Rivian off-road struggling?

[CommodoreAmiga]

Nothing I saw in this video makes me believe the R1T software needed tweaking to perform well on this trail. The driver simply didn’t have the experience to know what to do. Most likely, the R1T “struggled” due to pilot error.

I think it just requires a different mentality than experienced ICE offroaders have developed. Wheel spin is "bad", right? Or at least that's traditional thinking. But the R1T needs that wheel spin so the computers can see the loss in traction and increase motor output on the opposite side. At least, that's my understanding of the current state.

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[Zybane]

Show me the rocks you're talking about that will get cleared by 37"s on 18"s that the R1T won't clear on 34"s on 20"s. I don't believe there are any. I've yet to run into a rock that I couldn't get my Defender over, and it's not on steelies, so basically the tire combo equivalent of the R1T.

Basically any of the obstacles on the Rubicon trail. I'd pay to see a Rivian do the trail. If not anything, to see what its real capabilities are.

I have not seen a video of the Rivian doing any difficult trails. The closest was Hells Gate in MOAB, which actually isn't that difficult (solid rock with a lot of traction).

BTW a 34" tire on a 20" rim doesn't leave a whole lot of tire side-wall left when you air down. For those that aren't into off-roading.

 

[Inkedsphynx]

Basically any of the obstacles on the Rubicon trail. I'd pay to see a Rivian do the trail. If not anything, to see what its real capabilities are.

I have not seen a video of the Rivian doing any difficult trails. The closest was Hells Gate in MOAB, which actually isn't that difficult (solid rock with a lot of traction).

BTW a 34" tire on a 20" rim doesn't leave a whole lot of tire side-wall left when you air down. For those that aren't into off-roading.

Buddy of mine did Rubicon last summer in a Taco on 34"s. He was on 18" rims, but that little extra bit of sidewall isn't the literal difference between "can do" and "can't do". In no world is his Taco more capable than the R1T will be.

Like I said, I've got no concerns. I'm sure yours will be alleviated as well once you can take it out and see for yourself.

 

[kylealden]

The Rivian cooling fans kicked into high on that obstacle. A day with everyone in multi layers of jackets with some snow still on the ground.

This isn't meaningful data. My Tesla's cooling fans kick into high all the time for no apparent reason, including while parked on a cool day. Sometimes it's climate use, sometimes it's managing pack temp after a charge or a long drive (or even just my short and very low-key commute home), sometimes it's presumably just moody. We can't extrapolate that to motor current, especially not in realtime and second-hand through a YouTube video.

Meanwhile the driver said he was babying it.

It's clear that the Rivian won't compete with a built rock crawler at its peak mechanical advantage. To me that's the right set of tradeoffs. It's a bone stock electric truck that gets 70 eMPG. It has a luxury interior. But it's still premature to jump to the conclusion that it is underpowered and needs lockers. We have lots of evidence to the contrary and one video that is barely an anecdote to say otherwise.

 

[Zybane]

Buddy of mine did Rubicon last summer in a Taco on 34"s. He was on 18" rims, but that little extra bit of sidewall isn't the literal difference between "can do" and "can't do". In no world is his Taco more capable than the R1T will be.

Like I said, I've got no concerns. I'm sure yours will be alleviated as well once you can take it out and see for yourself.

Well we have all heard the stories of the guy with the Honda Accord doing the Rubicon trail lol. And of course there are a lot of obstacle bypasses you can take and still say you did the trail.

 

[cardad]

You sure you had the front differential locked up? It's a mechanical locking diff, it's impossible for the two front wheels to spin at different speeds when it's locked in the tri-motor Hummer EV. Brakes aren't needed at all.

https://www.aam.com/media/story/aam-s-tracrite-differentials-help-new-gmc-hummer-ev-conquer-the-road#:~:text=The GMC HUMMER EV features,turn at the same speed.

Speed/throttle is the nemesis to a lot of rock crawling. So much in fact that a good driver in an ICE vehicle two-foots over rocks, presses down on the brake pedal with their left foot to create drag and slow throttle modulation to overcome the brake friction and slowly roll over rocks as to not jerk the truck and driveline.

This is possible with something like a Jeep Rubicon that has way, way more mechanical advantage than say the Rivian. In my calculations, a Jeep Rubicon has over 31K of effective ft/lb of torque that can be applies to all four wheels simultaneous in the Diesel.

Richard Farquhar - Vice President of Propulsion - Rivian:

"
Charged: You said that there are symmetrical drive units, so you have four identical sets of motors and drives?


