Rutrow

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Tesla is going to have to design some super amazing rear axle / suspension system that can handle towing 14k AND now has rear wheel steering.

I have to keep telling myself the CT is a 1500 series truck. Maybe a 2500 sorta kinda wanna be.

I'm having mixed feelings about the rear wheel steering. RWS is definitely a step in in the luxury pickup direction, and a step away from a heavy duty truck you would want to tow with.

There are many ways to accomplish RWS.

Porsche has RWS on the 911. It uses variable length tie rods. Simple actually.

1625618072088.png
Computer controlled 4WS may have a positive impact on tow rating rather than a complication. The J2807 standard for GCWR includes a towing stability component that can be improved by 4WS. (See TFLT's trailer testing done with ZF's steering system )

I've wondered what the weak link tow rating component would be that decided the maximum tow rating for the CyberTruck. It would have no trouble getting a heavy trailer up to speed, no problem hauling up the Davis Dam incline without overheating, and no problem generating the torque needed for the 12% incline tests. I guessed that the stopping power would be the Achilles heel for CyberTruck, or the ability to minimize trailer sway. ZF's system (as seen in the above video) can increase the tow rating if sway is a problem, and since the stopping test has a "stay in an 11.5' lane" component, a computerized 4WS system would improve its ability to stay in the lane under heavy braking.

I really want the CyberTruck to increase the tow rating above 14K lbs announced at reveal, because I want my CT to pull my 5th wheel RV when I retire. 14k trailers are nice, but there's a LOT of other amenities to be had if you can step up to 16.5K. I will love it if the 4WS allows that.
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rr6013

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I've wondered what the weak link tow rating component would be that decided the maximum tow rating for the CyberTruck.
Brakesā€¦ stopping distance, curvy declines and emergency braking. Its just a pickup. As this forum is so enamoredā€¦itā€™s a F-150 size pickup.

Teslaā€˜s CT should spec closer to a F-250 at rollout. But even that simply is the wrong horse to pull your dream trlr.
 

Ryan95738

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I was very pleased that one of my most important wishes was fulfilled by Elon and the Tesla engineers.

What I have not read now in the 13 pages (or have overlooked)

Such a steerable rear axle has besides the mentioned advantages one more:

It is cheaper!

Have you ever seen a modern rear axle? So not the carriage rigid axles from the Middle Ages but the multi-link axles with very precisely specified links, elastic bearings toe-camber-caster changes depending on position and load vector.
And then a McPherson front axle on the same vehicle that is almost primitive in comparison.
Why is that?
Simply because the rear axle must steer for good handling, and why can the front axle be so primitive?

Because it is actively steered.

What does this mean for the CT?
The axle is more expensive than the carriage rigid axle of the current trucks, but the axle can be built primitive and cheaper if it can be actively steered, yes it can be built like a front axle, it could even be built from the same components like the front axle, the individual wheel suspensions could be identical, i.e. a pair of wishbones, an air suspension strut and that 4 times on each vehicle.
I had no idea of modern rear axles for so complicated due to the need for precision and nothing able to change actively if anything gets out of alignment. Thank you so much for your insight
 

dtruckman

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If this comes true, it will make backing a trailer or boat a breeze! It's a game changer. GM had that fir a while on the pu's but was too costly for them. Cornering and parking will benefit too.
 


rr6013

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I'm wondering if the CT is capable of doing the "K" turn as recently announced by Rivian in their patent. If so, can Rivian really patent it?
https://jalopnik.com/the-new-rivian-ev-could-get-a-neat-k-turn-pivoting-tric-1847247553
They wonā€™t get a patent on the software, logic or letter ā€œkā€ thatā€™s described and shown.

Rivian invents something new that provides functionality that enables a new steering capability, capacity or innovative safety integration - that new ā€œ somethingā€ responsible is a patentable claim.

Not seeing any claims so hard to tell what Rivian has claimed. Claims are the only thing that matters in a patent. So far Rivian seems happy to pursue ā€œClown Carā€ features that Abu Bekr Shriners would immediately have a good laugh with!
 

tmeyer3

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I'm unsure what the legal boundaries are, but I doubt the CT would be fit for a gooseneck or heavy pins, which is kind of the point of a dually? Do you have a 5er at 16.5k with a standard hitch?
 

FutureBoy

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An RV or city bus can weigh up to 40k without using duallies. So why would a truck even with a high tongue weight need them?

-Crissa
Because duallies look tough and add to your man cred.
 


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It's all about the tire rating. Tires can only handle so much weight, or burn up much quicker. Dual wheels spread the load. RVs and Buses have larger higher rated tires than truck. Just like fire trucks. It's all about the load rating. And, as FutureBoy said, "cool factor". peace
 

rr6013

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An RV or city bus can weigh up to 40k without using duallies. So why would a truck even with a high tongue weight need them?

-Crissa
Think about the fact that the trailer weighing 16500 lbs. is greater than and pushing the unit powering it thar only weighs 6000 lbs. A 10000 lbs difference is impossible for the power unit to control unless the trailer also is powered and under the control of the power unit towing it.

Barring that happening, little 6000 lb CT just gets push around curves, through red lights and over baby buggies that happen to suddenly appear.

16500 lbs is a three car hauler trailer. Iā€™ve towed one of those. It destroyed a F350 1 ton dually grinding the axel bearing into the spindles and vaporizing brake pads like they were made of cork. Yes it could pull 16500 lbs. No it could not do it repeatedly. That took an International 1850 series tractor(3.5 ton) and a real 5th wheel to handle the lateral loads.
 

drscot

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Elon never said it would have a crab mode. That being said. 4 wheel steering is a good thing and is in line with the independent steer by wire that I've hoped for in Cybertruck.
I agree. Crab mode might be good if one wants to park sideways in your garage just to get bypassers to scratch their heads, but as far as a consistently useful feature I'm not sure it would be worth the additional expense of design and installation, coupled with maintenance and repair when things do go wrong (and they will). Four wheel steering seems to have more everyday utility coupled with general simplicity of design, and I think that is what Elon is banking on. "Keeping up with the Joneses" isn't always the best approach. If General Motors wanted to launch a manned rocket to Venus or even Mercury, would it necessarily be the best idea?
 

happy intruder

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I 100% expected the new model S to have variable electric power steering. It might even have it just not activated yet because this is definitely what the yoke is for in actuality. I will bet a lot of money on the truck having variable steering at least if not at first than 2 years down the line.
the benefit of having a high reservation number
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