16Victor

I have to transport my tandem on a one-way trip about 5 hours on the freeway.

The car is a Volvo XC90 with factory 'aero' roof racks. I have a pair of roof mount bicycle holders (stock Volvo - Thule). Since this is a short term need, I attached the two racks end-to-end by riveting some struts underneath the joint.

The cross rails are spread as far as they can be and I mounted the long rack to them backwards. This was so the bike would be over the car and not hanging over the windshield. This also lets me open the hatch fully.

I fixed the rack directly to the cross rails by drilling a hole in the rack and attaching it with T-bolts to the slot in the cross rails.

Not being happy with the side-to-side stability, I attached a rope to the captain's seatpost and tied each side the the rack. See pic and ignore goofball photobombing son.

Seemed OK on a very short neighborhood drive.

Would you trust this setup on 5-hour freeway drive?

Darth Lefty 

Your photo doesn't work for me. Is that my problem?

What will your rig do in a panic stop? When you grab the tire and push up and down, does it rock?

16Victor

Not sure why the photo doesn't appear. Works on Firefox, not Internet Explorer. Will have to try something else.

yamsyamsyams

Photo not working on iOS.

socalrider

I have a volvo with factory thule rack and was able to find a tandem mount via craigslist.. The new tandem mounts are 400-600, I was able to get this older model for $50.00 and a few extra parts bought at Home depot have made it a perfect rack for my new tandem.

DCwom

As Darth Lefty points out its not the steady state load you should be concerned about, it may seem fine on the short around the town test you've tried. You could take the setup to a mall parking lot, (Sunday nights are good because stores close early) and do some hard stops, swerves, etc to test stability. Keep in mine that a failure may damage the vehicle and/or bike, but that's better at home than on a highway somewhere.

geranimo57

The link for the photo is https: if you right click and open in new tab, ignore the warning and proceed it will open.

Team Fab

Since this is a one off(and I cant see the pic either) why not just lie it down on some foam on the rack?

Darth Lefty 

I certainly don't want to sign on to a recommendation to swerve around in a parking lot on Saturday night to see if your car and bike break each other!

I'd want the CG of the bike right between the rails. I get it about the hatch - my WRX had scars in its spoiler from skis and snowboards. And you should have seen that car with a 17 foot canoe on it. Can you arrange it so the spoiler hits tire and not rack?

FBOATSB

I cringe whenever I see bicycles verticle on a roof rack flying down the interstate. Just make sure an altered rack system does not void your insurance.

16Victor

Ummm...because I spent a few hours doing my handiwork and I just have to see it succeed. Truly.

Now, will I be stupidly stubborn about it? Hopefully not so much as to damage my bike and car. But I'll give it a good shot.

Thanks for this and the other comments. I think the rope gives me some added confidence. I will test it again under more severe circumstances with a spotter.

I got it as close as I could; I wanted the rails under each touch point but the bolt holding the rack to the cross rail was directly under the back tire (front of car...the bike is pointing backwards). Had to slide the cross rail forward a bit.


No negatives with the hole drilled through the rack and attaching it via a t-bolt to the cross rail? Seems a shaky polar moment of inertia but I am not experienced with roof racks, let alone one with a 40lb tandem on top.

BTW, once this trip is done, the rack halves separate to their original single-bike form and they go on my WRX (well, actually, Saabaru).

Much thanks [beer]

JanMM

Tandem Topper doesn't center the bike's COG over the rails but it's a rugged beast.

OneIsAllYouNeed

I suspect this trip already happened. How'd it go?
If I attempted something similar with two single-bike racks, I'd place the fork-mount as close to a roof bar as possible, since that spot handles all the torque (from cross winds, etc). Single bike racks aren't as torsionally stiff as tandem racks.

The rear wheel strap only handles gravity load, so it doesn't need to be particularly stiff.

The straps from roof bars up to the captain seatpost were a good call. I suspect they saw quite a bit of tension at times.

andr0id

I think your big issue is that the front QR mount on tandem specific racks are really beefy.

If you tandem weighs in the neighborhood of a heavy single that the rack is designed for, then you are probably OK. But you should be looking at the max weight for 1 rack and staying under that number.

16Victor

The trip was made 2 days ago. Went well. Here are some pics of the setup:

The cords to the captain's seatpost were absolutely essential. Had to keep them taught.





This is the joint where I riveted the u-channels underneath. Good enough for a temporary job but no way it's enough for sustained use. Should have riveted the sides too.


The wheelbase was greater than the distance I could spread the cross rails so the above bending was inevitable.


Remember this was a temporary setup. As soon as I got home I drilled out the rivets in the channels that connected the two racks and they were returned to normal service as single racks.

I picked up a lightly used Thule Tandem Carrier 558P for $160 to the door and it's going on soon.

Thanks for all the input. Lesson: a well done jury rig is still a jury rig so get the right stuff for long term use.

JanMM

Thule Tandem Carrier is a re-branded ATOC Tandem Topper. Good Choice. Great price.

velocentrik

You're potentially going to kill someone with your kludgery.

Your posts here demonstrate deliberate premeditated negligence.

Chancy

Velocentrik,


I think you are being harsh and reckless with your comment. Can you backup your statement with sound proof, science, metallurgy? The DIY temporary tandem carrier worked and killed no one! Yes, the rack bowed in the middle due to the mounting points, for the bike, being beyond/outside of the cross rails. This put an upward strain on the middle of the center rail (butt joint) and they moved...until the riveted strap (underneath) took up the stress and limited the movement. With the riveted strap now carrying the stress he may could have gone another 10 hours or 10 years using this setup and the gap, butt joint of the individual rails, may not have grown whatsoever. We don't know.


Tailwinds,
Charlie
2016 Santana Beyond

16Victor

That's asinine. I have a degree in engineering and 30+ years in the machine tool industry. My hobbies have centered around making and fixing all manner of things since I was about 8 years old. Very few failures and none remotely fatal.

The proof is in that it worked for its intended purpose and duration, and well.

Nya nya.

Team Fab

And the obvious point. Tandem was still attached to the car. Even if rack broke in the middle tandem was not going anywhere. Sure would damage your car, but that would be it. In the event of a major car accident this set up was probably more likely to keep the tandem with the car than a traditional rack due to the strings.

merlinextraligh

Why?

I can personally vouch for this setup at 110mph. and 1.1 lateral g's (admittedly not at the same time)

16Victor

What a shame.