Rivian R1S
Sitting next to an SUV with that model designation. Nice looking rig, appears to be in the same chassis as pickup. No plates out. Marty
Forum Discussion
map40 wrote:
Most EVs have an electric clutch (or connect/ disconect) between the wheels and the transmission. They don't have many components but they have a single or in some cases a 2 speed transmission (very simple, nothing like what am ICE has)
I am learning, thank you. I assumed each drive wheel had a motor. If a motor is driving 2, (or more) wheels would require some kind of differential to allow for turns. (ICE, towing spinning at least 1 differential, plus overdriving the driveshaft(s)
Due to the high torque of the electric motors, the traction control systems are much more complex than ICE's and monitor wheel speeds with a much higher frequency and precision.
The same problem happens with the regenerative breaking in snowy/icy condition. It is very easy to loose traction on ice and as it is involuntary (meaning the driver does not press the brake or anything else, it is activated automatically) so the system is monitoring not only the wheel speed independently several thousand times per second, it also triangulates with GPS and accelerometers to ensure the wheels are always "in traction".
I can't see where this would prevent towing a functional vehicle, just turn it off. After all, if the road might be slick any driver that has head on shoulders, not between cheeks will turn off the jakes.
All of this said, the problem is that flat towing something that complex may create unforseen problems, so lawyers said "How many more sales are you going to get by allowing flat towing? Is it really worth the risk?" And the answer was always "No".
There is no inherent technical reason (like the transmission in an ICE), it is simply "Why risk it, we are selling every unit before its built..."
Yes, I can see this issue. But this is not a reason a DIY that knows the systems could not work things out.
I have towed one of my leafs and one of my BMW but just to see how fast did they charge, and o boy did they complained!
Complained? Often gearsets designed to be powered from one end will make noise if driven from the other, and if load is on the other end, spinning faster than
LOL, just thinking as I type I realize that the gearsets, driven backwards, spinning the input, even unloaded, faster than what is normally output, could in fact face same, or more problems as transmission of ICE. I now see why EVs not toads, without designed from start.
Thank you
