Brad NSW Posted April 19, 2018 Report Share Posted April 19, 2018 Designing deck plan and wondered what you used for Smart car width? From the attached picture, if you fold mirrors in, it looks like you can use 62"' instead of 69". Did you also use 48" from center of 5th wheel pin or did you give yourself 3-4" more (51-52") for flex in uneven terrain? Right now I'm using 69" for Smart and 52" clearance from 5th wheel but this makes the depth of my Drom pretty narrow. I'm thinking of: 1. Going to 48" clearance to pin (how many times do you ever jackknife the rig). 2. Using 65 for Smart width. Thought/feedback/insights from your experiences? Thanks in advance! Link to comment Share on other sites More sharing options...
DesertMiner Posted April 19, 2018 Report Share Posted April 19, 2018 I bet if you search around you will find your answers. I believe the "wiser" folks are using something in the 60" range for the clearance to the pin. Check with your buds on the FB page. They always have a lot to say on the subject. Link to comment Share on other sites More sharing options...
GlennWest Posted April 19, 2018 Report Share Posted April 19, 2018 Be careful getting it too close. Those tough places, think 90 degrees, your mind is not on Smart. opps!!!!! Link to comment Share on other sites More sharing options...
NoDirectionHome Posted April 19, 2018 Report Share Posted April 19, 2018 "Consider a steep uphill where the front cap on the fifth wheel tilts towards the Smart. You should do a proper layout. You basically need the width of the Smart + the 51" width of the trailer at 90 degrees to the truck + the minimum clearance you dare to use considering the above. (I used 10 inches) Link to comment Share on other sites More sharing options...
lockmup68 Posted April 19, 2018 Report Share Posted April 19, 2018 and if you mount bikes to the front of the 5ver! don't forget about the bikes. Link to comment Share on other sites More sharing options...
Brad NSW Posted April 19, 2018 Author Report Share Posted April 19, 2018 Taking it out this weekend to the desert. If I put the truck in a series of decreasing turns till I hit 90 degrees, and drop a plumb line to the deck from the corner of the 5er nose each time. That would mark the "flat ground" arc of the nose on the deck. From there I'd add a safety margin. NoDirectionHome, sounds like you use 10" for this margin. QUESTION: Anyone use or recommend anything else (+ or -)?? For you who have done this for years, is jack-knifing (with the smart car still on) something you've ever had to do? Never came close in 8 years with a 1-ton but I've got no experience with these big boys! Bikes ride inside 5er, Lockmup but great point! I know some who have them on the hitch. Link to comment Share on other sites More sharing options...
rickeieio Posted April 19, 2018 Report Share Posted April 19, 2018 Do yourself a favor and take a measurement with the rig at 45 degrees. You might be in for a surprise. It's all been discussed here in the past year. Link to comment Share on other sites More sharing options...
GlennWest Posted April 19, 2018 Report Share Posted April 19, 2018 Half the width of camper is where it goes. Link to comment Share on other sites More sharing options...
HERO Maker Posted April 19, 2018 Report Share Posted April 19, 2018 57 minutes ago, GlennWest said: Half the width of camper is where it goes. Plus a margin for tilt. I am 127" off of my drom box. I feel I can stay there even with the 16-17 model. But a few more inches wouldn't hurt! Plan for that real strange situation now so you won't have to be wishing you had planned for it when it actually happens. Link to comment Share on other sites More sharing options...
PaHunter Posted April 19, 2018 Report Share Posted April 19, 2018 Going to ECR this year one exit from a truck stop was a steep hill down to the roadway, I am sure the trailer got a lot closer to my cab than I care for. Of course this trip was just with our one ton and not a HDT. Link to comment Share on other sites More sharing options...
rickeieio Posted April 19, 2018 Report Share Posted April 19, 2018 2 hours ago, rickeieio said: Do yourself a favor and take a measurement with the rig at 45 degrees. You might be in for a surprise. It's all been discussed here in the past year. I give up. I've been trying to find the drawing Henry posted showing the arc of the front cap of a fiver during a turn. Some times the closest point isn't at 90 degrees. Link to comment Share on other sites More sharing options...
dennisvr Posted April 20, 2018 Report Share Posted April 20, 2018 I believe closes would be at 45 degrees (front corner of trailer to center of truck), then after 90 degrees it would get close to the side of the trailer. I also would think it would have to do with your pin box. One straight down would give you less room. Link to comment Share on other sites More sharing options...
