Side mirror length considerations

[deppstein]

Sorry about misreading 7ft 7 inches for 77". But, that aside, I'm still seeing 7 ft 4 inches (88") MAX across the back. Anyone else?...not that it really matters--just curious.

[Blue~Go]

It's super windy out and I'm being lazy, but it's possible the max width is not right at the rear. Just taking a quick measurement inside near the overhead between the two "narrow bits" in the upper part of the cabinets, I get a wider measurement amidships than I do further forward. So what I'm saying is perhaps the Chinook is slightly "barrel shaped" in the middle vs. right at the taillights if you are looking at it from a bird's eye view. I'm not sure about that -- only guessing at this point.

[chin_k]

The Chinook body is not a perfect box, but have a sexy ( ) swell in the middle. Maybe the difference in the width has to do with exactly where you make the measurement.

I think one of the best solutions for the blind spot is with a rear view camera that is always on when the rig is running. The side mirrors is great for making sure no one is on the side when changing lane, but I think more and more modern car will replace that with a side-camera if DOT and NTSB allow that to replace the optical mirror.

[Blue~Go]

The Chinook body is not a perfect box, but have a sexy ( ) swell in the middle.

I guess "barrel-shaped" wasn't as flattering

[chin_k]

The Chinook body is not a perfect box, but have a sexy ( ) swell in the middle.

I guess "barrel-shaped" wasn't as flattering

I am glad that Trail Wagon did not hire you as their salesman or working for the marketing team.

[deppstein]

OK Chinookers. After all the measurements, discussion, and speculation let's move on to Real Time Testing of the newly installed Velvak 86 inch mirrors...the Envelope Please:

I drove the Rig for a couple of hours on typical residential streets, along a stretch of bustling commercial roadway with parked cars and bike lanes, onto a main 50 mph drag, merged onto a section of The 95 that has 4 lanes running north out of Boston, and then back home via some nice winding 2 lane roads. All in all, I think it was a pretty good test under varying conditions. The weather was clear.

First of all, I definitely noticed a difference in driving through the commercial streets...felt much more confident that I wasn't about to side-swipe a mirror on a parked car, or behead a helmeted biker.

Visibility from the side of the Rig out on either side was just fine...hard to tell the difference between my old mirrors and these new ones once I got used to them being a little closer to me. Using the familiar combination of flat mirror with the wide angel in lower outside corner, I had no trouble on The 95 seeing cars approaching from the adjacent lane, and I had a good perspective of what was going on another lane over as well. Plenty good visibility to safely turn into passing lane, and then also when going back right after passing. As is my usual practice, I generally wait until I can see the car I just passed in the back door window before moving back right.

Moving on to rear visibility--Truth-to-tell, I don't think I have ever paid very close attention to this. I don't tow, and on only a few trips have I been traveling with someone else that wanted to keep track of. That said, I did feel as though the car directly behind me had to be at least 3 car lengths away before I had a chance of catching a glimpse of it in my side mirror. The back door mirror helps some here, but due to its height on the door and view angle, I'd guess that I still don't see a car directly behind me all that well. I do have a back-up camera that I can keep on while driving if I really want to see what is going on back there, but I find the constant vision on the screen (mounted on my doghouse in the ashtray holder) a distraction.

Final verdict--I like the new mirrors and am going to keep them. For me, the upside of not having to worry so much about getting close to something on my right in close quarters, coupled with the continued good side-vision outweighs any loss (slight in my mind) of what is going on directly behind me.

Thanks to all of my deep-diving compatriots and fellow curious Forum buddies for indulging me as I worked through this decision-making process. As I have said before--I love this Forum! Time for another contribution to the Tip Jar...worth every penny.
David

[chin_k]

Dave, you may want to use a traffic cone or a paper box and position it in various places behind your rig to see how well you can see the item. If I have a rear view camera like yours, I feel I will mount the screen somewhere more visible and use it to confirm that there is no lurker right behind your rig on the lane that you are going to move onto. Luckily for me, I usually have my wife with me, and she is pretty good about being the second set of eyes before I move over, but I can't relies on another person all the time.

[deppstein]

