[Russ Noble]

Originally Posted by Big-Foot

Scott - It is you that needs to do this research. I've done mine. As I said before, all chassis need to have some degree of compliance (read flex) in them to work properly.

The wing tips on a 747 flex up/down up to ~4 feet.
Buildings are engineered and built to sway a certain amount in the wind.

I've been building chassis for racecars for a lot of years. Many of my own design. From Karts to Top-Fuel Dragsters and most everything in between.
One of the types of racecars we built and fielded were Late Model Stock cars for both Dirt and Asphalt. Before you automatically discount these cars as garbage like so many of the road-race crowd do, understand this - We were putting down 800+ HP to the ground with a car that weighed 2300# with driver on a track that's rougher than the south-40 of the Ponderosa ranch. Hi Randy, is this what we Down Under call Sprint Cars? Years ago the NZ Sprint Car Champion at the time used to work for me, so I am a bit familiar with those cars and used to help him in the pits from time to time, so I have a lot of respect for the specialised engineering and setup involved. He used to run a Gambler chassis when they were the hot thing out here.
These chassis, when new, were rockets and handled quite well. As the chassis' aged, they would work-harden and get stiffer overall. They handling of these chassis were exceptionally difficult to get hold of. Part and parcel to the hardening of various parts of the chassis at different rates. We finally got a handle on how long it would take Mild Steel to stiffen and how long it would take CM to stiffen up. Work hardening is caused by chassis flex? You are building them like a gokart so the chassis is part of the suspension? We could only! get 20 races from the mild steel No wonder! and half again more from the Moly.
We would sell these used chassis to "Budget" racers that would run them until they broke.. Some used our old chassis to clone them and make their own. Pity that few of them really understood how to properly weld and anneal.

Guys would come out there with very stiff chassis' from time to time - Sometimed they worked pretty well - most of the time they would not do well at all..

Regardless of the venue, if you build it too stiff, something will break. Sounds like a design flaw in the component that breaks or the one that acts on it! Maybe beefing things up so they don't break carries too much of a weight and performance penalty. So you build them light, tune them to suit and throw them away after 20 races?

Your challenge is as it was before - finding out where to draw the line.

or

To pay someone else to do it for you....

IMHO.

Cheers,