Wheels on agled shafts...

[Externet]

If the center of gravity is kept at the same place; the footprint of solid tires is equal and at the same distance,

What are the effects of angling the shafts as in this setting, instead of / compared to the 'normal' horizontal shaft

 

Why if the answer is stability ?

[moth]

Making the base as wide as possible increases stability because it's hard to lean far enough to get your

center of gravity over the base of the wheel.

Making the top of the wheels narrow makes the chair easier to push.

If the wheels were separated by more distance than the pushers' shoulders, the elbows would have to rotate up

and out to get your hands wide enough to reach the wheels, and the power of your stroke would be reduced.

[Externet]

Thanks.

I understand the convenience, elbows, shoulders and hands positioning... not part of the subject. The thing is comparing with another wheelchair with the same base width.

 

Take a 'normal' wheelchair and bring the high of the wheels inward, with same center of gravity. How that improves stability?

[John Cuthber]

Thanks.

I understand the convenience, elbows, shoulders and hands positioning... not part of the subject. The thing is comparing with another wheelchair with the same base width.

 

Take a 'normal' wheelchair and bring the high of the wheels inward, with same center of gravity. How that improves stability?

I don't think it would and I don't think anyone would do that.

[PaulSpring]

It's nothing to do with where the CoG is; as you rightly say, angling the wheels doesn't change that. Neither is it related to the width of the wheelbase. This setup is significantly more stable than the same wheelbase if the wheels were vertical. It's simple resolution of moments around the pivot point (the point where one of the wheels contacts the ground). With the angled wheel the sideways force required to tip the wheelchair is 1/cos(theta) times that for the same wheelbase and vertical wheels, where theta is the angle from vertical. So, with a 30 degree angle, the force required is 15% greater. In simple terms, you are using a greater part of the person's weight in opposition to the sideways force.