Greetings from Pokegon State Park near Angola, Indiana. Beautiful State Park with one campground loop open in winter--with HOT showers, electrical, dump, even a water spigot open for filling if need be. Overnighting here before checking-in with the DutchAire folks tomorrow to get my frig refurbished (I'll report how that goes in another thread soon).
But I'm writing now to post my final evaluation of the new Velvac 86 inch mirrors that I installed a couple of weeks ago. I've been driving with them now for two full days across The 90 from Boston to Indiana. It has been raining a good part of the time, heavy at times, along with some sleet. Roads were wet, but clear. I was essentially "running with the Big Guys the whole way (I'd say that 75% of the traffic on the interstate is Big Rigs). Lots of lane changing, lots of need to be checking my mirrors, both sides--close in, well behind, two and three lanes across. I was even part of a caravan for a good 50 miles, trading headlight/taillight blinking signals back and forth. In short, I felt like this was an excellent test, and I came away very happy with having made the switch. When set properly, I feel like my vision along both sides and out across lanes is as good as it was with my 96 inch mirrors. And, in conjunction with picking up a view of what is behind me through the window of the back door, I had no trouble knowing when to move back into the travel lane after passing, nor was I ever surprised by someone on my tail bursting out to pass. I'm definitely going to keep them. I really do think that with our 91 inch pregnant belly in the middle, and 86.5 inches across the back at mirror height, these are actually the right fit for our Premiers and Concourses. I actually suspect that the 96 inch mirrors that were stock with our vehicles was due to a Ford decision--"put the 96" on the chassis we are selling cuz that's the most common size Rig that will be going onto these chassis."
Don't get me wrong, I'm not here to encourage folks to make a switch...using mirrors is as much an art as it is a science! But I did want to report out that I am very happy with MY decision to swap out.
Cheers
David

[Blue~Go]

I actually suspect that the 96 inch mirrors that were stock with our vehicles was due to a Ford decision--"put the 96" on the chassis we are selling cuz that's the most common size Rig that will be going onto these chassis."

I don't believe Ford had anything to do with the Velvac mirrors. I think as a chassis cab that was left up to Chinook. I don't even think the chassis cabs come with taillights, and I can see where the aft end of the cab on mine just came with some plastic taped across the giant opening.

So I think Chinook, as the completing builder of an incomplete vehicle chose to use Velvacs, the size, and whether a given model got the electric ones, or the heated/electric ones. Same for the rearview mirror, at least in my Chinook (it's not a Ford mirror).

I bet there was some sort of guidance in the BEMM though. I'll probably take a look at that to satisfy my curiosity.

In the meantime, here is a 2013 Ford brochure specifically for the RV/motorhome chassis cab. You can see there are no taillights, the cab has no back, and... no mirrors. This makes sense, as Ford doesn't know specifically what the RV mfgr is going to be putting on the chassis.

Just to add a general note, because I can't look through the whole guide right now. But the general way it works is that for chassis cabs they are sold as an "incomplete vehicle." I think one of the numbers in the VIN shows that. The final builder (Chinook in our case) has to comply with various rules (not sure what they all are but say FMVSS or etc.) Ford also has lots of guidelines.

Anyway, so this is why when you buy an RV (or say a school bus or Ambulance) that has been completeed by an official company, it's usually titled as, say, a Chinook. Or when I had a previous RV and there was a title issue (transposed digit), I had to go the the RV company as it was technically a "1996 Brand X." That said, some states will probably title it as a Ford, but technically it is a Chinook (sold as an incomplete vehicle by Ford). Then it's the RV mfgr's responsibility to build it right (which is what manuals like the BEMM are for; they allow the builder to look up Ford's stipulations for everything from electrical work to frame rail extensions). I'm sure there are plenty of federal guidelines also. No wonder they like to come up with a specific build and stick with it (like our 21-footers).

I did give a cursory look at my copy of the 1998 Ford Incomplete Vehicle Manual (these things are super dense with info for everything from calculating center of mass of the whole rig to driver's seat guidelines) and they do mention that certain incomplete vehicles do come with mirrors from Ford (school buses and some others) and that if they come with mirrors from Ford, then there are rules about changing them and what the completer can and can't do (so I was wrong there and they sometimes come with Ford mirrors). I don't believe Ford supplies Velvacs though, so I'd stil guess that Chinook supplied the Velvacs and sized them according to some guideline (but obviously individuals are free to change them, as we don't have to go by the rules they have to go by in order to be an official builder).

If I manage to plow through far enough to find anything more specific, I'll post back. I will say it's almost quaint compared to reading the same manual for a newer van or truck. Now everything is about CAN bus and "modules" and it's even more complicated.

[deppstein]

Blue…thanks for this morning read. I continue to be amazed at the breadth and depth of your knowledge, and your willingness to research things. I’ve learned a lot from you over the years, and this is yet another example that helps paint a picture for me of how and what our beloved Chinooks are made of.
When I talked to the Velvac tech on the phone and gave him my dimension across the back (I believe it was the 88” across the headlights), he did say the general rule is that anything over 86” gets 96” and anything over 96” gets 102”. So, on both counts—whether Ford supplied mirrors or not, it is now clear to me that 96” were indeed the recommended spec.
But as OMOPP (owner’s matter of personal preference), I’m gonna stick with the shorter 86”….primarily so I don’t have to be constantly worrying about decapitating some poor biker or taking out someone’s fancy side view.
I think it was my grandmother who had a saying about the different choices people make—“To each her own said the lady as she kissed the cow!”