Hi Ray, while not going to say I know a lot about this, I do know the aggravation, and I am interested in your post . Engineer hat on, the metal knock off ears are symmetrical in weight around the center by design and being machined or cast, I sincerely doubt any issues there. The wire rims may be running off side to side on wires looking at them on car vertically, so you will get an indication on fancy machines of weights needed off center to fix “lateral runout” of the rim weight CG around the center point which causes a shaking force. , ---on car wires , usually welded , not sure how you can fix that. …they may have checked runout, I am sure they did, but this is subtle stuff. The rim and wire spokes have to be pretty close to ideal , direct from factory tolerances are / have to be ok, unless hit hard once. Pothole or curb…
Wire wheels are rough that way, speaking from 650 Triumph motorcycle days long ago..If you adjust those spokes (they were adjustable on Triumph ) you can get into a world of hurt , even following the book. .been there. Made it worse,. Some ended up totally loose “when wheel was running right” = Now what??? Experts on adjustable wires can “true” the wheels , bicycle guys do it too, but I do not know about truing yours if welded . A knock against a curb kills it. ( had XKE too…constant hassles with bumps causing shake )
That is different than the tire (itself) being out of balance which can be more weight on one side than the other of the tire carcass ,as well as less common side to side weight distribution issues . That off center weight around main turning axis or wheel bearing is usually what is balanced out , often by two symmetrical equal weights inside and out on light side of rim (lacking the fancy stuff) once you know how much it is out . That seems to work fine. Thinking is right. Not perfect but fine. It was all we had for many many years. Bubble type do the same thing. Pressed steel rims have to be pretty good inherently, just due to how they are made, assuming reasonable QC..they do not balance rims on new cars, they just use them as made . So “balancing” normal steel rims strikes me as a story to be explained . But maybe for 200 mph. Note that balancing will not ever fix runout…
If tires are out of balance in the “normal” way they can be, and rims are ok or a little out, balancing whole thing should be fine, or even better than each separately. Caveat, rims not out of spec. reposition tire for minimal weights if that changes ..
Sometimes one sees attempts to equalize out the rim fill hole and weight of the rubber fill parts , a small dot welded 180 away. .
You might pull all the weights, go to a simpler old style machine and put one pair where it needs it. Off axis different weights all over the place are asking for it, IMHO
So chances are very high , on pressed steel rims not damaged (check rim runout on car side to side and radially ) that it is the individual tire quality or symmetry , , which sometimes works out in balance efforts and sometimes does not. Now, add in out of round tires that show no imbalance (Cooper!!) –you are driven crazy. Out or round you can pick up by measuring runout of OD of tire on rim on car. I had a 67 Barracuda 273 where I had fought this 65 mph shaking , for a year, one day I was talking to a guy walking next to car in my driveway while rolling slowly, I noticed car is noticeably slowly moving up and down while next to him! Like 3/8” out of round ---but they had been balanced ok ! New Cooper tires. This kind of “unbalance” or quality defect also caused the lug nuts to loosen, several times. Added to that, I found out the large diameter ~10” long steel rod with nut (not the strut rod) that goes through the cross member, into the lower control arm bushing was bent (huge pothole hit, before me?), causing shaking dependent on steering angles, = angled tire wobble, and tire hitting inner fender at extreme cut of steering , when backing up . My litany of woe.
All this also assumes good piloting of brake drums and not turned off center somehow, by incompetent guy. Why I like leaving drums alone if round, even if scratched. Can do more harm than good. Brake drums are heavy. Can balance those?
While I have 4-5 pairs of American Classics, and no problems, look terrific, they took some weights, but I have almost no miles. . But not totally vibration free (watch out for letter car front U joint driveshaft vibration which can fool you and is common) . On a few cars done recently , I went back to Michelin,. In a dozen tires in past 4-5 years they have not needed any weights at all ,..so, = perfectly made tires . 2002 jeep has them 17” with relatively cheap cragar black rims from Summit. No vibration at all. Makes me very happy to drive it. 70-85 no shake!! There is something to be said for this. But black walls do not look right on a letter car, I know that, but they sure perform well. Can get rated for 150 plus.
Just the best tires….has a blackwall “patina”, like its owner….PBR and all that.
From: Chrysler300@xxxxxxxxxxxxxxx [mailto:Chrysler300@xxxxxxxxxxxxxxx] On Behalf Of Ray Melton rfmelton@xxxxxxx [Chrysler300]
Sent: Wednesday, May 09, 2018 3:09 PM
To: Lindsey; Chrysler 300 Club, Int'l
Subject: [Chrysler300] Coker tire and wire wheel balance
Hello -
My recently restored 1957 Chrysler 300C convertible has a set of new-ish wide-whitewall 235/75-15 Coker Classic tires on a set of chrome wire wheels made by Motor Wheels. The wheels are at least 40 years old, but are still in excellent condition. However, due to an extended restoration, the tires are now over 6 years old, but still have the "whiskers", having accumulated only 500 miles. I had the steering aligned and the wheels/tires balanced at a very meticulous and cooperative alignment shop using the Hunter "Road Force" equipment. I was surprised that each wheel took at least 5 ounces of weights, with one requiring 8 ounces - all over the inside and outside of the rims! The Hunter equipment showed that lateral and radial runout of the wheels and tires were within specs, but the total "roadforce" was above spec on two of the wheel/tire assemblies. The shop had already tried relocating the tires on the rims, so they said that's the best they could do; the residual roadforce was because of internal inconsistencies (stiffness and thickness) within the tire carcass.
The tires seem to flat-spot pretty significantly from sitting in the garage for a couple of weeks, and even after driving 20 miles at highway speeds, there is still noticeable wheel vibration. I took the car back to the alignment/balance shop and they ran it through the full balancing routine again (not just the plain spin-balancing typical at most tire shops), and their re-run came up with almost identical numbers. (They very generously only charged half-price for the re-run!)
This is the first time I've heard of separately balancing the rims alone, and was surprised that you found that it made a significant difference; I was under the impression that the combined wheel/tire balancing process took care of any imbalance of the rims alone. What did your shop do to balance just the rims alone? It seems like they wouldn't just put knock-on rim weights on the rim because that would probably interfere with the additional weights when the tire was installed. Maybe tape-weights on the inside of the rim that would not interfere with the knock-on weights after tire installation?
Can anyone clarify what I should ask the shop to do to have the rims balanced separately? Should I have the simulated knock-off hubcaps installed, since they are actually rather heavy and are somewhat unsymmetrical due the the knock-off "ears"? Seems like I would have to keep each hubcap dedicated to a particular wheel, and indexed somehow - maybe paint dots. And even if that's technically the right thing to do, I'm not sure the wheel mounting apparatus on the balancing machine could accommodate having the hubcap installed - as I recall, the wheel is held on with a big spin-on nut with large "ears" of its own.
Ray Melton Las Cruces, New Mexico
Do we have any new updates on the Coker 14" whitewalls that have been coming along for several years? I have had good results from my last set after having the rims balanced first. Have to check when back home, but probably well over 12,000 miles and most at highway speeds up to 95 mph. Usually 75-80 on your nice midwest interstates. I was not happy until Coker suggested getting the rims balanced. New ballgame after that.
High 80's in Winnipeg area yesterday!
Sent from my iPad
Harry,
Thanks for your updates on the F tire project.
Have you had a chance to run them at speed. How about the balancing process.
gary gettleman
I just installed American Classics and are happy so far, but have not got on the freeway yet.
Harry
