RV.Net Open Roads Forum: Fifth-Wheels: Theoretical heights.

RV Blog

  |  

RV Sales

  |  

Campgrounds

  |  

RV Parks

  |  

RV Club

  |  

RV Buyers Guide

  |  

Roadside Assistance

  |  

Extended Service Plan

  |  

RV Travel Assistance

  |  

RV Credit Card

  |  

RV Loans

Open Roads Forum Already a member? Login here.   If not, Register Today!  |  Help

Newest  |  Active  |  Popular  |  RVing FAQ Forum Rules  |  Forum Posting Help and Support  |  Contact  

Search:   Advanced Search

Search only in Fifth-Wheels

Open Roads Forum  >  Fifth-Wheels

 > Theoretical heights.

Reply to Topic  |  Subscribe  |  Print Topic  |  Post New Topic  | 
Page of 4  
Next
Sponsored By:
MatthewThomas

FL

New Member

Joined: 05/11/2022

View Profile



Posted: 05/11/22 04:36pm Link  |  Quote  |  Print  |  Notify Moderator

I was looking up the legal DOT heights (13.5ft) as well as the minimum recommended clearance between truck and bottom of the 5th wheel overhang (6in) then crossed it with the most recent height measurements for Ford trucks (no bias, just the first one I could find).

They don't have a direct measurement to the top of the bed but they had a measurement from open tailgate to ground 36.9in (F350 biggest wheelbase) then a height from the bottom of the bed to the top 21.1in, totaling 58in.

Adding the 6in for bed clearance - 64in.

Now take the federal max height 13.5ft (162in), and minus 2in (personal choice for peace of mind) which leaves 160in.

Minus the 64in and that leaves you with 96in or 8ft.

My question is, if you take off an extra foot for insulation and structuring (would be a bit excessive but using it for a more conservative outlook), could the interior of the overhang portion of the 5th wheel be 7ft?

Cptnvideo

Arizona - most of the time

Senior Member

Joined: 11/05/2006

View Profile


Offline
Posted: 05/11/22 04:46pm Link  |  Quote  |  Print  |  Notify Moderator

Good question. But why 7 ft for the bedroom (in most 5th wheels)?
I just measured our floor to ceiling in our 2022 Grand Design Solitude 378 MBS bedroom and it is 6.5 ft (78").


Bill & Linda
Arizona
2019 Dodge Ram Laramie 3500 dually 4x4 diesel
Hensley Trailer Saver BD5 hitch
2022 Grand Design Solitude 378MBS
1600 watts solar, Victron 150/100 MPPT controller, GoPower 3kw inverter/charger, 5 SOK 206AH LiFePo4 batteries for 1030 ah

Veebyes

Bermuda & Maryland Eastern Shore

Senior Member

Joined: 11/24/2003

View Profile


Offline
Posted: 05/11/22 07:17pm Link  |  Quote  |  Print  |  Notify Moderator

I am thoroughly confused. If you want to know your air draft simply measure from your highest point to the ground while hooked up.

How difficult is that?


Boat: 32' 1996 Albin 32+2, single Cummins 315hp
40+ night per year overnighter

2007 Alpenlite 34RLR
2006 Chevy 3500 LT, CC,LB 6.6L Diesel

Ham Radio: VP9KL, IRLP node 7995

MatthewThomas

FL

New Member

Joined: 05/11/2022

View Profile



Posted: 05/11/22 07:46pm Link  |  Quote  |  Print  |  Notify Moderator

Veebyes wrote:

I am thoroughly confused. If you want to know your air draft simply measure from your highest point to the ground while hooked up.

How difficult is that?



Unnecessary, but this is theoretical, I don't have a unit, but am planning a build and want to know if my theoretical numbers make sense.

MatthewThomas

FL

New Member

Joined: 05/11/2022

View Profile



Posted: 05/11/22 07:57pm Link  |  Quote  |  Print  |  Notify Moderator

Cptnvideo wrote:

Good question. But why 7 ft for the bedroom (in most 5th wheels)?
I just measured our floor to ceiling in our 2022 Grand Design Solitude 378 MBS bedroom and it is 6.5 ft (78").



I figured there is about 6ft or so for the overhang, which would make the dimensions of that space, 8'w by 6'd by 7'h. So a decent room.

Plus I'm 6ft2in so though 6ft6in isn't too bad, it's right above my head haha.

Cptnvideo

Arizona - most of the time

Senior Member

Joined: 11/05/2006

View Profile


Offline
Posted: 05/11/22 08:05pm Link  |  Quote  |  Print  |  Notify Moderator

4" above your head sounds fine for a room that is only used for sleeping and getting dressed.

MNRon

Tennessee

Senior Member

Joined: 08/18/2007

View Profile



Good Sam RV Club Member

Offline
Posted: 05/12/22 06:47am Link  |  Quote  |  Print  |  Notify Moderator

There's usually an AC on top of that roof that you haven't accounted for


Ron & Pat
2022 F350 Lariat CCSB SRW Diesel
2019 VanLeigh Vilano 320 GK

way2roll

Wilmington NC

Senior Member

Joined: 10/05/2018

View Profile


Offline
Posted: 05/12/22 07:54am Link  |  Quote  |  Print  |  Notify Moderator

I am also confused. Are you building a FW from the ground up? I am sure specs/dimensions are readily available for most production units. Why live in theory, go to an RV dealer and take measurements.


2023 FR Sunseeker 2400B MBS

ACZL

UPstate,NY

Senior Member

Joined: 10/09/2001

View Profile



Good Sam RV Club Member

Offline
Posted: 05/12/22 09:04am Link  |  Quote  |  Print  |  Notify Moderator

My '17 F350 DRW 4x4, CC w/ 8' box and '18 Big Country comes in at 13'4" last time I measured it. The national bridge height is 13'6" not 13'5". BUT there is a built in add'l foot on MOST bridge clearance heights. We still have 6" of clearance from top of box to underside of 5er. One thing you have to take into consideration (unless you have airbags) is that the rear of the truck will squat down w/ 5er on so this brings down the top front height of your 5er. RV transporters don't have problems and they have all kinds of truck configurations. Just sayin'.


2017 F350 DRW XLT, CC, 4x4, 6.7
2018 Big Country 3560 SS
"The best part of RVing and Snowmobiling is spending time with family and friends"
"Catin' in the Winter"

Cummins12V98

on the road

Senior Member

Joined: 06/03/2012

View Profile


Offline
Posted: 05/12/22 09:51am Link  |  Quote  |  Print  |  Notify Moderator

I am 13' 4" at highest point, my top of tailgate is 55" loaded or not and have 6" bed clearance. Never heard of anyone being higher.


2015 RAM LongHorn 3500 Dually CrewCab 4X4 CUMMINS/AISIN RearAir 385HP/865TQ 4:10's
37,800# GCVWR "Towing Beast"

"HeavyWeight" B&W RVK3600

2016 MobileSuites 39TKSB3 highly "Elited" In the stable

2007.5 Mobile Suites 36 SB3 29,000# Combined SOLD

Reply to Topic  |  Subscribe  |  Print Topic  |  Post New Topic  | 
Page of 4  
Next

Open Roads Forum  >  Fifth-Wheels

 > Theoretical heights.
Search:   Advanced Search

Search only in Fifth-Wheels


New posts No new posts
Closed, new posts Closed, no new posts
Moved, new posts Moved, no new posts

Adjust text size:




© 2023 CWI, Inc. © 2023 Good Sam Enterprises, LLC. All Rights Reserved.