by the attachments to the back of the trailer and the low, close mounted wheel shelf.

Just my thoughts.

Regards,

JD

[JamuJoe]

Originally Posted by Jim Clark

That may cause rear separation. Look at the approved AS bike rack and take note of the additional attachment points. You can find many threads debating the issue you have to judge for yourself. I went with the approved AS bike rack because I did not want to create warranty issues on a new trailer. I do like the concept it has been around for years just never would risk the intergearty of the shell to frame joint. BTW The AS bike rack has a 75 lb weight limit which is 2 bikes which tells me AS did not want to push the envelope to much.

The Fiamma AS Bike Rack transfers all of it's vertical force to the rear chassis beams and bumper. The shell/frame attachment points provide lateral stability and some counterforce to the horizontal component of the cantilevered force. Not a bad design, but it in no way reinforces the shell to chassis attachment. The main concern with a receiver hitch mounted bike rack would be to minimize the distance between the rear of the trailer and the load, as the cantilever force increases with every inch, creating a bending moment on the chassis. Older models with less chassis strength apparently suffered when such loads were applied.

[Rorschach]

Any updates from the OP on how this hitch is performing?

Inquiring minds would like to know...