How can I check my frame is straight

[Chris Parrish]

Hi, I am fixing up a 48 Chief that was in an accident and wanted to check the frame is straight, is there a set of blueprints I can download with measurements or a book with the info, or a better option I haven't thought of.

Thanks
Chris

[TH47Indy]

Hey Chris,

From what I've been told by Indian restoration experts and from info from this forum, most or all Indian frames need straightening even if they haven't been in an accident.

I believe that the only true way to check is in a frame jig. With my '47 frame and forks I did a number of measurements and checked angles before I brought it the the frame expert and thought it was pretty straight but was shocked to see how far things off once it was in the jig.

There's a lot of great people and info on this site that will help you with your repair of your '48.

Good luck and post some pictures of your progress.

Terry

[Chris Parrish]

Thanks for your quick and insightful reply Terry, now I guess I will have to track down someone who has a jig and frame knowledge.

[Chris Haynes]

http://www.wascoframe.com/ has some real nitpickers working there. The will find anything that needs attention.

[rms337]

My Indian frames are with John Bivens in California. He came highly referenced and is well known.

[Green Indian]

My Indian frames are with John Bivens in California. He came highly referenced and is well known.

Agreed, John's the guy for Indian frames. He's done two of my motorcycles and has a third in his shop at present. I'm in PA so I have to ship it clear across the county to him, but the trouble is well worth it for the final result.

[T. Cotten]

Folks,

The inspection method detailed in H-D service manuals can be adapted to other marques, with appropriate straight edges and common sense.

This Hen was fun.

....Cotten
PS: I finally found the 340 print courtesy of http://virtualindian.org/
It still will not tell you if a frame is "straight", or not...

[Chris Parrish]

Thanks Cotton,
That looks pretty easy, I'll give it a shot and see how it goes.

Chris

[tfburke3]

Indian frames are often bent in the plunger area.
One check is to assemble the plungers,put straight zerks in the nuts to get an easy center and measure center to center for parallel.
Tom

[exeric]

I love your frame table, Tom. . .

[T. Cotten]

Thank you, Eric!

Its self-leveling.

....Cotten

[Chris Haynes]

Folks,

The inspection method detailed in H-D service manuals can be adapted to other marques, with appropriate straight edges and common sense.

This Hen was fun.

....Cotten
PS: I finally found the 340 print courtesy of http://virtualindian.org/
It still will not tell you if a frame is "straight", or not...

Looks like your "Frame Table" has a little sag. :-)

[T. Cotten]

That's how it leveled out, Chris!

Actually Folks, my "frame table" is the big I beam, used creatively in the rear of the Hen.

Most frames retain their "memory", and want to be massaged square and true.
As long as the rear wheel follows the front, it doesn't matter much in between.

Framework is very satisfying.

....Cotten

[T. Cotten]

Folks, If I can really help at all..

The whole gist of the HD manuals' procedure is easy to miss.

Basically, a long straight-edge rod must be installed into the headstock. Math lets you correct for diameter, as it will for the centerline straightedge.

Then, a vertical support is set up on the rear of the frame, with appropriate diameter, so that it will guide another long straightedge rod parallel to the centerline of the powerplant-bearing chassis, usually held against the seatpost tube, hopefully spaced out enough from the headstock rod that it "sweeps" with a visible clearance, when moved in an arc.

A changing gap indicates the headstock is skewed from the chassis centerline.

Hope that helps the H-D Service manual make sense...


....Cotten

[exeric]

Most frames retain their "memory", and want to be massaged square and true.
As long as the rear wheel follows the front, it doesn't matter much in between.

Framework is very satisfying.

....Cotten

I agree 100%, Tom. Every motorcycle frame I have had, and had the awareness to check, has been mangled, bent, or just tweeked, but still out of spec. I agree that frames seem to have a memory, and are partial to returning to their original shape. However, both of my Hendersons had traumatic damage, and from my forensic research; they had been seriously hit in the right rear. It's remarkable how much stress is transferred to the (seemingly) undamaged areas.