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Truing Wire Wheels

by Rod Schweiger

Note: this article does refer to several figures which were not in the original ascii file. Would anyone have a source for them?

Part 1 of 2

The Eagles, Take It Easy. 1969 approx.

Let me begin this piece by saying that this is the way I true my wire wheels not necessarily THE way to true wire wheels. It works for me, therefore, it should work for you. You can true wheels that are 13, 14, 15, 16, or 19 inches and it doesn't matter if they have 48, 60 or 72 spokes. Truing wire wheels is logical, it doesn't require tremendous skill, and only requires a few tools. It does, however, require an understanding of what you are doing.

The tools that you will need to true wire wheels are: a spoke wrench. Moss Motors sells a good one, part # 385-800 at $11.95. I found that the one I got needed the opening made bigger with a small file and this only took a minute or so. A fixture ~c hold the wheel while spinning to check for true is a great help. I make my own from an old MGB hub, brake rotor and a piece of pipe, see Fig. 1. You can also jack up the front of your MG and use the front hub for this task. You should also have a supply of spare nipples and spare Spokes, long and short appropriate to the size wheel you are working on. While it is easier to work on the wheel with the tire removed, you can replace spokes and nipples and true wheels with the tires mounted on the wheels. You will need to break the bead on the front edge of the rim (let all the air out first) by jumping on the tire to break the bead. You can then hold the tire down to expose the nipples with some small blocks of wood.

There are two types of wire wheels that you may encounter, chrome plated and painted. While chrome plated wires are the most expensive and are the most glitzy, they have a problem that the painted don't. The problem is rust. Sure, painted wires rust just as chrome wires do. But with painted wires we can use heat to free the spokes that have rusted to their respective nipple. With chrome wires the enthusiast will have to use patients and liberal amounts of penetrating oil, and still the rusted spoke may eventually need to be cut out of the wheel, thus destroying that spoke and nipple.

To free a rusted spoke on a painted wheel, heat the nipple to cherry red hot and then immediately quench with a rag soaked in cold water. When quenching, you will hear a noticeable pop that will tell you that the spoke has freed itself from the nipple. The heat process will discolor the spoke and the nipple. If the wheel is to be painted, so what? If the wheel was a chromy, the heat discoloration will have spoiled the spoke and the nipple.

If you have an unserviceable wheel of the painted variety, with some good spokes and nipples, you can use the heat method to lay in a supply of spare spokes and nipples. This is a good rainy day project.

There are probably only two reasons that you will ever have to fuss with your wire wheels. Reason one: you have broken spokes in the wheel and want to replace them. Reason two: the wheels are badly out of true and even a good balance job at the tire shop won't make them run straight. Let's begin with problem one. If you have a wire wheel handy, take a look at it while you read this, if you don't, look at Fig. 2.

All wire wheels have two length spokes. Long spokes radiate out from the hub at the point nearest where the knock-off attaches, and short ones that radiate out from the wide part of the hub nearest the brake drum. The two different length spokes each serve a different function. The short spokes control the roundness of the wheel, while the long spokes control the lateral runout of the wheel. Another way of describing what the long spokes do is to say that the long spokes can cause the wheel to wobble if they are not set right.

When spokes break it is usually the long ones, and they always break up near the hub. These spokes are not hard to replace except that to install the new spoke and thread it into the appropriate nipple will always require that you remove, one, two or sometimes three short spokes to install one new long spoke into its nipple. On painted wheels, if the spokes won't break loose use the heat method. If working with plated wheels, use penetrating oil and patience and if that won't work, cut the spoke out and replace it with a new one (you knew that those chrome wire wheels were going to be expensive when you bought them.) Coat the new spokes threads with Permatex Anti- Seize lubricant (part no. 133K) so that the next time you do that spoke it won't fight you. Of coarse you may be fussing with that spoke again. Remember, it's part of the hobby.

Once you have all the broken spokes replaced it is time to snug them up. Try to tighten up the spoke and nipple until it is the same tension as the spokes around it (ones you didn't change.) You can tell the tension of the spoke by tapping the spoke with the spoke wrench and listening to the sound. It should ring. If the sound is dull, the spoke is too loose. Try to make it sound like the adjacent spokes.

