I have a 76 shovelhead, I'm told the frame is an arlen ness 70s digger frame, it's 7/8 diameter, 6 out and 4 up, I was also told the frame is made of cromoly, the frame cracked so before i get it fixed I need to find out if it's cromoly or not, and just curious if it's a ness frame or not any help is appreciated, just trying to find out a little history on it.
thanks,
Mark

 

...maybe you could contact Arlen Ness, his company not him directly, and see if there are any identifiable markings or serial numbers that could tell you it's history and authenticity.
Hell, maybe they'd even pay you a pretty penny for the frame for their collection/museum!
Just a thought.

GSF

 

I think that's my next step,
thanks

 

Pics?

I LOVE DIGGERS!

 

[QUOTE=KurseD;9902949]Pics?

I LOVE DIGGERS!!
Here are a few pics,

 

Dude cromoly is just a trade name for 4130 grade alloy steel it works and welds just like the regular 1018 most frames today are made from , it was just a bit stronger and lighter that's all . Some places years ago tossed the name around because it was one of the big buzz words with all the aerospace hype at the time .

 

are you serious ?

im a welder and fabricator and although i disagree with how nhra plays up 4130 it DOES NOT WELD LIKE ANY OTHER MILD STEEL it welds like 4130 cromo yes you use mild steel filler if tig welding and the grade depends on where the weld is what stress it will see and so on.either 70s2 or 80d2 you also need to know how to normalize the HAZ (heat affected zone) if its <.125 i would take this seriously on a motorcycle frame especially if its in a high stress zone which sounds like it is since it already cracked once.

it makes sense that it may be chromo because of its 7/8 diameter.

once again you cannot just weld it up with some flux core wire welder .
it can be mig welded but it is not allowed by any sanctioning body that i know of.(i would mig it if it wasnt a structural connection and i was in a jam)
finally the right way would be to have it tig welded by someone who has some experience.

 

I have had a few Arlen Ness digger front sections(half frames). I have only seen one of Arlen's complete frames in the early 1980's which was for a rigid shovelhead. They looked like sportster digger frame, very little up stretch, but with a lot of forward stretch. It was frame that Arlen made for his friend Barry Cooney aka BC Choppers in Portland ,Oregon. What Arlen made was front sections for sportster and the big twins. I think what you have is one of those front sections. The front sections for the big twins were cut a few inches above the front motor mount and severel inches in front of the seat post where the side frame rails meet (v under the seat). The sportster front section was cut a few inches forward of the splined mid control foot peg bracket mounts(3/4 of the lower frame removed) and a few inches in front of the seat post. If you look at most of these digger customs with swing arms, the factory Harley-Davidson rear half frame/ castings will be there. Arlen had Bob Munroe fabricate these frame pieces. Bob Munroe is a very well known in the Hot Rod world.
The digger frame came from the the drag racing world. Where as small size material and the materials used.
I still have a sportster frame with a front section. It is one of the last made that is a drop head frame. I have seen on other like it. The main back bone starting at the middle upper motor mount goes lower going forward to the neck set. Not up and out but down and out
Have fun.