Richard Farquhar: That’s correct – we have four identical motors, left and right, front and rear. Every wheel has the exact same amount of torque and power available to it to maximize performance. We achieve over 14,000 Newton-meters of grounded torque at the wheels combined and 125 miles per hour maximum speed. With the fixed-ratio single-speed gearbox there is no need to change gears, no need for twin speeds. This maximizes efficiency in terms of losses from gear meshing while achieving all of our performance targets. "

14,000 nM is 10,325 ft/lb. That's 2,581 per wheel. Compared to a Jeep Rubicon which can do over 31,000 per wheel.

The mechanical advantage of something like a Diesel Rubicon that has its Engine Torque multiplied by the fluid Torque Converter multiplied by transmissions 1st gear, multiplied by the transfer case, multiplied by the differentials, gives insane torque figures at the wheels. Far far higher than Rivians small motors can accomplish.

But Rivian is more worried about efficiency than climbing over rocks. Rivian motors are actually quite small and aren't geared to put down a ton of TQ at low speed per wheel. Hence why this Rivian having a hard time with this moderate obstacle was readily apparent. This was also readily evident shown by on a cool mountain trail, the Rivian cooling fans kicked into overdrive on this obstacle as the wheels with traction touching the ground were being fed incredible amounts of power.

The Rivian motors could have been getting so hot from the near zero high current torque requests that they were being de-rated too. Rivian is also a quite heavy vehicle, it's no small matter to lift 7K lb up an incline with no momentum. Weight is the enemy of off-roading.

I believe what I am showing above will bare itself out more as the Rivian is off-roaded more and more. Inclines with rocks are going to be its nemesis.

The Rivian will most likely be limited to 3, maybe 3+ difficulty trail on the top end:

https://www.of4wd.com/education/trail-ratings/

I’m not saying everything mentioned here is wrong but the R1T has been filmed on harder trails and obstacles such as Hell’s Gate in Moab so objectively you’re already wrong when you say it is limited to a 3 trail. I’m in Moab so I can say with confidence the Rivian will be fine on most 4-5 trails with the stock tires and normal ride height. I suspect the main issue will be departure angle. Based on what you said with 10k lb ft of torque I doubt any Rivian will have issues with the right driver and most drivers either aren’t that skilled or not super tempted to test the limits of a (market price) $150k rig that cannot be repaired or replaced easily. It will get interesting once a skilled driver starts to mod and test their rig publicly at the limits.

The Rivian in normal mode did 510+ on a ramp articulation test so as far as specs it should be pretty capable with the 34s and the normal ground clearance .

Not sure if you saw the Rivian take the famously tight switchback on Black Bear Pass with the supposed “expert” driver in the Motor Trend fluff piece where they drive across America…. but better off-road Rivian content is desperately needed. Cruising through the forest or wading through some water isn’t mind blowing off-road wizardry and that MT guy very potentially damaged the car and they acted like he didn’t.

If Whistling Diesel can recklessly flail a Hi Lux through Hell’s Revenge and film it some other rich YouTuber should be able to do a lot more than that with a modded R1T. Or at least talk about the challenges with increasing tire size etc. given the suspension limitations.

 

[cardad]

Basically any of the obstacles on the Rubicon trail. I'd pay to see a Rivian do the trail. If not anything, to see what its real capabilities are.

I have not seen a video of the Rivian doing any difficult trails. The closest was Hells Gate in MOAB, which actually isn't that difficult (solid rock with a lot of traction).

BTW a 34" tire on a 20" rim doesn't leave a whole lot of tire side-wall left when you air down. For those that aren't into off-roading.

Hell’s Gate “isn’t that difficult” to the right driver or someone with a decent spotter but it is still steep and technical and taking the wrong line will f up your vehicle instantly so I wouldn’t be so casual here in calling it easy … most passengers will prefer to walk it than ride along because it’s scary when you can’t see the ground. Notably they appeared to use the high ride height mode which makes the suspension overly stiff.

My understanding is that Rivian doesn’t need lockers because they have 4 motors and software can control the wheels independently based on the specified “mode”. Again, I’m guessing that with only a 29 degree departure angle (Wrangler 4xe > 35) the problems will have more to do with scraping the tail on many of these steeper drops. The approach angle also doesn’t quite match the mechanical capability (~35 vs Wrangler/Bronco ~44) so will we ever see most people go nuts rock crawling this thing? No but Whistlin Diesel has the budget to do it so it will be interesting to see someone with the balls to mod the R1T to tackle some real trails (which on further inspection would probably require some serious body modification ? as those stock wheels seem to barely fit the wheel wells.)

 

[SoCal Rob]

I'm just saying being an avid off-roader, expectations have to be managed. The Rivian capabilities aren't going to be as good as I had originally envisioned. I'm still buying the R1S though.

