truck rack - advice

Help! I am looking to mount 2 yakima cross bars on my small truck - a toyota tacoma. One installer helping me has suggested mounting one bar on the roof of the cab, and the second bar on top of the topper (after installing a rain gutter mount on the topper). Sounds great, but I am wondering about the effect subtle shifts in movement between the truck bed (and hence the topper) and the truck’s cab may have on the kayak load? Is it better to mount both rack on the topper? Also – we are traveling with 18’and 17’ boats. Any thoughts on the correct spacing of the bars given this load? Finally… has anyone every loaded 3 boats onto bars like this? I know it’s not ideal, but we’re trying to make do with the options we have available, without busting the budget. Many thanks!

My truck is set up just as you described
My F-150 is set up just as you described, a rack mounted on the cab,and a Yakima rain gutter mount on the camper shell for the rear rack.

The forward rack on the cab is mounted to the rear of the cab, right where the rear edge of the doors are. The rear rack on the camper shell is mounted about as far back on the shell as I could get it, giving me a little over 8’ space betweeen the bars.

I carry two canoes with my truck, and there is no movement between the cab and camper shell. Canoes ride good.

This is the second truck I’ve racked up with a camper shell, and both worked good.

The only problem you might have is if you have one of those camper shells with a “High Rise” back, not flat and even with the roof of the cab.

I can vouch for this also
I had my truck set up the same way. The only thing I did was reinforce the cap’s attachment to the bed, because the dealer was chintzy with it.

Also not a problem
I have the some set up on my Tacoma. As far as spacing, if you are carrying kayaks, try to get a bar under each bulkhead.

Whew. All of this is a relief to hear. Anybody ever load 3 kayaks onto these kinds of bars? Thanks

Don’t say there is “no movement”

– Last Updated: May-05-10 10:10 PM EST –

You just haven't looked very closely. I post on this topic a lot, and have provided typical amounts of movement, both flexural and torsion, that can be expected in normal driving, on steep driveways, and off-road driving. There's probably no ill-effect on most boats, most of the time, but you can bet that the distance between your front and rear rack shortens by almost an inch on severe bumps. It happens super-fast and it's hard to see, but less-severe shortening of 1/4 to 1/2 inch is easy to see, IF you look for it. I think a lot of modern "not really a pickup" trucks have less differential movement at that bed junction because the bed is so tiny and the cab is so huge. Since a much greater proportion of the total length is devoted to the cab, they approach the point of having a car-like condition of body stiffness as a result. Also, the 'joint' where this motion occurs is much closer to the rear axle, not centered between the axles like on a normal pickup (the closer you get to an axle location, the less frame flex there will be AT that location).

This is the sort of thing that only a person who's interested in frame flex will bother to notice, and part of the reason it's hard to see is that your line of sight gets knocked around (it doesn't take much of a bump to jiggle your head too much) when on bumps. If you have faith that there's no movement between the cab and topper, I dare you to put a bolt through the front wall of your topper at the roof line and lock it there with nuts so it ends just 1/4 away from the edge of the roof of the cab, and then go for a drive! I "double-dare" you to do that with a heavy load in the box.

I would put one bar on the roof above the cab, the I’d get a hitchmount tower with a bar on the other. This will minimize any movement, and be further apart thus more secure.

no, it won’t
A hitch mount rack will move much more than a cab mount rack. Before you tell me I don’t know what I’m talking about - I’ve tried both.

Really?..I’d have your truck looked at then. A truck’s hitch is mounted to the vehicles frame. A trucks bed moves quite a bit but the frame and hitch wont move at all. The hitch and cab are much more static than any other part of the truck.

hitch mount rack
Have you used a hitch mount rack?

You’re right that the hitch doesn’t move with respect to the frame, but a wobbly bar stuck in the hitch, and extended 5 feet up moves a ton, IMO.

Rack on the Cap and Cab is the best solution, I’d say.

thank you
Exactly. Anyone who has actually used a hitch-mount riser and rack would know that (but he’s going to come back and call you stupid for not welding the hitch mount to the truck!).

A hitch mount WILL have a lot of wobble

– Last Updated: May-05-10 10:13 PM EST –

..unless it's an all-welded system with reinforced joints (no right-angle bolted connections).

