More roof rack questions...

…I presently drive a station wagon where the cross bars fit into fixed slots on the roof rails. The longitudinal distance between the two cross bars is 28 inches and this seems to work well for my seventeen foot kayak.

However I currently have the hots for a small two seater sports car. The manufacturer’s roof bars are designed to fit into slots in the upper section of the door frame. This puts the cross bars about twenty-two inches apart. This means the tie down straps will be getting pretty close. Does anyone know if that’s cutting things too close?

BTW, I always use bow and stern lines for roof transport.

Too close
Doing this from memory, I believe the Thule fit guide states 25" as the minimum spread for carrying a kayak/canoe. That said I know of a couple of local paddlers that have Miatas and VW GTIs that use Trailex SUT250 (or the 200) model trailers to tote around their boats. Gets quite a number of looks driving around. Good gawk factor.

See you on the water,


The River Connection, Inc.

Hyde Park, NY

Short roof adapter kit
I think both Yakima and Thule offer them.

Thanks Marshall…
…seems like 22" might be pushing it. I’m a one car person and would hate to have to pick up a separate set of wheels just to do some boat haulin’.

I’m just not feeling the trailer :slight_smile:

I’ll check them out…
…currently using a Yakima J cradle setup which has been pretty good on the wagon with the exception of a couple of strong cross-wind days.

kayak pro
What about that v carrier thing I see advertised on this site. I think kayak pro makes it. It looks like it would work with any spread. I’m feeling really good about the six foot spread on my truck right now. Good luck.

Ryan L.

…checked out the Thule 887xt slipstream and I may have to get one. I really hate how my current j-cradles position my boat on its side where it catches the cross winds so nicely.

My daughter had the same problem,-
and got either a Yakima or Thule (not sure which) “Slip Stream” which allows the bars to be much farther apart.

She carries a 18 foot Epic kayak with no problem

check it out

jack L

…I’ll have to switch over to them. I’m getting a small Audi and luckily found some new OEM cross bars designed specifically for the car for about $94. They retail for around $370. Looks like the 887xt’s can be had for under $250.

Thanks guys, for pointing me in the right direction. Looking forward to warmer weather so I can load up my RockPool and get inverted without freezing :slight_smile:

21’ rowing shells on mini cooper

If that…
…can be done on the Mini, then I should be good to go with the 887’s. I’ll have to check the overhang and see if I’ll need to flag my arse to keep it legal. Very helpful image.

EZ-Vee on Mini

– Last Updated: Jan-18-11 12:47 AM EST –

I recommend the Kayakpro EZ-Vee, it's nicely engineered of welded aluminum with internal stiffeners in the square sections. Not cheap, but mine is 4 yrs old and going strong. A little more than the Thule, but less kludgy, fewer small parts to break.

I added a second this past summer for a road trip to Cape Breton. I'm always the first one racked up and ready to roll.

I’ll check that out
It looks like a very clean arrangement with less stuff to go south. A few extra bucks is not a big deal when it comes to securing a rooftop load.

Thanks muchly for the image links.

sure, why not

Now, for a bit of critical thinking - what happens when the cross bars are very close together (think about torque and forces, they will act on both the boat and your car). How will those forces change if mount points on your car remain as before while you implement cradle extenders for your boat?

It might be a little hard to visualize all the twisting and shouting, just for experimentation bring those cross bars on your rack to 22 inches, try to twist your kayak and observe.

Oh, didn’t you say that you were not totally happy with wind a windy day with 17 footer on your wagon?

A bit more info
I have a memory that Audi factory crossbars are the same aero style as those for the Mini. If so, adapters from 2x3 aluminum tube will hold it all together. These photos show some detail:

What’s your point?
It’s hard to tell what you mean from your post - do you think using an EZ-Vee or Slipstream is worse than just saddles on the crossbars? Or do you think a 22" spread won’t work in any situation?

There’s not much difference whether a twisting force on the rack is caused by a 17’ boat on cradles 22" apart, or a 17’ boat on an 8’ EZ-Vee, except that the EZ-Vee is solidly attached to the crossbars, and the front of the Vee can be well-secured to the front bumper, so the boat does not carry the twisting load, the carrier does. Seriously, my racks never move at all, and the boat is basically unstressed during transport, at least compared to saddle or J-cradle mounting.

my point?
Very simple - it doesn’t matter how much spread you get on the hull of 17ft boat, the spread on roof is still 22inches.


– Last Updated: Jan-18-11 2:16 PM EST –

That part at least was clear - so do you think a car with 22" spread should not be used to carry a 17' boat? If so, it's not necessarily clear from what you wrote - why hint around if that's what you think?

Who knows, you may be right. A 22" spread will certainly experience more torque on it than one with 33" spread if all is the same, but my point was that an extended carrier can be secured independently of the boat up at the front, effectively reducing the torque transmitted to the roof attachments.

An interesting and forceful twist
It does seem in one sense that the forces on the (22") crossbars will be the same no matter if the boat is directly attached to the bars or indirectly attached through the medium of an extension device.

What about the forces on the boat (probably mainly the yaw forces)? Carl says you can minimize these by tying down the extender to the vehicle. But you could also tie the boat directly to the vehicle by using lassos.

It would help clarify things if we could identify the dangerous forces, on what bodies, in the base case (no extender device).

As a thought experiment, let’s reduce the crossbar spacing to 0 – that is, there is only one bar. Is there any difference between tying the boat directly to this one bar or indirectly via an extender?

I’ll answer myself: down force
Staying with the one bar thought experiment, I see a clear difference in handling down forces by using an extension device. By down forces, I mean those forces that tend to pitch or pull the ends of the boat downward.

If the hull is balanced on the single cross bar (in a saddle if you like), there will have to be bow and stern lines that pull down on each end of the hull. The typical inverted V lines will do this because they impart a downward anti-pitch force vector as well as a sideways anti-yaw force vector.

These down forces will stress the hull, which has a huge leveraged overhang over the roof crossbar. I’d be concerned about bending or fracturing the hull by snugging these lines too tight.

However, if an extension device is used, most or all down force on the hull can be eliminated. If the extension device is long enough, like the ones used for rowing shells, the snug lines can be attached directly to the extension. Hence there will be no stressful down force on the hull at all.

If a shorter extension is used the snug lines may still have to be attached to the hull, but the hull overhang beyond the extension will be much less than the hull overhang beyond the roof crossbar absent the extension. Hence, even with a short extension there will be much less leveraged down stress on the hull created by snug lines.

Therefore, I believe an extension device is a worthy idea because it can reduce or completely eliminate the hull stressing down forces created by snug lines.

Next, will an extension device reduce sideways yaw forces? I don’t think it does at the roof cross bar connection, for the reasons stated above. However, I think the answer is yes at the snug line connection. What I mean is that, if you can eliminate or reduce down force on the hull by using an extension device, you can snug your inverted V ropes much tighter than you would if the ropes were secured directly to the hull. This will naturally allow your snug ropes to give you a stronger anti-yaw static force vector.

Assuming this makes mechanical sense so far, I am led to conclude that the best extension device is one that is long enough for you to affix vertical inverted V ropes to it and your vehicle.