Home » I’m An Ex-Tesla Suspension Engineer Here To Tell You: The Cybertruck’s Front Suspension Is Not ‘Terrible Engineering’

I’m An Ex-Tesla Suspension Engineer Here To Tell You: The Cybertruck’s Front Suspension Is Not ‘Terrible Engineering’

Cybertruck Spindle Fine Ts
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After many years of delays, Tesla is finally bringing its new Cybertruck into production. And while the styling is extremely polarizing (our own David Tracy likes it now that he’s seen it in person, but what I’ve seen driving here on the road makes me wonder if he needs to see an optometrist), there seems to be one small detail that has both Tesla fans and Tesla critics up in arms. It’s the front suspension.

Specifically, it’s the stud coming from the upper control arm through the top of the steering knuckle.

Vidframe Min Top
Vidframe Min Bottom

What this commenter is referring to is the location of the upper ball joint in the front suspension and the fact that it appears to be placed over top of the tire. While I personally haven’t seen a Cybertruck up close, I can assure everyone that this type of suspension design is extremely common and has been on production since the late ’70s when it was first introduced by Mercedes in the W123.

It’s called a “tall spindle double wishbone” or “tall spindle short/long arm (SLA).” The concept is the same as I described here on the Can-Am Maverick and is one of the most common front suspension designs on the planet — second only to the ubiquitous MacPherson Strut.

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Mercedes uses it. BMW uses it. Ford, GM, VW, Jeep — they all use it. In fact, I can’t think of a single car and truck manufacturer that doesn’t have some form of an SLA in production. Even Tesla uses it on the Model S.

I think what is throwing people off is the fact that the upper arm is so visible in the Cybertruck. Most cars have a much smaller fender-to-tire gap, so the upper arm is only visible if you get up close. With the Cybertruck’s large fender opening, the suspension is very visible, and a shiny aluminum part really stands out.

What this design DOES do, however, is eliminate your ability to install larger tires. A larger tire would interfere with the stud of the ball joint so it just wouldn’t fit. Most trucks that use SLA’s (like the F-150, for example) solve this problem by placing the upper ball joint next to the tire. This keeps it out of the way of a larger diameter tire. It also makes the upper arm and ball joint more difficult to see which is why many people don’t realize these trucks have such a suspension design. You can see that here on my 2020 F150:

F150 Ball Joint

While the commenters have not been very specific about what aspect of the design constitutes “terrible engineering,” one problem that could arise is susceptibility to damage from rocks and dirt thrown up by the tire in an off-road situation, especially to the rubber boot retaining the ball joint grease. If this boot were to get damaged, the ball joint could fail prematurely. I’m not familiar with the off-road durability testing Tesla would have done; I suspect if this had been a problem, it would have been addressed. We’ll have to wait and see what customer experience tells us in the coming years, but a fairly simple shield could be made to prevent direct impingement of debris against the boot if this does turn out to be a problem.

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[Ed Note: Jeep uses a similar setup on some of its off-road vehicles, like the Grand Cherokee. Check it out:

Notice how increasing tire size would definitely yield rubbing. -DT]

Here’s another comment from someone who thinks the Cybertruck suspension is somehow inferior:

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This commenter states that the Cybertruck clearly just uses the Model Y suspension and how could that possibly be good enough for an off-road vehicle? Let’s take a look at the upper arm of the Model Y suspension:

Tesla Model Y Front Suspension Upper Arm Mounting
Screenshot: Munro And Associates

Notice how the upper arm bushings use a cross bolt to attach the arms to a small casting that also holds the upper spring mount. Now let’s look at the Cybertruck upper arm mounting:

Notice how the upper arm here is mounted to the vehicle in a completely different way. The bushings have what is commonly called a “dog bone” or “bar pin inner metal which is then bolted to a casting that is part of the body structure while the upper spring mount is separately attached to the body. These are clearly NOT the same design or same parts.

Lastly, remember earlier how I said this type of suspension design would not allow a larger diameter tire to be installed? The Model Y uses a P255/35R21 tire size which has a diameter of 712 mm while the Cybertruck is equipped with a P285/65R20 tire which has a diameter of 878 mm (about 35 inches). That’s a difference of over 6 inches! Clearly, the Cybertruck tire would not fit on a Model Y suspension so they simply cannot be the same. They use the same architecture, that is true, but they use completely different parts and execution. The Cybertruck suspension is much bigger and I’m sure much stronger than the Model Y.

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All in all, the Cybertruck, while polarizing from a styling standpoint, shouldn’t be polarizing from an engineering standpoint. I can tell you from personal experience that Tesla engineering is second to none. Say what you will about the cars themselves, say what you will about Elon Musk, but Tesla engineering is exceptional. That’s why it remains the standard by which all other EVs are judged.

And the Cybertruck front suspension design most definitely does NOT represent “terrible engineering.”

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Mr Sarcastic
Mr Sarcastic
7 months ago

Well I’m no expert. (Everybody reading says that’s for sure) but as long as offloading doesn’t cause the nipple to puncture the tire I don’t see a problem.

Pedro
Pedro
7 months ago
Reply to  Mr Sarcastic

THAT’S WHAT SHE SAID!!!!!!

Mr Sarcastic
Mr Sarcastic
7 months ago
Reply to  Pedro

That was quick. Yeah she said that too

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