2013+ Ford Escape Forum banner

41 - 57 of 57 Posts

·
Registered
Joined
·
57 Posts
Maybe Ford should delete the roof rails on any Escape equipped with the sunroof. That would eliminate any confusion.
It’s already that way (at least on the ford site in USA).
If you select a package that has a moonroof, then try to select the cross bars, it tells you that you can either keep the moonroof or remove the moonroof to add the cross bars.
If you add the cross bars first, and try to add the moonroof package, the same thing occurs.

if you mean getting rid of the mounting rails on some models, I think that would probably be a bigger engineering issue (and cost, now you’re making even more parts) but I’m not an engineer. It’s also possible they’re working on a future solution, that happens a lot with a full redesign.
 

·
Registered
Joined
·
84 Posts
It’s already that way (at least on the ford site in USA).
If you select a package that has a moonroof, then try to select the cross bars, it tells you that you can either keep the moonroof or remove the moonroof to add the cross bars.
If you add the cross bars first, and try to add the moonroof package, the same thing occurs.

if you mean getting rid of the mounting rails on some models, I think that would probably be a bigger engineering issue (and cost, now you’re making even more parts) but I’m not an engineer. It’s also possible they’re working on a future solution, that happens a lot with a full redesign.
I understand you can't get the cross rails with a moon roof. My question is why Ford even puts on the side rails if you order a moon roof. They are saying 0 lbs. load on the roof so they are not needed.
 

·
Registered
Joined
·
86 Posts
Watch a video on car production, specifically paint. One reason you can't beat factory paint is use of immersion application. Most cars in the post drip-rail era have a channel where the side rails are located. That's where they hold the body while painting. It makes sense all cars cover this area the same way, because there's something else going on that's not in the least bit obvious.

The roof rails are part of the car's aerodynamic stability system.

It's a truism that very low drag vehicles are unstable in crosswind. As speed increases, the center of pressure (where drag force acts) moves forward. The car is stable as long as the center of pressure is behind the center of mass. There's a straightening force pulling from behind, like feathers on an arrow. The arrow has less drag without feathers, but won't fly straight. This is why all Porsche 911-based cars have a speed-sensitive rear spoiler of some sort. Race cars have rear wings to create drag at the rear in crosswind. You don't see wings on passenger cars.

Modern SUV's all have similar profiles because aerodynamics is a harsh master; there are few low-drag options. They also share certain features, as a result. One neat way to deal with crosswind issues is to "spoil" the aerodynamics when airflow is angled (crosswind at speed). The goal is to minimize Cd when passing through still air (airflow due only to vehicle motion) while ensuring that Cd rises if air has to cross the car's centerline. Higher Cd pushes the center of pressure to the rear regardless where the increase comes from.

So, look at the car, and notice there's a raised section around the windshield that extends up to the roof rails. Air flows smoothly along the length, but turbulently across these features. Turbulent flow increases drag so the car stays pointed where you're steering.

Stay well,
Frank

Ref.: Hucho, Wolf-Heinrich, Aerodynamics of Road Vehicles, 1987
 

·
Registered
Joined
·
216 Posts
I understand you can't get the cross rails with a moon roof. My question is why Ford even puts on the side rails if you order a moon roof. They are saying 0 lbs. load on the roof so they are not needed.
Where did you get 0 lbs with a moonroof?
Pretty sure my 2019 is 50lbs with a moonroof, 100lbs without...

Sent from my SM-G965W using Tapatalk
 

·
Registered
Joined
·
359 Posts
Watch a video on car production, specifically paint. One reason you can't beat factory paint is use of immersion application. Most cars in the post drip-rail era have a channel where the side rails are located. That's where they hold the body while painting. It makes sense all cars cover this area the same way, because there's something else going on that's not in the least bit obvious.

The roof rails are part of the car's aerodynamic stability system.

It's a truism that very low drag vehicles are unstable in crosswind. As speed increases, the center of pressure (where drag force acts) moves forward. The car is stable as long as the center of pressure is behind the center of mass. There's a straightening force pulling from behind, like feathers on an arrow. The arrow has less drag without feathers, but won't fly straight. This is why all Porsche 911-based cars have a speed-sensitive rear spoiler of some sort. Race cars have rear wings to create drag at the rear in crosswind. You don't see wings on passenger cars.

Modern SUV's all have similar profiles because aerodynamics is a harsh master; there are few low-drag options. They also share certain features, as a result. One neat way to deal with crosswind issues is to "spoil" the aerodynamics when airflow is angled (crosswind at speed). The goal is to minimize Cd when passing through still air (airflow due only to vehicle motion) while ensuring that Cd rises if air has to cross the car's centerline. Higher Cd pushes the center of pressure to the rear regardless where the increase comes from.

So, look at the car, and notice there's a raised section around the windshield that extends up to the roof rails. Air flows smoothly along the length, but turbulently across these features. Turbulent flow increases drag so the car stays pointed where you're steering.

Stay well,
Frank

Ref.: Hucho, Wolf-Heinrich, Aerodynamics of Road Vehicles, 1987
Good theory, but I can't agree... Unless I am missing something in your long explanation. (I AM NOT AN ENGINEER, however) Oh! and I noticed you are quoting a reference from 1987???

My '19 Acura RDX is a crossover, and DOES NOT have side rails. I find no difference driving it in crosswinds compared to our recently departed '15 Escape which DID have side rails.
 

·
Registered
Joined
·
86 Posts
My '19 Acura ...
Honda has very competent engineers. There are typically many solutions to complex tasks such as car design. It should surprise no one if companies do things differently.

Some laws don't change. Air flows the same way today as in 1987, but modeling of airflow has advanced tremendously with computer capability. Modern analysis is more detailed, but based on the same physical relationships.

Stay well,
Frank
 

·
Registered
Joined
·
216 Posts
So long as whatever you clamp to the crossbar isn't over the glass!
 

·
Registered
Joined
·
216 Posts
Lots of noise on my 2019
Ugh!
 

·
Super Moderator
Joined
·
2,224 Posts

·
Super Moderator
Joined
·
2,224 Posts
Lots of noise on my 2019
Ugh!
😢 Only have them on when you need to use them. You could try sealing any gaps on the underside of the cross bars with duct tape.
 

·
Registered
Joined
·
216 Posts
Only have them on when you need to use them. You could try sealing any gaps on the underside of the cross bars with duct tape.
Yeah, they're easy enough to remove. And the front bar has a "parking spot" in the back so the noise isn't so bad for the driver.
 

·
Registered
2020 2.0 AWD Titanium
Joined
·
5 Posts
So long as whatever you clamp to the crossbar isn't over the glass!
The Thule rails have a T track in the top so nothing will extend below the rail. I still would avoid opening the glass with a my kayak on the roof. but its nice to know if I do accidentally open the glass it will clear.
I didn't get any pictures but I did put my kayak mounts up and set the kayak on to see if there was enough flex to make the rails contact the glass but everything still cleared. although its still possible they could flex more while driving down the road with bumps and wind shaking everything.
 
41 - 57 of 57 Posts
Top