37 replies to this topic

[Hworth08]

A couple thousand years ago, after Cox released the Cuc, everyone at our local track just knew the Iso had to be better. Most everyone built one with the same results Tony had!

[tonyp]

In the glue days they ruled!

The Iso Story

[tonyp]

The Iso was the first step in chassis evolution where the weight of the chassis was concentrated on the guide. We started out running with a spring on the drop arm like we did with our drop arm cars. As the glue got heavier we removed the spring and eventually spaced the front tires up off the track surface.

When limited glue came into being it was right at the same time as PdL's "Diamond" style chassis was born and that was the better design. It was the next step in the evolution to no wheels at all. We still ran Isos on certain tracks for some time after that, especially at our two Engleman tracks, Clementon and Elmsford.

[GTPJoe]

Hi Tony!

Sir, when did the drop arm cease being dropped?? In other words when did it become soldered solid as a center section? (Say that ten times fast!)

As always,

Thanks!!

[tonyp]

The Iso pictured in Rick's replica article is 1975 vintage. The article in the MAR newspaper was Dec '72, So I would think early to mid-'72 based on the chassis designs shown in the article.

[Prof. Fate]

Hi,

The Midwestern guys commonly didn't use drop arms. I did both Midwest stuff and more SoCal stuff. In '66 at a race on an American black using a SoCal type piano wire car, the '66 Ferrari that Keith photographed at the convention, I broke the hinge at the end of a heat in a crash, ran over to the bench to hurridly solder it up, got solder in the hinge. And it went faster. Did a few tests and didn't use a drop arm again.

P is the first pro to openly mention in the press that he didn't do drop arms.

Fate

[idare2bdul]

It makes more work for the tech crew. The chassis will have to be teched on a block with a recess equal to that of the track so the guide is against the "braid" supporting the weight of the center section, clears .015" in the front and the front wheels are touching.

In D3 there is a different rule for tech in that the guide can't be used that way. There is a hole for the guide to go through and the front wheels must support the weight of the chassis. I can't remember any other tech ever doing this but we have had few complaints.

[idare2bdul]

P is the first pro to openly mention in the press that he didn't do drop arms.

While PdL raced in our recent Legends of the 1960s Race I think his fame(infamy? ) was mostly achieved in the early to mid-'70s when the drop arm had lost some favor.

[Cheater]

In D3 there is a different rule for tech in that the guide can't be used that way. There is a hole for the guide to go through and the front wheels must support the weight of the chassis. I can't remember any other tech ever doing this but we have had few complaints.

Mike,

SERRA techs cars the same way: only the front wheels support the front of the chassis during the checking of the front chassis clearance. I believe this is identical to what IRRA does as well.

[Noose]

Yup... we do.

[tonyp]

The center section on a drop arm car or Iso can sit below .015" if they are teched on a block where there is just an open space for the guide to sit. An Iso by design does not have the front wheels support the chassis weight.

[idare2bdul]

From the remark about the guide recess I thought you guys did something different. It's nice that the tech rule is essentially the same.

[tonyp]

Mike,

Basically yours and the Foamster's drop arm cars technically can run illegal on the track. LOL.