Spoke straightening

29 model-a

29 model-a

Senior Member
Have a 29 truck that I'm restoring, I need to straighten a few spokes. Is there a way to do this with out buying the tool? Only have to do three to four spokes. Wheels need to be blasted and paint. Thanks Pete
 
I cut a small hook out of 3/8 flatstock welded a nut to it and used it on the end of a slide hammer for bodywork worked pretty good
 
I used a ball peen hammer and a bodywork dolly. Use the dolly as a backing and tap the spoke lightly with the hammer, it will move quite easily. Then use a small straight edge to check your progress.
 
So let me ask this question, ...if the spokes are bent, doesn't this mean the steel rod (spoke) has been stretched? If you bend it towards a different direction, where does the excess go? Remember, the steel rod (spoke) is not elastic.

Thought to ponder, if the steel rod (spoke) is not in tension in a straight line, then is it doing its job?

.
 
1. Rip a piece oak, ash, hard maple or other "hard" wood to about 7/8" x 7/8", & cross cut same to about 5" long.

2. In the center of one of the 5" long sides, with a table saw, handsaw, or hack saw, cut a grove 5" long, about 3/16" wide, & about 1/8" deep -- best if cut in a vee shape.

3. Position the wood tool length-ways, "under" the arched spoke where the spoke is in contact with the two (2) ends of the wood tool, & the high point of the arch is farthest away from the wood tool.

4. Place a "C" clamp such that one bearing surface is positioned on the high point of the spoke's arch, & the other bearing surface is positioned directly below on the wood.

5. Tighten the "C" clamp until the high point of the arch is pressed downwards into the grove of the wood tool.

6. To protect paint on spokes, place a 1/4" thich piece of hardwood between the clamp & the spoke or some other hard rubber material.

7. Straightening spokes may change the run-out of the rim, for which there is another method to correct this problem by heat shrinking spokes.
 
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I use a pry bar with a reverse hook on the end and pry aginst the center hub with the spoke being moved by the hook end. Any good small pry bar will do the job with a small block of wood under it also. To move the long ones sideways I use a long punch and pry against the lower short spokes. I never use a slide hammer, only prying. I find they want to go back to "home" as long as they are not "super stretched". On real bad stretched ones I have had to cut if not already broken and weld back together. Watch for crack in the hub as I have had many of those and had to weld them up again,
Ken
 
any time i have straightened any spokes i ended up with lots of wheel run-out because of the issue Brent brought up, so I stopped doing it and look for better rims
 
Brent's comment make sense. I remember an article somewhere in the past where the author would use heat on a spoke and then quench it with water to shrink it back in shape. Cannot remember where I read that good info though.
 
Mikeinnj said:
Brent's comment make sense. I remember an article somewhere in the past where the author would use heat on a spoke and then quench it with water to shrink it back in shape. Cannot remember where I read that good info though.
Click to expand...

Dave Gerold and Brent both have talked about shrinking the spoke by that method. I'm not sure where the information is, but that's the method I would use.
 
Yep. The spokes originally were under tension (pulling force, like stretching a rubber band) like bicycle wheels and sports car wheels that were tunable by tightening the nipples. If they were not under compression, the wheel would have no strength. If you think about it, you can visualize that only the upper spokes are the ones that hold the car up. There are factory promotional pictures that show a Model A hanging by one spoke (lots of tension). With wooden spokes, it's just the opposite, as they work in compression only and it's the bottom ones that hold the car up. You can determine which Model A spokes are under more tension by tapping them with a very small hammer or the back of your pocket knife to hear the pitch. The spokes with higher pitch have more tension. The "dead" spokes, those with no tension, make a dull sound and contribute nothing to the strength of the wheel; they're just along for the ride. So there are hundreds of A wheels out there that have had their spokes stretched, as Brent said, that when straightened are no stronger than if the straightened spokes were chopped out. It is relatively simple to re-tension the spokes with heat and a special fast clamping device, but tedious to get the tension the same on all of them while correcting or maintaining wobble and run-out of the rim. I believe there was an article on this subject in The Restorer about six years ago.
 
OK I can understand the issue about tension on the spokes being the way the wheels were designed and made to perform their function, but I've never heard about any detrimental issues from running wheels with untensioned (not broken) spokes. Am I missing something here?
 
Just thinking, on a straight wheel, if you hit & bend 1 spoke with a hammer & a drift, would it wobble?
If you then straighten that spoke COLD, would it still wobble, or would it wobble worse, or would it wobble the other way?? JUST THINKIN' Bill W.
 
Obviously there would be an impact but with all the wheels with untensioned spokes out there it appears to be a moot point. However it does bring up another question. The new wheels now being made, are these designed and built in the Ford manner with spoke tension and balance a consideration or are they just a cosmetic reproduction?
 
I am getting ready to measure a set of model a wheels for wheel "run-out" using a dial indicator. For those of you that have a lot of expereince in this area - what is a typical amount of run-out for what you would consider to be a wheel with no further straightening needed and what would be a typical amount of "up-down" (not sure what the proper term is) for a wheel that you would consider no further attention is needed.

Thanks - Hunter
 
BRENT in 10-uh-C said:
So let me ask this question, ...if the spokes are bent, doesn't this mean the steel rod (spoke) has been stretched? If you bend it towards a different direction, where does the excess go? Remember, the steel rod (spoke) is not elastic.

Thought to ponder, if the steel rod (spoke) is not in tension in a straight line, then is it doing its job?

.
Click to expand...

I've wondered about that, too. But the Murray Fahnestock contemporary articles talk about straightening spokes if slightly bent or if badly damaged, cutting them out and welding in new ones. Whether that was all baloney, I don't know.
 
A steam fitter that worked for me installing industrial boilers used the heat and cold quenching method to staighten and shrink pipes. He was an old German that served his apprenticeship in the shipyards in Germany. As a young Engineer, when I would hear him start talking, I would listen intently.
 
I consider 1/8" runout, and 1/8" wobble or less as good. As mentioned spokes can be straightened with heat and cooling. If you have a spoke broken at the rim, just drill a hole in the rim where the spoke was spot welded, and plug weld the spoke back in place. As the weld cools it will tighten the spoke, so it's doing it's job by being in tension.
 
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