Reducing Losses in the Rolling Chassis

[Phantom]

I do not care much for hub motors just think what happens when you hit that big pot hole that looks like a puddle and you pop your tire and bend the rim. Time for a new motor.

The tweel is a neat concept and could be a viable choice if they fix the high speed vibration, noise, and heat issue. Probably could be fixed by sealing the sides and placing it under a slight vacuum.

Has anyone tried reducing the weight of a vehicle by sealing the frame of the car and filling it with helium? I know that it sounds ridiculous but if it is not under pressure the air gap in the frame will be lighter and since it is a noble gas it will not react with the metal and cannot ignite.

[Frank Lee]

Re: Tweels and such: I'm certain the engineers did not overlook the pitfalls of the open architecture. It's just that a marketing presentation for the concept would fall flat (pun!!! ) if sidewall membranes were installed and the thing looked just like a conventional tire.

[shovel]

I think airless tires have one MAJOR drawback:

People.

A pneumatic tire can only be neglected until it pops, and then the user MUST replace it.

Airless tires would need some way of becoming absolutely undriveable when worn past safe margins, or you know a good 20% of the people on the road would just keep blindly driving on them 'till they're 10" diameter and the brake disc was contacting the road.

What I want to know is where the F are our peristaltic self inflating tires? Been hearing about them forever but when I visit the tire store they just aren't there.

[RobertSmalls]

"Lack of tire pressure maintainence" i.e. people, is the biggest problem with pneumatic tires, and the best reason to install twheels. I'll stick with my LRR pneumatics for the forseeable future, of course.

Once the twheel runs out of rubber, and the steel meets the road, it will be sufficiently undrivable for lack of traction that the people you refer to will have to apply a can of spray-on undercoating, or screw scraps of old tire to their bare twheel.

[Patrick]

Originally Posted by Phantom

Has anyone tried reducing the weight of a vehicle by sealing the frame of the car and filling it with helium? I know that it sounds ridiculous but if it is not under pressure the air gap in the frame will be lighter and since it is a noble gas it will not react with the metal and cannot ignite.

There's not enough volume there to make it worthwhile. You need hundreds of thousands of cubic feet.

[Bicycle Bob]

Someone did make a bicycle frame of tubing about the gauge and size of a soda can. Air pressure was used to prevent buckling, and it did come out somewhat lighter. Unfortunately, the wind resistance issue was more important.

I saw a picture of an Atlas rocket in a museum. Apparently, the upper fuel tank is so thin-walled that it too needs pressure to support the payload. Unfortunately, the museum air supply had failed, and the rocket looked, shall we say, unable to penetrate. :-)

[NeilBlanchard]

Other issues that relate to rolling efficiency:

Wheel Alignment while rolling straight and while turning.

Dragging/free spinning brakes

Wheel bearings -- wear and rolling drag.