When the spokes are snugged up, it's time to test the wheel for true. Our goal it to try to get the wheel to within 1/16" to an 1/8" of true. Don't go and frustrate yourself by using a dial indicator. This job doesn't require that type of hair splitting accuracy. Set the wheel to be trued on your truing fixture (Fig. 3) or your front hub. You will need a piece of stiff wire as a pointer. Important, set the pointer to point to the inside of the rim on the folded edge where the tire seats.

Don't try to set the pointer to the outside edge (where the balance weights go.) If there is any damage to that part of the wheel and there often is, using it as the reference point will only further frustrate you.

Now spin the wheel and watch the pointer. If the wheel wobbles on a lateral plane, the outside spokes need work. If the wheel isn't round, then the short spokes need work. Start with the roundness problem. If the wheel is within a 1/16" or so, okay. If it is an 1/8" or more out it will be necessary to tighten some of the short spokes to get it round. Important, before you tighten any spokes you will need to loosen the spoke(s), that are in this case, at 90 degrees or at right angles to the spokes to be tightened. If you don't loosen before you tighten, then something is going to break. If it does don't despair, replace the broken spoke(s) (you are already good at that) and remember it's part of the hobby.

Once the wheel is round you can start working on the long spokes to make the wheel stop wobbling. Use the same technique. Loosen the spoke(s) which in this case are 180 degrees across the wheel then tighten the necessary ones to bring the wheel into true. Keep spinning the wheel and watching the pointer to see how the work is progressing. When the wheel is reasonably true, go around and tap the spokes with the spoke wrench and test the spokes for tightness. They should all have approximately the same sound. If necessary snug them up. Check again for true by spinning the wheel and checking the pointer.

When the wheel is true and the spokes are snug, look at the nipples on the inside of the wheel (the part normally covered by the tube) and make sure that your new spokes don't protrude through the nipples. They could pop your tube. If they protrude through the nipple, grind them down flush. Now you can prep the wheel for priming and painting. After painting, put a double wrap of duct tape over the nipples on the inside of the wheel to protect your tube. Finally use a thin smear of silicone seal on the inside of the hub on the ends of the spokes to keep the grease on the hub splines from running down your freshly painted wheels.

Finally, a few words on wheel balancing. It has been my experience that wire wheels are much more sensitive to wheel balance that a disk wheel. It is normal for a balance job on front wheels to last only three or four thousand miles. At that point the steering wheel may shimmy (usually at some particular speed) indicating a balance job is needed. I always had good luck with a dynamic (spin) balance. Any good tire shop can do it.

I hope this article helps you with your wire wheels. Special thanks to Bill Traill for sharing with me his insights into this subject.

Reference

Respoking Wire Wheels, Special Interest Autos #101 P.30. This issue is available from: SIA Back issues, Box 196, Bennington, Vermont 05201 for $5.00

Part 2 of 2

This month we'll take a look at the Rudge-Whitworth system of wire wheels. This design was invented over 50 years ago and the car makers in Great Britain used this same principle until 19,8; With this seemingly simple design, cars around the world have traveled countless miles in a sporting fashion. With the finishing of manufacture by Dunlop of this type of wheel, preservation is now left to classic and antique car buffs.

In order that wire wheels can continue to be used they must be maintained, repaired and kept in running condition. They come in several sizes of diameter, width, and varying numbers of spokes. For each wheel there is a nut or nipple, and each wheel has a hub and a rim. So, you can see that a 48 spoke wheel 96 separate pieces to maintain. Add to these the splined hub and outer rim, plus the driving hub or hub extension and the wheel nut or knock-off, and you have an even 100 pieces at each corner of your car to look after. And don't forget the spare.

When buying a car with wire wheels, it will behoove you to inspect the wheels for deficiencies, and when considering converting a disc wheeled TD or TF to wires, first ponder the cost of acquisition and/or repairs. It will be necessary to cough up upwards of $1700 for painted and $2100 for chromed kits (new). If you are able to obtain used parts for the conversion the cost will decline considerably. Or will it? Read on.....