That said, a wobbly hitch mount is not necessarily such a bad thing, as having one cross bar that's "loose" and free to move a little bit will actually prevent any stress from being imparted to the boat when there's flexing between the truck cab and the box (caused by flexing between the front and rear halves of the FRAME), though it WILL mean the boat has to pivot a little bit, back and forth on each cross bar as the hitch mount wobbles. Anyway, I wouldn't say a hitch mount is bad, only that it's wrong to say there's no movement. Even a simple drawbar plugged into the hitch receiver will have a good 1/8 to 3/16 inches of wobble, and even more out at the ball end, except on drawbars that are rusted-in (usually you can hear the darn thing rattling in the receiver when pull a trailer on a bumpy road). Multiply that amount of wobble by several times, to account for the tall cross-bar support, and that's how much wobble you'll have at the top.

Oh, and this:

"A trucks bed moves quite a bit but the frame and hitch wont move at all"

is totally wrong. The cab is mounted to the frame via rubber cushions, but the box is a direct, metal-on-metal, bolted connection. The reason there is movement between the topper/box and the cab is BECAUSE the frame is flexing. There'd be no reason for the cab or box to flex in the absence of stress imparted by the axles, and the axles are attached to the FRAME, not the body. The frame actually flexes less when reinforced by the body, but where two body sections are unattached (box and cab), that's where flexing and twist is most-clearly seen. All trucks have flexible frames, from the smallest pickup to the most heavy-duty Oshkosh military trucks. In fact, frame flexing accounts for a certain amount of the diagonal differential suspension height when on uneven terrain (it's not just the suspension that lets the wheels conform to uneven ground). The Mercedes Unimog is available in pickup-like body styles, but it is a much sturdier truck than any pickup you can get, yet its body is attached to the frame in such a way as to ALLOW the frame to twist, unencumbered by the stiffness of the body, and that improves the Unimog's off-road capability. The only way to eliminate flex would be to build the frames like trusses, and that would take up valuable space needed for the body, and besides, they work just fine being a little flexible.

I’m not going to come back and call you stupid…that’s your personality, not mine. I have a yakima hitch mounted tower and when it’s in my receiver hitch you can do pull-ups on one side and you will experience ZERO movement in the bar…Zero meaning none, as in none at all. It is rock solid and wont move AT ALL. The fact that you’re arguing it means you’ve never seen one. Stop being so childish already, you two are still bent about the obese thread. Grow up. I could care less how you carry your boats, or if they fall off your vehicle. Ask a question, get an anwswer. How lonely are you that you need to argue everything I post??

Wrong…you know what a truck is dont you?

So predictable

– Last Updated: May-06-10 12:44 AM EST –

Yes, not only do I know a thing or two about trucks, I've been practically obsessed with the design features of their frames and suspensions since I was just a kid.

Since you clearly didn't understand what I said, or are convinced it couldn't be right, check some on-line sources about this. If you do an internet search using keywords like "pickup", "frame" and "flex", you will get thousands of links. I know because I just tried it. Among them are some really involved discussions among off-road enthusiasts, talking about the merits of various frame designs, and which ones flex the most and which the least (note that I used the word "least", rather than some term indicating no flex at all).

I've driven a whole bunch of different pickups and 'carryall' trucks (nowadays they call them SUVs), and when they were parked on uneven ground in real off-road situations, not a single one of them had properly fitting doors because the frame was a little bit twisted. Sure, you could open and close the doors just fine, but if I was familiar with the vehicle, I could tell they didn't fit quite right, with the latches binding a noticeable amount during closing and opening. One of the off-road discussions I just read was about how much more torsional flex there is in a Toyota with a C-channel frame than a modern F-150 with a box frame, and supposedly, if you support the Toyota on two diagonally-opposite wheels, the tailgate falls open because the frame flex causes the box to warp too much to keep the latch engaged (not sure which Toyota model that was, and plenty of other trucks would probably do the same thing when twisted that way). Finally, if you do the search I suggested, you will find a bunch of statements like this one: "A pickup truck is a light motor vehicle with an open-top rear cargo area (bed) which is almost always separated from the cab to allow for chassis flex when carrying or pulling heavy loads." Similar "definitions" explain that in the absence of that separation between the box and cab, frame flex would cause the sheet-metal body panels to warp, meaning that the separation between the cab and box is NEEDED in order to accommodate the flexing of the frame during normal use of the vehicle.

