Distance between top of cab and bottom of cabover?

[Durango1]

So I'm speccing out the customer flatbed build for my Hawk and the company is willing to build it as I wish. So while I want the lowest possible height (don't we all?) I don't want to have the cabover scraping my cab roof on a tough trail. My gut tells me the closest I should go is 2"? What do you all suggest?

Thanks,
Steve

 

[Stalking Light]

If you go off road your truck frame will flex and twist, how much depends on the truck and the terrain of course. 2" seems pretty tight to me. There's about 5" space between my Tacoma cab and my Eagle, probably more space than required but one less thing to think about on a trail. If you are 100% highway then 2" would probably work. Just my $.02.

 

[MANXMAN]

I would agree with Stalking Light. 2" is too low if you plan on off pavement use.

I set mine to 3" and it seems to be about as close as I would want it.

 

[wuck]

With my used Hawk on a new F250 the cabover actually touched the cab when first installed. I built a spacer from 2x4's, so I now have 1.5". I did 60 miles out and back on the White Rim trail recently, didn't have any problems there. I've seen a thread or two here where owners install cabinets under the cabover to store solar panels, you might want to check them out.

 

[buckland]

For what it's worth. We go a lot into the wilds of North Maine woods on very rough log roads. I have an 01 Tacoma and an Eagle 2011.
I built an under the cabover cabinet for the solar panel and then an aluminum air foil which has improved my milage 1.5 mpg. It is about 1.5" from cab with no problems over 3 ½ years.

 

[craig333]

Tightest spot on mine is 1 1/2". Never been a problem.

 

[Advmoto18]

While the frame of a truck is designed to twist and flex some, I think any flex more than an 1" in the ladder style frame would be an anomoly. I believe the camper will twist and flex far more than the truck's frame due to assymetric loading.

I'd call the FWC home office and ask to speak to the resident engineer. I don't know his name. He CAD/CAM a camper frame modification for Jonathan Hanson's (OX owner) FWC camper after a flexing incident cause the camper skin to crack. I suspect the FWC engineer would offer the best guidance for truck cab to camper cleararance distances.

Check out Stan's post and pictures from OX-West. Click on the Dropbox link for pictures. Scroll through the pictures for the RAM with the FWC Grandby Flatbed. A super nice rig! The flatbed was very nicely done by the fabricator. However, there were a few issues the owner noted after all 3 components were mated (truck, flatbed and camper). Granted a Grandby is installed on a long wheel base, but, think very cafefully through the details designing your truck's flatbed.

Seeing the Grandby flatbed in person, my first thought was, it APPEARED top heavy to my eye and would the rig traverse the difficult trails I like to travel? While the RAM 3500 is more than capable of carrying such a payload, I would likely consider some HD sway bars and bushings over OEM, even with a Hawk FB.

(edited) Found the link and pics...

One of the issues I seem to recall, when the owner and fabricator designed the storage box at the front of the flatbed, the flatbed did not extend far enough aft to fully support the bottom of the camper. Personally, I would only hire a flatbed fabricator utilizing CAD/CAM software able to input payload data and adhere to truck manufacturer's CG specifications for carrying a camper.

Plenty of clearance between cab/storage box and bottom of camper.

 

[Durango1]

Thanks everyone for your responses. I wrote the factory asking for their suggestions. I'll post back with what they say. Any more suggestions from our members would be welcome too!

 

[Durango1]

So I went out and measured what my Hawk is now from the cab roof and it is 3 1/4". However, given that the Flat Bed model inevitably sits higher (about 6") I'm aiming for 2" to 2 1/2" and the FWC factory got back to me and said given the rigidity of their cabover that shouldn't be a problem. Will keep everyone posted.

 

[sunvalleylaw]

What did you guys use to adjust your spacing? I have been researching, and I see some people use wood (2x and ply) and others incorporate high density XPS insulating foam sheets. Thoughts?