Let's talk about maintenance. Once each year, for a car that is driven regularly (more often if the weather is wet or very dusty), the wheels must be removed, clean and grease applied to the splines of both wheel and hub. Use a grease that has a high silicon content or a marine waterproof type to prevent entry of water and other foreign elements. While performing this ritual of upkeep, each spoke should be inspected for looseness or over tightening. A simple way is to run a screwdriver or other metallic object around the wheel, touching each spoke in turn. A mistightened spoke can be detected by listening for any change in the ring produced by the contact of the tool on the spokes. A dull thud indicates looseness and a twangy sound, higher pitched than the others, denotes an overtightened one. Any defect in the spokes must be remedied before further use, lest deterioration of the wheel results.

At this time you should further inspect the wheels to detect any that are bent, wobbly cracked, out of round, or damaged in the splined area. Also look for cracks or distortion where the spokes or nipples come through the hubs or center rims. If any one of the spokes or nipples is pulled through, I'd recommend replacement of the defective hub or rim. There are other things to look for too.

If there is evidence of rust at the juncture of !nipple and spoke, the culprits will have to be replaced. If the splines on either the wheel or driving hubs are not sharply pointed or are badly pitted due to corrosion or wear due to looseness of the knock-of then replacement of these components is in order. Driving hubs may be repaired by a competent machine shop, but be prepared for a sizable bill. Most wheelwrights have replacement hubs for 48 and 60 spokers, and outer rims for 13", 14" and 15" wheels, and spokes of most any length. For the owners of those wheels which have been damaged, and for which there are no spare parts, expensive repair jobs are all that you can look forward to.

Looking now at the first figure on page 12, you can see the components and principle of the system. You will note that there are two points of contact that hold the wheel in a manner that will allow it to run true and without wobble. The inside (or back) taper contacts the inner part of the wheel hub, and the hub nut contacts the outside taper of the wheel. If any part of these two junctures is distorted, damaged or even dirty, the wheel cannot run true. Each surface should be cleaned thoroughly, filed or sanded if necessary, to remove all rough spots, and greased before installation. If this procedure is followed, and the wheel, after tightening, still seems to be loose you must first check that the original nuts and/or washers that hold on the brake drums are used. If ordinary nuts and/or washers are used, they may move out to where they interfere with the inner face of the wheel hub. Now, if the wheel is still loose or wobbles or rotates when you grab and apply force to it in the various directions, the improper seating of the tapers is to be checked next.

The outer taper is the culprit most of the time. As a result of over tightening, the knock-off can be bellied out to the point that it bottoms on the outer taper which can be necked down too. Any combination of these two defects can result in the same condition. Its usually easy to find a bad outer taper. Just note the gap between the knock off and the spokes. There should be a gap of about 3/32". If there is 1/16" or less, and the wheel is still loose, absolutely no further tightening should be attempted. This can only result in further deterioration of the condition. To determine which component is bad, you must first have a wheel, knock-off and driving hub known to be in good condition. Using the following methods you may determine any taper problems.

Remove the wheels and lay a suspect knock-off on the good wheel. Compare the distance between the good and suspect knock-off in relation to ;he spokes. A bad knockoff will have less clearance and may even touch the spokes of the wheel. Comparing a good knock-off to a suspect and the good wheel will determine whether or not the outer taper of the wheel is good. If these tests prove that the knock-off and outer taper are in good shape, mount the wheel to a known good hub and check for contact of the inner surface of the wheel hub and the brake drum or drum studs and/or nuts. Any contact at this point will condemn the wheel hub. Conversely, a suspect driving hub may be tested in this same manner, using a good wheel.

A bent wheel is usually easily detected by visual inspection, as is one with excessive eccentricity. By mounting a wheel to a rear hub and rotating it with a stationary object as a reference point, either of these conditions can be readily detected.

A clunk may sometimes be heard when changing directions as the car is moved, or when starting out. Assuming the wheels and hubs are in otherwise good condition, one must now suspect the driving splines are not up to snuff. Splines of both wheel and driving hub may be bad. Or the knock-offs may simply be not tight enough. Always tighten the knock-offs with the wheel off the ground. Sufficient force can be applied, and do not give them an extra whack with the car on the ground. You know what the looseness could be now, don't you?