If you don't believe me, do some reading on your own. I've never searched this stuff on-line before, but I'm fascinated with truck design. For years I've been noticing how bumps in the road, heavy loads, and the use of load-equalizing hitches combined with very heavy trailers cause pickup truck frames to bend, and in my construction-related job I watch the frames of trucks of many different kinds flex during off-road situations on nearly a daily basis, if work is busy enough for me to be on jobsites that often.

Here's one trivial observation of mine regarding frame flex in light trucks. In all the years I've been watching pickup-truck frames bend and twist, there were only TWO models in which that flex could be considered a design flaw. The first was the last style of Ford F-100s, before that model was discontinued. F-100s made around 1978 to 1980 had frames that were so flexible, simply driving them diagonally into a steep driveway would cause the box and cab to be misaligned by about 6 inches, and a 150-pound person (me at that time) standing on one end of the rear bumper would twist the box-cab joint out of alignment by about two inches. That particular model of F-100 had a series of closely spaced holes down the length of each frame rail, with the holes having a diameter nearly as great as the vertical dimension of the rail, so there wasn't much steel in the frame at all. The other truck with too much frame flex was the first run of Chevy 1-ton pickups and 1.5-ton trucks of the brand new style of the late 80s, when they first made the switch to independent suspension on front-drive axles. In special long-wheelbase versions of those trucks, the center of the frame would sag about two inches when carrying a full load. Take a look at any modern Chevy model 3500 and notice that there's an extra chunk of steel welded to the center portion of each frame rail, right where the box and cab come together. They first added that bit of reinforcement to address the frame-sagging problem back around 1993 or so, and even though the newer frames are stronger, they still use that feature to make them stiffer. I can name a few other pickup models which had what looked like "excessive" flex, but were at least perfectly capable of doing what they were designed to do, even though they'd often develop a permanent sag (which gave them the appearance of being "bent" in the middle). These were also models from several to many years ago, and I haven't seen any modern pickups in that category.

Folks are overthinking this…

– Last Updated: May-05-10 11:30 PM EST –

....Until a week ago I drove Toyota (Pre-Tacoma) trucks for 35 years and carried all manner of boats. I exclusively used Yakima Wide Loaders/Side Loaders mounted on canopies. While I always thought about the advantages of a longer spread and considered mounting the forward rack on the cab I never did.

I never had a problem with not setting the boat so that it was supported at the bulkheads (but I wondered). Sure, I did it when I could but I didn't worry about it. I never had any boat damage to any 14' to 18' boats because of having less than 6 feet of bar spread. Heck. Five is is lots! The only place where having that forward rack would have improved the quality of my life (while having no effect on the life of the boats)is when I travel on PNW ferry boats where there is a surcharge for any vehicles over 7 feet high and 20 feet long. I turn them upside down, stern first and slid forward to go through the ticket booth and that's the only place where having a cab mounted rack would matter to me.

Ditto, but instead of rain gutter mounts
use Yakama “Landing pads” boolted right through the cap roof, and also through or into the cab roof.

They have ones for cars and trucks that if you have a double wall roof, are made similar to a toggle boat, so they never come through the inner roof and you don’t see them on the inside of the vehicle.

On the other hand if your truck just has a single wall roof, use the same ones for the cab and cap.

I have had them on my 2003 truck since it was new, and have carried three boats for 90,000 miles at high speeds.



A front truck hitch will wobble
With todays trucks there is no movement between the cab and the bed unless you are carrying a couple tons of sand or concrete block, in which case you might get a fraction of an inch movement.



No one is "overthinking " it.
the OP ask questions and we who have a lot of experience answered the questions.



I didn’t start the argument

– Last Updated: May-06-10 10:03 AM EST –

...and I didn't question you on your truck. I merely stated I've tried both, and testified to my experience and every hitch-mounted rack I've seen.
I don't need to say anything negative about you. I don't find anyone else in agreement with you yet, your provocative nature and your posts here and elsewhere put your record on display.
When anyone else at all supports you, then I'll take you seriously.