Traversing difficult terrain with a roof top tent

DaveInDenver

Expedition Leader
#16
Whether you think you feel the added weight up high or not, there's no question it does make your truck more tippy. I personally even hate the feeling of jerry cans on the roof. But consider that you will butt clinch before the truck is actually in a situation where your COG matters. In @kdeleon's photo you can see he's getting close, though.
 

DaveInDenver

Expedition Leader
#17
Just a couple of videos to consider. The first one I think demonstrates that (1) you fight the instinct to grab a truck (and take the time to learn to drive & spot) and (b) that trucks are more stable than you think...


... until they aren't.

 

MattJ

Adventurer
#18
Does anyone have experience with a clinometer app that they want to share? I've always wondered how easy they are to install (presumably a Bluetooth link with the OBD port) and how accurate they are (that is, can they really help pinpoint when a situation is uncomfortable but safe versus uncomfortable and very dangerous).
 

MattJ

Adventurer
#19
Just a couple of videos to consider. The first one I think demonstrates that (1) you fight the instinct to grab a truck (and take the time to learn to drive & spot) and (b) that trucks are more stable than you think...
... until they aren't.
Thanks for sharing those. The first one . . . well, no comment. I'm sure it's all been said in the YouTube comments.

On the second one, it looks like there was plenty of room to get the front end pointed down the slope a bit more (driver side) since the trail was nice and wide, but maybe there may be other reasons why the driver had to stay off-camber. You can certainly see that the flop was triggered by the front end coming down off an obstacle or into a depression very suddenly. That's why the off-camber stuff is so intense - it really makes choosing a line much more challenging and risky.
 
#20
Thanks for sharing those. The first one . . . well, no comment. I'm sure it's all been said in the YouTube comments.

On the second one, it looks like there was plenty of room to get the front end pointed down the slope a bit more (driver side) since the trail was nice and wide, but maybe there may be other reasons why the driver had to stay off-camber. You can certainly see that the flop was triggered by the front end coming down off an obstacle or into a depression very suddenly. That's why the off-camber stuff is so intense - it really makes choosing a line much more challenging and risky.
The second vid is on Black Bear pass. I was there a week after this video so that makes me an expert :D. Yes you do have to point the truck to the left to combat the off-camber situation. The problem is, not shown in this video, is that you'll be facing your truck to a drop to the edge . You have a small patch where you will be dropping off your left front, and once you're planted at the bottom then you can start straightening back to the track. I think this is enough to make folks take a straighter line as it looks "safer". Couple that with a natural reaction to hit the brakes and you got a reciper for a rollover. This truck in the vid didn't seem to have much front flex at all so i think that compounded the situation.
 

DaveInDenver

Expedition Leader
#21
Regards the Black Bear video. Correct me if I'm wrong, @kdeleon, since it sounds like you may have been there (I believe it was the FJ Summit this year). Didn't a couple of similarly built FJ Cruisers go before him? I don't know all the details and I don't know that weight on the roof was even a factor. He just looked to me even just creeping up he was already getting light in the right rear.

Generally it's better *not* to have a roof rack and if you do having a lot of weight up high is the worst place, compounded if you put a large amount of your cargo up there to make interior space that might otherwise help keep COG lower. IOW, empty truck + RTT = significantly reduced tip angle.

The two videos do highlight the difference in calm, controlled 'wheeling vs. impulsiveness. He flopped but it was more about soiled shorts than being dangerous yahoos.
 
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MattJ

Adventurer
#22
The fella with the camera in the foreground also caught my eye, since it takes a full three seconds for him to react to the flop. Presumably he was filming the whole thing and wanted to make sure he got a steady shot of the entire thing?

I am VERY careful about making sure everything inside the vehicle is strapped down very well. In fact, I use a triple-layer of protection with the cargo area: a bungie net, then criss-crossing ratchet straps, then some dog-barrier nylon webbing between the cargo area and passenger seats.

Next question: in some training classes, I was instructed to always keep both hands on the wheel when off-camber. But in my trail experiences, it feels like that technique forces me to hold myself upright using the wheel to brace me. I worry that I will pull the steering wheel off line as a result or have less control with slow and delicate maneuvers. So instead, I keep one hand on the wheel, unweighted, with a firm grip and steady control. With the other hand I use a grab bar or the lip of that compartment on top of the JKU dashboard to steady myself. Any opinions on this topic? I know there are a lot of natural but dangerous tendencies that us humans have when tipping over, so I wanted to check this one.
 
#23
Regards the Black Bear video. Correct me if I'm wrong, @kdeleon, since it sounds like you may have been there (I believe it was the FJ Summit this year). Didn't a couple of similarly built FJ Cruisers go before him? I don't know all the details and I don't know that weight on the roof was even a factor. Generally it's better *not* to have a roof rack and if you do having a lot of weight up high is the worst place, compounded if you put a large amount of your cargo up there to make interior space that might otherwise help keep COG lower. IOW, empty truck + RTT = significantly reduced tip angle.
I wasn't in FJ Summit, i was there a week or so after where I had Black Bear to myself (for better or for worse!). That vid looks more like just a matter of abrupt weight transfer (look at the brake lights). And the lack of flex warranted a better line selection, things you can get away with say a jeep wrangler (taking the video). Brakes are probably the #1 cause of rollovers :)

It does totally make sense, empty truck and RTT reduces tip angle. That is my excuse for overloading my truck! I am going back to CO next year without the family so guess what i am not taking next year!
 

