I would say its more like a bounce , not shake.

I have thule atlantis 1600xt it has a claw that you tighten with a knob from inside box.

When I take my hand and move the front of box the rails just doesn't seem strong enough front rail flexes a lot. Seem like its only good for a short box as someone mentioned a few replys ago.

Before next road trip I will get thule crossbars and that should solve the bounce since I will be able to have a wider spread and a stronger bar.

 

Thanks for the link. No clear pic of how the bar connects?
The clamping device is the part I am curious about, 2 nuts on a u-bolt?
Are the mounts quick release or permanent mount?
Looks like a possible solution to a bike mounting problem for me.

 

My cargo box uses a different type of clamp instead of the claw type for the Thule system. This type of clam seems to lock completely around the oval OEM cross bar with no space or wiggle room. I wish there was more "structural integrity" with my carrier because there is still some flex in the whole box when I shake it to test the tightness of the clamp. I think this where my bouncing is coming from when on the Hwy. I give my type of cargo box .

 

^One thumb nut on an L shaped clamp. Interesting.

Anyone add Thule cross bars to an oem rack? Any pics of the cross bar to rack connection?

 

This is what the thule mounting is like...

 

If you are not comfortable with the bounce, there is nothing to do.......BUT, I would recommend that you check the installation and tightness of the crossbars to the car, something may be loose in there.
I don't think that installing new bars will solve the "bounce" (probably reduce it a bit if you are able to spread the mounting points a bit more) because you still have a cantilever portion of the box in front of the crossbar that when hit by wind at 80mph will necessarily bounce, its just physics. The factory bars are not the greatest, but they will withstand the load that they are rated for, they are not going to just "snap".

 

^^Thanks, 2 jaw one thumb wheel. Will it tighten with no slack or looseness?

 

Not just the box to the bars, but the bars to the car (rails)
Let my try to explain....not sure I'll be able to...
the crossbars allow for a sort of in and out play as the car (rails) are not the same width in the front and back. If you moved the bars to the front, or maybe during the installation they did, the bar may be a bit loose, or there may not be enough grip from the piece that holds it in place...it works like a clamp that holds the crossbars in place....I'm not saying that that's the issue, but it's worth checking.
think about this, if the bars are solidly attached to the car, how would a different set of bars make a difference? rather, that much of a difference?

 

I checked all is tight , the 4 torx screws that you tighten on the cross bars to secure to side rails are all secure. I really think with Thule crossbars which i will be able to move 3 inches more forward then the oem bar will help with the bouncing.

I was meaning to call Thule to see if I am correct in saying the max load will be 165 lbs. With their crossbars attached to oem rails, as opposed to 110 lbs with oem set up.

If that is the case that will be another reason to buy them. Will let you know what they say.

 

The way I understand it is that whenever you are towing or carrying something, the load capacity is that of the lowes rated piece of the package. If the OEM is rated at 110, is that for the crossbars alone? Or is that for the rails too?
Thule would probably offer something to attach directly to the roof of the car too....
Good luck solving the bounce.

 

I think the OEM crossbar and rails are rated at the RDX max at 110lbs (50 kg). Even if you go aftermarket, 110lbs would still be the max weight you can place on top of the RDX roof safely. It is kinda like tires with max pressure being 55 psi and the vehicle recommends 32 psi for safe operations. Putting 165 lbs on the roof could damage it and/or increase roll over if you had to do an emergency maneuver. No matter how strong the aftermarket crossbars/rail are, the RDX roof is still the weakest link.

I would go with the Thule system if it solves your bouncing problems; but, stick with 110 lbs max weight.

 

This is the full Thule rack set up. Very solid, tight and surprisingly quiet.

 

What was the part number and how much did this setup cost you?

Was thinking about getting this but have been putting this off since forever.

 

The aero bars were 53 inchers. And the base mounting kit for the Traverse base was #1550. The whole setup with locks was about $900 but this was after the 20% off sale at REI. I believe they have a Thule sale once or twice a year.

 

I have the same box, love it. On OEM setup pics on this thread.

It seems like your front cross bar is above your sunroof? On OEM you can only go as fwd as right aft of sunroof.

 

Yes the crossbar is on top of the sunroof. That's how the box can clear the rear antenna.

 

Awesome set up! Was going to re-use an evolution 1800 for the RDX that's been on a Pilot, S60, LR3 and Sequoia albeit with non aero traverse. And patched togethor with epoxy & dryer sheets but that's another story....My worry was forward overhang, and garage roller door clearance. Think I'm good for overhang. Nothing left to do now but order....

 

Factory bars on most cars & trucks suck esp with big boxes. The bounce could be flex. Aftermarket bar will help for sure.

 

I have a Thule Ascent 1500 mounted on a Whispbar rack. The Thule mounting system works great, very pleased with the box thus far. We'll be taking it on its first long haul in a couple weeks so I'll know a bit more at that point but based on capacity, price, quality...would totally recommend this one.

 

I want one