Having removed the wheels, inspect the splines of both wheel and driving hub If they are badly pitted or rounded off in more than a couple of well-spaced areas, you know what to do. And, if you insist on repairing or respoking your own wheels and on your own, here are a few pointers:

  1. Do not attempt to straighten a bent rim by yourself. Find a good wheelwright who offers straightening service.

  2. Since a wire wheel is a precision object and is strung with equal and taut settings, in respoking one, be sure to use only new spokes and nipples. Don't take a chance on old or rusted ones as the super fine threads can pull right off on tightening the nipples.

  3. If you are leaning toward chroming, even of new spokes, forget it' Unless your spokes are specially stove-chromed there will be a residue of moisture that can lead to early spoke failure trapped under the chrome shell. Besides this, the spokes can lose up to half their strength if improperly done. Buy only commercially produced chrome spokes. Note too that stainless steel spokes have recently come on the market.

  4. Before dismantling a wheel, make sure you know how it's supposed to go back together. Save one wheel for a pattern or take a picture or make a drawing to ensure proper assembly.

  5. Cut with a pair of diagonals all spokes and remove the pieces easily.

  6. Wire brush both rim and wheel hub and inspect for cracks at the spoke or nipple holes. Sometimes minor damage can be welded. Generally cracks only.

  7. Insert all spokes and nipples loosely and inspect the assembly for correct location of all spokes.

  8. Make a tool from a 1/4" or 3/8" socket screwdriver bit. (A) Make sure the blade is of the proper thickness to fit the slot in the nipple and wide enough so a notch (B) can be cut out of the center to allow the spoke to enter the notch as the nipple is tightened.

  9. Now, screw down the nipples only just snug until about the same amount of spoke shows in each nipple. Use the valve stem hole as a starting point and snug up the first set of inner and outer spokes. Use an alternating and opposing pattern of tightening. Next do the pair exactly opposite the first. Then, it's back and forth to a pair next to the first, and so on, rotating the wheel always in the same direction while tightening.

  10. The wheel must now be set up in a jig on the bench. A jig can consist of a hub rotating on a spindle. A much easier way is to mount the wheel to the rear hub of a car. Make sure the axle and hub are not bent, of course. If a front hub were to be used, there might be too much play in the bearings to allow proper truing.

  11. Some indicators must now be set up to check the radial (up and down motion) and lateral (wobble) runouts. Place solid objects above the rim's inner and outer edges and some just to the side of each. Secure some bars, screwdrivers, or the like to the car frame, jack stands or other support so the runouts can be monitored during the tightening process. Acceptable lateral runout is only 0.025" and radial runout 0.050". Adhering to these standards will ensure that you will not encounter difficulties when the wheels are put into service.

  12. Proceed now to the final tightening. Begin as before with the first pair of inner and outer spokes and continue around until all are tight and the runouts are within tolerances. Recheck your work by tapping each spoke while listening for similarity of ring, correcting all deficiencies. Do not over tighten. Proper torque is about 30 to 40 inch pounds, or 3 to 4 foot pounds. In most cases a snug twist with palm-grip type driver will be tight enough. If you wish to use an anti-seize compound, such as Lock-tite, you must consider that the torque specs will change to some degree, so a combination of 'feel' and the right sound of each spoke will be the factors in obtaining the proper adjustment. Remember, do not over tighten'

  13. You must now remove by filing or grinding the ends of any spoke standing proud of any nipple, and replace the rubber strip over the nipples. Lacking the strip, you may use a few layers of plastic tape to protect the inner tubes from puncture.

  14. Clean the inside of the wheel hub and cover each spoke end with silicone gasket sealer, such as R.T.V., to prevent grease on the splines from traveling up the spokes. Do not get any sealer on the splines.

  15. Paint the wheel, now, using a spray can of aluminum enamel, followed in about fifteen to twenty minutes with a coat of Krylon or other clear spray. This will give the wheel that brushed" look. Any runs of the clear coating can be immediately touched up by re spraying the area with aluminum and following later with more clear.

  16. Finally, once your wheels are in perfect order they should be balanced. I recommend they be spin -done on the car. This ensures that all components, wheel, hub and knock-off are in proper equilibrium. All tires must be hand mounted or dismounted on all wire wheels.

Once properly done, by you or a professional, your wheels will carry your MG down the road, tracking as though it had been seeking, and finally found it.

Many thanks to David Evans, from whose recent articles in Import Car, much of the material in this column was obtained.


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The editor of this page is Bob Haskell.

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