s-DRIVE: up to 300% higher power-to-weight than drivetrains used by major EV brands

[Logic]

If the unsparing weight of these hub motors can compete with std wheels these guys are onto something.
https://www.s-drive.tech/

[redpoint5]

Very neat, but I consider unsprung weight to be behind other shortcomings of hub motors such as durability and power output. I realize things are typically improved incrementally though, and this would be a good incremental improvement. Perhaps it has improved upon the durability issue as well?

[Logic]

Originally Posted by redpoint5

Very neat, but I consider unsprung weight to be behind other shortcomings of hub motors such as durability and power output. I realize things are typically improved incrementally though, and this would be a good incremental improvement. Perhaps it has improved upon the durability issue as well?

From what I recall power... well torque is not the problem.
Power is just 'torques' x rpm after all.
4 bog std Chinese hub motors, in rims, have 1400Nm from 0 rpm!
Enough to pull a train!
https://www.qsmotor.com/car-motor/

If you're talking hub power or unsprung weight per kg; well that's a different story.
A light motor is generally a weak motor.

But these guys seem to have decent numbers.

As it's open:

https://www.youtube.com/watch?v=KdfmuKH1K-k

[redpoint5]

As the title suggests, the main problem they are attempting to solve for is power to weight ratio.

Unsprung weight can probably be mitigated by active suspension systems, or other means.

As with everything, it all comes down to delivering the best/acceptable metrics across all of the characteristics at a lower cost. If this is more affordable and delivers similar performance to frame mounted motors, then there is a market for it.

[freebeard]

I, for one, appreciate the wide five bolt pattern.

Originally Posted by redpoint5

Perhaps it has improved upon the durability issue as well?

Each lug bolt is carried in a bushing that acts as a shock absorber.

[Logic]

Originally Posted by freebeard

I, for one, appreciate the wide five bolt pattern.

Each lug bolt is carried in a bushing that acts as a shock absorber.

At a guess these are (look like) rubber mountings, much like engine mountings.
Normally I'd say that does a good job of absorbing high frequency, low amplitude vibration, but there's the tire doing that already. [Shrug]`
Perhaps such vibrations in the circumferential direction? From the motor??

[redpoint5]

Now y'all got me curious about the engineering reason for it.

Considering motor mounts are always going bad, I wonder why they don't just engineer them better? I'd be willing to pay a dollar more for a vehicle with bombproof motor mounts.

[freebeard]

I'd speculate DDG/?q=elastomeric+snubber.

The pneumatic tire is what makes cars possible at all; OTOH the VW Tpe III with rubber-mounted front and rear subframes rides much nicer than a Beetle on the same wheelbase. So....

Redundant levels of absorption can't hurt. Hubless 19's with i3 tires would look wicked on a Type III Notchback.

[freebeard]

Simulpost at Today, 03:17 PM!

[redpoint5]

Originally Posted by freebeard

Simulpost at Today, 03:17 PM!

My bullet was probably in the air as you were pulling the trigger.