Brad NSW Posted April 20, 2018 Author Report Share Posted April 20, 2018 Glenn and HeroMaker, that is my thinking. 1/2 width of trailer (me 48") + safety margin makes sense to me. What do people use for the safety margin? NoDIrectionHome uses 10". I was thinking less. Here is how my extended pin box would swing. I'll confirm this out in the desert this weekend. It extends the pin to the front edge of the 5th wheel (and the 5er has a bit of curvature, not the box shown below), So, it appears the closest point of approach is 90 degrees. Up until 70 degrees there is a BIG margin. How many people have had to jack-knife their rigs? Link to comment Share on other sites More sharing options...
Jack Mayer Posted April 20, 2018 Report Share Posted April 20, 2018 We use about 151" from back of cab to pin location. That leaves 18" for drom (16" drom and 2" to BOC). That is more than enough, and accounts for different types of pinboxes and caps. Link to comment Share on other sites More sharing options...
noteven Posted April 20, 2018 Report Share Posted April 20, 2018 It’s the long side of a right angle triangle unless the king pin is right in line with the front of every trailer you will ever hook up to, then it is 1/2 the trailer width. Take a stick and saw it off at the distance from the center of the king pin to the widest point at the front of the trailer plus 6”. Then use the stick as a story stick as you look at the layout you want at the back of the truck. Now from the end of your stick look up at 90 degrees. That line needs a minimum of 8” of dip clearance to anything on the deck of the truck. Link to comment Share on other sites More sharing options...
Brad NSW Posted April 23, 2018 Author Report Share Posted April 23, 2018 Jack - thanks, that 151" number is helpful! I've got that to play with. NotEVen - I like your stick concept. Basically did that out in the desert this weekend by jackknifing the truck and then plotting the arc of the longest leg of that triangle you reference at 5 degree intervals. With the extended pin box nothing crossed a line 48" from the pin box until I hit 90 degrees, so that's encouraging. I'm thinking this is all going to come together and I'll be able to squeeze a drom and the Smart on the deck and have a safety margin for those tight turns over a dip in the road. Link to comment Share on other sites More sharing options...
noteven Posted April 23, 2018 Report Share Posted April 23, 2018 Brad - yer Freightliner should not be able to "out turn" the trailer in your signature image in "go forward". It is amazing how fast your rig folds in half when you are wiggling backwards into some spot with 3 people waving their arms and hollering at you which way to "turn yer wheels" Link to comment Share on other sites More sharing options...
HERO Maker Posted April 23, 2018 Report Share Posted April 23, 2018 Brad, also remember, the width of your current trailer, may not be the width of your future one! Link to comment Share on other sites More sharing options...
Brad NSW Posted April 24, 2018 Author Report Share Posted April 24, 2018 NotEven and HEROMaker - both great points. I agree "going fwd" shouldn't ever be a problem. I would anticipate anytime I'm trying to get into a tight spot and all the onlookers giving direction I would have already unloaded the Smart car...then no clearance problems. Not looking to upgrade trailers anytime soon but that's definitely a good point. E-mailed comfort ride hitch and asked them if I could move the hitch back and secure it with only 6 bolts instead of the current 8 on each side. That would give me an extra 7 inches too. Link to comment Share on other sites More sharing options...
GlennWest Posted April 24, 2018 Report Share Posted April 24, 2018 Always I use size larger bolt if I use less than called for Link to comment Share on other sites More sharing options...
Brad & Jacolyn Posted April 25, 2018 Report Share Posted April 25, 2018 I have 150" from the back of the cab to the center of the hitch head. I have no drom so I have lots of room. Brad Link to comment Share on other sites More sharing options...
GlennWest Posted April 25, 2018 Report Share Posted April 25, 2018 Mine is 150" also. No problems. I don't have a drom but I do have the fairings. Link to comment Share on other sites More sharing options...
HERO Maker Posted April 26, 2018 Report Share Posted April 26, 2018 You do need to consider the fairings because the car won't fit between them. Not sure what the depth is. Probably something like 12 inches. Someone will tell us. Link to comment Share on other sites More sharing options...
GlennWest Posted April 26, 2018 Report Share Posted April 26, 2018 150-151 from back of cab will work even with fairings. Without fairings it could be less but loose the drom box option Link to comment Share on other sites More sharing options...
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