DaveInDenver

Expedition Leader
#24
Next question: in some training classes, I was instructed to always keep both hands on the wheel when off-camber. But in my trail experiences, it feels like that technique forces me to hold myself upright using the wheel to brace me. I worry that I will pull the steering wheel off line as a result or have less control with slow and delicate maneuvers. So instead, I keep one hand on the wheel, unweighted, with a firm grip and steady control. With the other hand I use a grab bar or the lip of that compartment on top of the JKU dashboard to steady myself. Any opinions on this topic? I know there are a lot of natural but dangerous tendencies that us humans have when tipping over, so I wanted to check this one.
You want both hands on the wheel all the time. First is so you always have a firm hold if the wheel jerks but also because in the the case of a flop or roll you want to avoid your arms getting flung out of the window and broken or crushed. Like they say at the amusement park, always keep hands and feet inside the vehicle. Also I was taught to keep your thumbs on the outside because if you do roll or the wheel gets spun you don't want to break 'em.

Personally I also find a firm grip and staying upright and neutral in the seat prevents your head and upper body from naturally tilting so you get a more true sense of your angle. You will naturally lean uphill to keep the horizon flat but your truck is leaning more than you perceive. Same thing happens on the highway, which can lead IMO to turning too sharp with flexy suspension or pushing too hard on wet or snowy pavement. I try to stay in the middle of my seat with my head upright relative to my shoulders and torso.
 

MattJ

Adventurer
#25
You want both hands on the wheel all the time. Also I was taught to keep your thumbs on the outside because if you do roll or the wheel gets spun you don't want to break 'em. Personally I also find a firm grip and staying upright and neutral in the seat prevents your head and upper body from naturally tilting so you get a more true sense of your angle.
Yeah - that's what I was taught. Both hands on wheel, thumbs outside, stay neutral to the seat, not the ground. But in that position it really feels much harder to steer with as much control since the wheel is holding more of my bodyweight (even though it shouldn't be). I guess I need some more practice!
 
#26
Yeah - that's what I was taught. Both hands on wheel, thumbs outside, stay neutral to the seat, not the ground. But in that position it really feels much harder to steer with as much control since the wheel is holding more of my bodyweight (even though it shouldn't be). I guess I need some more practice!
They didn't mention they do that while driving with 6-point harness :).

I personally use the grab bar to push myself into the seat when needed, so i can put a light touch on the steering wheel. Never do i hold myself up with the steering wheel.

Oh you can also lock your seatbelt, it is not as effective as a 6-point but better than holding your body with steering wheel.
 

DaveInDenver

Expedition Leader
#27
It's true that it's probably not natural unless you're a pro driver, which I guess is what they do naturally which makes them predisposed to being good at it. They feel (so to speak) the car better than the rest of us.
 
#28
Does anyone have experience with a clinometer app that they want to share? I've always wondered how easy they are to install (presumably a Bluetooth link with the OBD port) and how accurate they are (that is, can they really help pinpoint when a situation is uncomfortable but safe versus uncomfortable and very dangerous).
Honestly, I have an inclinometer on my dash and an app. I have never used them while in a situation. If you are paying attention to the meter then you are not paying attention to your driving. It has made for fun conversations after the obstacle if you had a passenger looking at it. I have been in the spot referenced in this thread on Black Bear and it is very deceiving. I have a RTT and have always felt the pucker factor long before the vehicle was in danger.

Sent from my SM-G935P using Tapatalk
 

80t0ylc

Hill & Gully Rider
#29
Does anyone have experience with a clinometer app that they want to share? I've always wondered how easy they are to install (presumably a Bluetooth link with the OBD port) and how accurate they are (that is, can they really help pinpoint when a situation is uncomfortable but safe versus uncomfortable and very dangerous).
Inclinometers are bling for passengers. As someone said already, if you're watching it - you're not watching the trail. Reactions are everything and they have to be quick, decisive and correct. In these 2 videos, 2 very different situations, but both had inexperienced drivers - well, no one really wants to experience a rollover with their rig. In the 1st video, (which by the way is a bad example for this thread, because the rig did not have a RTT. Anyway,) the rookie spotter needed to tell the driver, once he lost momentum and couldn't continue uphill, to crank his wheels hard left to get the rig in a straight uphill posture as he was backing up. You could barely tell from the camera angle, but the path had a slight sidehill bias to it. Not an easy climb and worse for top heavy (read RTT equipped) vehicles. Biggest rule on climbing or descending is straight up or down and keep that posture as much as possible. If you are coming off of moving sidehill, choose downhill. Reason being that you want the natural tendancy of cornering forces to work for you and not against you. IF you turn uphill, the cornering force will be aided by gravity to cause you to roll the rig. So if you MUST go uphill from a sidehill posture, slow your rig to walking speed or less, before turning. In the 2nd video, the angle and distance makes it difficult to analyse. Driver's track looked like, a poor choice because he had downhill wheels (driver's or left side)in a slight depression or erosion channel which made it more of a sidehill bias than necessary. Almost looks like driver's side front wheel either hit an obstacle or dropped into a pothole because you could see the rig stop and the rear end shift to the left (downhill) as it rolled over and driver was probably hard on the brakes. Good that he was crawling and just went on his side, because I bet that hill was steeper than it looked in the video.
 
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