Here is mine with an inch and a half after adding some temporary 2x. Thinking I would like a half to 1 inch more.

 

[camper rich]

I also raised my Grandby up 1-1/2" to acomodate a 3-1/2" box I made to carry my Extend and Climb ladder. I also have a Eazy Awn stainless steel table under the overhang. Truck is a Dodge 2500 short bed Quad Cab. Cab clearance is 1-1/2" and never had a problem off road. Frame on the 3/4 ton is probably stiffer than on the 1/2 ton trucks.

 

[sunvalleylaw]

I also raised my Grandby up 1-1/2" to acomodate a 3-1/2" box I made to carry my Extend and Climb ladder. I also have a Eazy Awn stainless steel table under the overhang. Truck is a Dodge 2500 short bed Quad Cab. Cab clearance is 1-1/2" and never had a problem off road. Frame on the 3/4 ton is probably stiffer than on the 1/2 ton trucks.

Thanks! If you don’t mind sharing, what did you use to raise the Grandby? I am thinking I will add a 3/4 inch sheet of ply and arrang the two by to support the wood framing already there under the camper and screw it all together.

 

[camper rich]

I used 2 x 3's laying flat to make the frame.

 

[kmcintyre]

You need to know what type of truck you have or might have as some trucks like mine, have the satellite receive shark fin up on the roof AND if you ever get/have a sunroof it takes space.

 

[sunvalleylaw]

You need to know what type of truck you have or might have as some trucks like mine, have the satellite receive shark fin up on the roof AND if you ever get/have a sunroof it takes space.

Mine is a 2010 Dodge Ram 2500. It has the sat receiver up top, but is not a fin. It is flat and flush with the surface of the roof. But it is now covered by the camper top (it is on the back portion of the cab roof) so need to move it, or install a different one.

 

[bryanmichaelmeyer]

I love this post as I stumbled upon the rack linked below while I was continuing my three year search for some easy solutions for the space between my cab over and cab. With my Eagle I had a good 5ish inches. With my Fleet on its way I assume it is going to drop a significant amount. I am probably going to order one of these after I get my fleet so I can have some storage in front of the cab over and slide some maxtrax under the cab over. They say it only adds 2.75 inches to the cab!!

http://www.prinsudesignstudio.com/product-page/2005-2017-toyota-tacoma-cabrac

 

[bike4mee]

Sure would like to see your (Buckland) plans for that cool curved spacer/ wind deflector.

 

[PackRat]

I have an 8' bed on my 1988 F-250. I bought an older Alaskan and when I went to pick it up, I had made a pallet out of 5/8" plywood and some 2x6s consisting of a "ladder" design under the plywood so that there was cross support in three places plus the front and rear pieces. So make that five "rungs" if the ladder description works for ya. I screwed the plywood down with the side/end 2x6s right at the edge to insure support where the side of the Alaskan met the floor. In this, we are doing the same kind of pallet design I think.

As it turned out, I did not need so much lift and when I get to it, I plan to raise the camper and remove the pallet. I think I will keep the Bedliner in there but have yet to decide to go with just the plywood or with just the "ladder" underneath it.

While the plywood will be suspended above the "ridges" in the Bedliner, allowing for water to run back out...it will also allow moisture to wick in between the wood floor and the plywood and that is not a good idea! I will probably go with the 2x6 "ladder" framework and remove the plywood. I will have to decide if I want to install some insulating foam in the spaces in between the 2x6s or not. If I do, I will need to insure that it will be thick enough to seal against the floor but still allow air to circulate beneath the foam and for rainwater to run out. However, since I'm not going to spend that much time in severely cold climes...my priority is not to allow the floor-to-sidewall joints to get wet & rot.

With that in mind I can either keep the 2x6 ladder system or do as others have done and get some 1/2" x 4" or so redwood slats to spread across the floor and at the sides of the camper to let it down even further. Probably a lot less chance of them rotting out and holding the moisture against the floor.