Reducing Losses in the Rolling Chassis

[NeilBlanchard]

Thanks Patrick -- I think the key phrase is "so long as the terrain has a significant roughness in relation to the wheel diameter"

Roads are typically fairly smooth, and other than potholes, they do not have "a significant roughness in relation to the wheel diameter". Nothing a little experimentation wouldn't help determine.

[jamesqf]

Originally Posted by dcb

these guys don't flex much

Yeah, but if you cut off the flanges, they corner like cr*p :-(

[jamesqf]

Originally Posted by NeilBlanchard

Roads are typically fairly smooth, and other than potholes, they do not have "a significant roughness in relation to the wheel diameter".

Err... And where do YOU live? Around here, a good many roads (the major paved ones, not dirt or paved side roads) are pretty darned rough. I can & do see significant differences in real-time mpg on different stretches of (level) road. And of course there's I-80 over the Sierra: the last time I drove that, I was worrying about high-centering on the ruts that traffic had worn into the concrete.

[Frank Lee]

I'm in the Not Ga Ga Over Solid Tires camp.

I think bicycles offer the perfect illustration why. For decades my ride was a Fuji road bike with 27 x 1 tires at 105 psi. I still have it but now I much prefer to hop on my full-suspension mountain bike with 26 x I think 2" slicks at 65 psi- and that's just for going around town 100% on pavement. The comfort factor in favor of the MTB is practically beyond debate, but I've found the r.r. on the much heavier bike with the lower pressure fatties to be very favorably comparable. So I'm not beat up OR worn out when I get there.

You know, once upon a time solid tires were the standard and pneumatics shoved em out of the market partly because of the rolling resistance improvement- as noted in a previous post.

I suppose if a vehicle rides like crap it would save gas... cuz nobody would want to use it unless it was absolutely necessary.

That said, I could totally get behind a compliant yet airless tire system, if only to address my impression that only, oh, 10% of the motoring public knows what a pressure gauge and air hose are for.

[Laurentiu]

Originally Posted by Frank Lee

I'm in the Not Ga Ga Over Solid Tires camp.

well, there's solid tires and there's airless designs of tires (a.k.a. "tweels"), totally different things.
We have to look out for these in the future when they manage to outcome some of their drawbacks (such as vibration &noise)


Video

[CapriRacer]

I think you'll find the airless tires has more mass than the pnuematic tires - which is probably why you haven't heard much from the vehicle manufacturers on this subject.

[TheEnemy]

Originally Posted by jamesqf

Err... And where do YOU live? A good many roads (the major paved ones, not dirt or paved side roads) are pretty darned rough. I can & do see significant differences in real-time mpg on different stretches of (level) road. And of course there's I-80 over the Sierra: the last time I drove that, I was worrying about high-centering on the ruts that traffic had worn into the concrete.

I had the same thoughts, ouch. New Mexico is NOT known for smooth roads, and those are the ones that are paved.

[TheEnemy]

Originally Posted by Laurentiu

well, there's solid tires and there's airless designs of tires (a.k.a. "tweels"), totally different things.
We have to look out for these in the future when they manage to outcome some of their drawbacks (such as vibration &noise)


Video

Are they planning on sealing up the sides of those tires? I could just imagine getting 5lbs of mud stuck into the side throwing them way out of ballance.

[NeilBlanchard]

You of course, would have to tune the suspension to work with solid/airless tires. And if you did have regenerative shock absorbers, the solid tires would "pass along" most of the energy to the shocks; rather than the tire heating up.

The "TWEELS" are all made to work just like pneumatic tires -- and not only with dirt/mud/snow build up in those open cells -- the aero drag from these is pretty horrible, too.

[TheEnemy]

I'm not going to say it cant be done, because suspension systems have advanced so far as it is, but running a solid/airless tire makes it harder to get a smooth comfortable ride that will be necessary for the masses to accept them as an option. On top of that the transition to motors in the hubs is going to increase the unsprung weight putting even more demand on the suspension to smooth things out.