If you’re an avid off-roader with a ton of experience on the same type of vehicle (say Wrangler or Tacoma with live axles and a fixed height suspension) then you definitely should manage your expectations… or adjust your driving style to take full advantage of each vehicle’s strengths.

Our Land Rover LR3 is a lot closer to an R1S than a Wrangler or Tacoma because it has a near 6,000 pound curb weight, fully independent height-adjustable suspension, and drive modes which alter the suspension setting, throttle mapping, and traction control strategy. It was weird when we first switched to it from our Discovery 2 with its live axles and low-hanging differentials. However, it didn’t take me long to figure out that we needed to drive our LR3 very differently over obstacles compared to our Discovery 2. I read up on the drive modes, suspension settings, and locking differentials: center and rear with open diff and traction control on the front. As it turned out, the stock LR3 compared to the stock Disco is both more capable AND more comfortable when driven properly for the vehicle’s design. A large part of this was because without pumpkins in the middle, you can raise the vehicle and just drive above (not on) many obstacles.

As an example, we had a couple friends with us on a little off-road adventure yesterday. Our friend Steve is a long-time Jeep guy who spent most of his time in upstate New York and Maine. When we approached a high-incline slope composed of bowling ball sized (and smaller) rocks we put the LR3 in off-road height and low range. We knew from experience that we didn’t need rock-crawl mode. After an out-and back trip he said that he wasn’t surprised that the vehicle could do it but he was surprised that this big and heavy stock vehicle could handle the obstacles with so little drama. He said it was almost boring compared to what the experience would’ve been like in his Jeeps. No throwing of levers, no airing down, no roaring engine, and no scraping on anything. He was quick to point out that the relatively boring behavior is very appealing. This is in a 2006 vehicle with over 233,000 miles on the odometer and relatively low torque and horsepower to weight compared to an R1S. Unlike a vehicle optimized for off-road use, it’s also smooth, quiet, and comfortable at 70+mph with very good on-road handling. There’s no possibility of death wobble, either.

My expectations are that the R1S will do much better than our LR3 both off-road and on-road while being even more comfortable in the process.

 

[Acoustic71]

Watched this video and didn't come away exactly impressed with the Rivian Off-Road. And it's a pretty easy trail they took.



Thoughts?

And the Rivian bashing continues in 3.....2....1

 

[OrthoBlock]

...I only watched the first few minutes and all I could think was "damn dude give it some throttle."
rawl too which means the throttle is mapped for a lot of pedal travel to get power delivery.

...To me, it looked like he was babying the throttle and once he finally gave it enough juice he rolled right over. That's user error.

Other people driving the Rivian have commented that there is a ton of pedal travel in Rock Crawl because it's speed limited. I think he probably felt like he was giving a lot of throttle but in fact he was barely giving it any...

The evidence that little power is being drawn is visual. No wheel is spinning fast against substantial load...

Nothing I saw in this video makes me believe the R1T software needed tweaking to perform well on this trail. The driver simply didn’t have the experience to know what to do. Most likely, the R1T “struggled” due to pilot error.

Unless I missed something in the video, I don't believe we "know" what the driver was or was not doing with respect to the inputs for the vehicle (e.g., how much "gas pedal" was being pressed--he might have been flooring it the whole time, for all we know we have reason to believe that some pedal travel was left, but don't know how much)

Combination of not knowing how the different drive modes are programmed (E.g., the extent to which off-road modes allow for tires that are off the ground to spin at high rates of speed), and not knowing the inputs that were given, I believe we do not have enough data to assert whether the issue was with the truck or with how it was being driven.

I look forward to more data points...

 

[r1t_kev]

(e.g., how much "gas pedal" was being pressed--he might have been flooring it the whole time, for all we know)

There was a discussion between Kyle and the driver about this in the video - the driver mentioned that he "had pedal left" and was driving it more like a conventional vehicle out of habit.

 

[OrthoBlock]

There was a discussion between Kyle and the driver about this in the video - the driver mentioned that he "had pedal left" and was driving it more like a conventional vehicle out of habit.

Good point. Fixed in my post.

 

[Zybane]

I'm curious; since everyone's thought here is the solution for the Rivian to better accomplish that mundane obstacle is to "floor it", what is to be done on an actual difficult obstacle?

 

[zipzag]

 

[rydb]

I don't think floor it in rock crawl mode is actually all that much throttle in any other mode. speed is limited to 20 mph i think. I guess i'll have to play around with mine and see. actually haven't put it in rock crawl mode yet to even experience that different throttle map.

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