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Ask HN: Tesla Chose Unibody over Frame for CyberTruck. Why?
I was chatting with a friend about Land Rover and Range Rover. And he said that the newer Land Rovers are all unibody and completely denounced them.
Otoh, Tesla Cybertruck supposed to be competing with a F150 is Uni body. Why? Aren’t trucks safer with Body on Frame?
Or is there something special about Cybertruck design?
- Andys 6y agoHere's how I see it: the Cybertruck is more of a "sports lifestyle" truck and less of a daily utility work-horse. It isn't going to be feasible to tow trailers or carry bulky payloads in the tray on a regular basis. Traditional trucks are good at those things, but have terrible aerodynamics compared to a car-like construction. Going with unibody will make it easier for Tesla to manufacture using the techniques they already have working well, as well as take care of creating the battery storage bay at the base in one swoop.
- jelliclesfarm 6y agoRWD has 5000 lbs towing capacity and AWD is 10 and 14k each for dual and tri motor models.
- Andys 6y agoThe towing capacity could be handy for occasional use, but it will dramatically impact vehicle range, not to mention makes recharging a huge pain (public charge stations don't usually make provision for trailer parking)
- brudgers 6y agoUnibody can provide a lower floor height than body on frame. For a pickup that means bed height and with a load that means a lower center of gravity (and easier loading/unloading by hand). For an electric vehicle, there's not a lot of reason to provide a drive shaft from front to back, so the depth of the frame has even less rationale. The same is true if the vehicle is front wheel drive as is the case for Ram Promaster (Fiat Ducato) cargo vans. And the Ram Promaster is a real truck available as 1/2, 3/4, and one ton ratings. All are rated at 5000lbs towing capacity and 11,000lbs GVW. Even available as chassis only. There's folk wisdom and then there's automotive engineering.
- jelliclesfarm 6y agoI see what that means..cybertruck only has 16 inch clearance and has 14000 lbs towing capacity. I think I have to go see the reveal video again. Intuitively i like the design but I also want to understand the physics of it.
- brudgers 6y agoAcademically, clearance is unrelated to frame versus unibody. In practice, body on frame facilitates lifting the body to provide additional wheel clearance and more substantial suspension modification and/or larger diameter tires. e.g. more options for lift kits. On the other hand, any vehicle with 8" or more of ground clearance qualifies as high-clearance and is reasonable for BLM, Forest Service, and Park Service roads designated "High Clearance" under ordinary conditions. Unibody allows lower floor height which is not the same as ground clearance. It's more closely tied to step-over height for entry/exit.
- jelliclesfarm 6y agoI see. Thank you. I can visualize it better now. In the case of Cybertruck..the batteries will be in the underbelly/chassis making it ‘bottom heavy’ ..would this be right?
- brudgers 6y agoI would imagine so. An electric vehicle doesn't have much relevance to where and how I travel so I don't know much about what's available.
- jelliclesfarm 6y agoThanks. Your comments were very helpful.