Suspension Design

[intrepid44]

Would this actually work?... or be any good for that matter.



The idea being that it reduces weight, and acts like a ARB as well, obviously the rest will be double wishbone design, and yes my paint skills are that bad.

[Project 644]

Yes and no. Yes with no roll being put on the car and both wheels moving up and down in relation to the chassis at the same time, it is a standard Monoshock system. However in roll the two bellcranks could/would pivot the same way with the spring and damper doing nothing to stop the chassis from "falling over".

What you want to add is some droop stops to the bellcranks, so they can't go in a minus direction (if that makes sense?)

[P924]

It would only 'work' when the road was flat. If there is any camber, then the 'system' doesn't see it.

[T89 Callan]

It would work in equal bump but not at all in roll.

[mrmr96]

There's no ARB effect possible in the system which you've drawn. Have you misunderstood how an ARB works, or is there something missing from your picture?

[P924]

It would only 'work' when the road was flat. If there is any camber, then the 'system' doesn't see it.

[andygo]

Are you a Mclaren designer?

I noticed I was missing some plans for my proposed new F1 car. Can I have them back please, I'm off to Legoland tomorrow for a test build.

[Galileo]

Sorry to rain on your parade, but I think this is what's known as a Zero Roll system and has been used in Formula Vee for some years. It works really well with the swing axles that are used, due to the way they change camber during chassis roll. The chassis roll is then controlled by the front suspension.
Not sure how it would work with other suspensions as there is no roll control.

Edited by Galileo on Thursday 8th October 12:21

[The Wookie]

You would need to have some stiffness in the mount between the bell cranks and the chassis

[Project 644]

Galileo said:

Not sure how it would work with other suspensions as there is no roll control.

As I said above, you would use droop stops so that the suspension has something to work against when in roll.

[zac510]

P644, not unlike a monoshock where you have belleville washers for the roll control? The washers acting in compression rather than rebound like the bumpstops, but still undamped.

[tristancliffe]

The droop stops are great, but what about if the car isn't at full droop when the car turns? It would fall over until it hit the droop limiters, and then the wheelrates would instantly jump to some horrible figure...

To make the car work properly (without FVee suspension!) you'll need to ensure that there is always some roll stiffness no matter where the suspension is in its travel.

[spitfire4v8]

I made exactly what you have drawn for my radio control car as I wanted no front roll stiffness at all. It had effectively swing axles on the front so it's interesting to see it's also used on some swing axle race chassis. It didn't work very well on my R/C car though.

[Project 644]

zac510 said:

P644, not unlike a monoshock where you have belleville washers for the roll control? The washers acting in compression rather than rebound like the bumpstops, but still undamped.

Yes, the system is a monoshock in essence. The lack of roll resistance is it's downfall (unless that is what you are looking for). A traditional monoshock system with either belleville washers or compliance springs of some sort has it's limitations too.

I am currently assessing a monshock system that "could" possibly control 4 wheels. The downfall of the system, I feel, will be that the damper will be overworked. But if it does work out it will save quite a lot of weight.

[zac510]

Here is a monoshock with belleville washers, for those that are interested:

[nick997]

Nicely engineered zac510, what is that?

[zac510]

I am quite sure it's a Force (hillclimb) chassis but I didn't tag the photo when I uploaded it!

[nick997]

Thanks, very tidy with few parts, thought it might be F3 or the like, i.e. "serious" motorsport

[CNHSS1]

it is serious motorsport, hillclimbing FTW. The motorsport definition of lateral and innovative thinking

[zac510]

Hell yes those hillclimbing guys are serious

I think the F3 did go through a bit of a monoshock fad for a while there but these days they seem to be swinging between 2 and 3.