back bone vs ladder frame

[Buzzmobile]

Is the back bone that much more stable than the ladder? Is it all that it is hyped to be? Who are the brands with the backbones? I know that Upton's has it, maybe JBL?

[Dubbs]

I am very surprised at the lack of reaction to your thread. Are there no "BACK BONES" out there?.

[strictlypersonl]

I would hesitate to describe the RUCC chassis as backbone. The only true backbone chassis that I know of are JBL and a British one whose name escapes me right now.

[48 IDA]

The only back bone frame cars I know of would be the
Lotus Elan, and Lotus Europa
Both very small and light cars.

Don

[Mike Jones]

Backbone vs Ladder Frame

I have an RUCC and instead of telling you how much I like it and the main reason I bought the car was the backbone frame. I would recommend that you buy or at least read Chassis Engineering by Herb Adams. I'm not a automotive engineer but Herb is and he also designed the VSE cobra. After you read his chapter on frame design there will be no doubt what the different is between the two frames and that the RUCC is indeed a backbone frame. Both frames have there place but learn from one of the experts what that is and which one would be the best for you. When I was doing my research on which cobra kit to purchase I went to the RUCC shop and spoke to Roger Upton the owner. Roger at that time had both a ladder and backbone frame (he makes both). During a test drive under hard acceleration the gap between the top of the door and body would flex open more than half an inch on the ladder frame and not move at all on the backbone frame. Read the book you decide.

Mike

[Ant]

I have a ladder frame chassis which looks similar to an ERA 4x3 chassis, I have raced with these chassis from Almac Cobra (NZ) the chassis is what we term here as a sportsman, these suit most people and do a good job, and are accepted as being in good taste compared to an original.

If you are like me and want to win races then they are limited, if you get the springs and dampers right etc good tires and heaps of grunt, you can beat them on the straights and have them bugging you in the turns. So this time around I want a stiffer platform that still has the original looking cockpit areas.
I am going to replace my 4X3 with 3X3 RHS main rails a weight saving of approx 150Ibs, fit a backbone to my chassis, similar to the Cobra coupe, if done properly it should improve torsional rigidity by at least 50% and add about 80Ibs of weight back.
I was going to build a space frame but they are frowned upon in the classic racing I want to attend!

[Dan Stryffeler]

ERA has a really good comparison of the theories behind the different frame types. It is on their site at -

http://www.erareplicas.com/427/deslogic.htm

- Dan

[wilf leek]

UK manufacturer of Cobra replicas with a backbone chassis is Gardner Douglas.

Much is made of the improved abilities of their chassis, although personally, I do not care for the shape of their body shell.

They do have a website where you can look at the chassis etc. url escapes me for the moment, but I am sure a quick google search on their name would bring it up if you were so inclined.

I have never noted any chassis flexing on my own car, which has a ladder chassis extremely like a Kirkham or Shelby, at least not in terms of door shutlines varying. And it does get some serious "stick".