Technical shaving tires

I posted on another thread about balance beads but I guess I should start my own and stop stealing another's thread.
So here goes, I'm trying to stop a bouncing tire thing and have balanced both fronts two times. Just to be clear this is not the death wobble thing this is the tire bouncing. This happens at about 60 MPH then smooths out. I got to looking at tire runout and can see the tire has a 3/16" low area, it starts off slowly then has a almost flat spot then works back up to the max dia.
Tires are Coker Classics, 600x16 and are about 3 years old, I don't think they were as bad when new but it never ran real smooth.
The question is, on the other thread, someone said they "shaved" his tires with a grinder and it worked out good. My plan was to use a 7" disk sander with 50grit paper leaving the tire on the car, just using the sander to spin the tire as it sands. Crazy idea? any thoughts on this? I guess if I have to buy new tires anyway, is it worth a try?
Sorry, the car is a '30 tudor with Ford axle.

 

Sure it's worth a try, but are you sure it's the tire or the wheel or a combination of both?

 

I ask because I had a couple of wheels on the front of the '40 that came from Wheels Vintique and both wheels were terribly out of round, one very badly out of round. At around 55 mph, and somewhat depending on the road surface, the front end would bounce very badly. I played with air pressures, re-clocked the tires on the wheels to no avail. Finally bought two more wheels from Summit (but they were still Wheels Vintiques!) I told the guy when I ordered them that I would check for runout before I mounted tires or painted them and if they were as messed up as the previous ones they were coming back to Summit. The new wheels were fine and solved the issue. I guess what I'm saying is that it's difficult to determine once they are mounted if it is all tire, all wheel or a combination of both.

 

That sounds doable if the grinder was fixed in a jig of some form and you rotated the tire with the car jacked up. It's really the same idea as @Baumi's just tackled from a different angle.

You would have to build an adjustment or shim the jig do achieve desired depth of rework. Another thing to consider is the tire is actually convex when not on pavement with weight so do you do one rib at a time?

Good luck...worst you could loose is a tire with issues if its the tire.

 

Not a good idea man, take a look at how a tire truing machine works to make a tire round.

 

I think you would be pissing in the wind and hoping to not get wet by taking a grinder to the tread as there is no viable way you will know if you get them round or not.
Standard procedure back when they sold a lot of recaps was "tire truing" where they chucked the wheel and tire in a machine not much unlike a modern spin wheel balancer that had a blade that shaved the tire tread as it spun. Guy I bought a Hunter wheel balancer from a while back had one for sale in his front end shop when he was closing out that was probably as old as me.
That aside, now from the old fart that spent a number of years fixing vibrations on cars for some damned picky customers in a shop that spoiled it's customers rotten.
Have you checked the runout in the wheel?
Have you turned the tire on the rim to see if you could cut down on runout?
Are you checking the runout when the tires are hot? Cold tires may have flat spots rather than excess runout.
If none of that has worked ask around for a shop that still has a tire truing machine. Probably the old tire store that has been in the same spot forever that has never been upgraded much is the one that will. Do it right, do it once and be done.
Are you anywhere close to this shop? https://www.taswheels.com/tire-truing

 

Do you happen to know where one of those might be...that is why these desperate measures get discussed.

I'll throw this up just for the reference factor...

https://www.jalopyjournal.com/forum/threads/tire-shaving-truing-service-registry.1017580/

 

Stratford CT the major tire company . I don’t think they will cut used tires though.

 

Yes that's crazy and will never work. And will probably make it worse. You need to take them to a shop that has a Hunter road force machine. That machine will tell you if it's the tire, wheel or both. Most likely it's the tire. Coker has put out some real junk and their customer service is horrible. Diamondback is the way to go.

 

That's the other catch 22...you can have a salvageable tire however...and how to fix it.

 

There was just a thread a few days ago discussing this.
They advertise on there web site for this service.
https://tires.tirerack.com/tires/Shaving Service

 

But they are radials......and radials are great and all the other things but they are still radials and look like radials.

There are good bias plys with support to back it and some have issues that are repairable. Before I buy a new set of www piecrust Firestone Bias Plys I will attempt to balance things out.

 

Did they sit in the same spot on the car for along period of time? we had bias tires on a tractor and if it sat to long in one spot the tires would have a square spot

 

Coupla details...Quoted

Tire Rack offers a tire shaving service that has been primarily used for preparing tires for competition use. This same service is used to remove tread rubber from new pairs or street tires to allow them to match the remaining tread depth of the other partially worn tires that will remain on the vehicle.

We can't accept tires at one of our locations to be shaved, they must be purchased from us and we'll ship the tire after shaving to you.

Oh well...

 

46Int.... Not crazy. I do it to all my Bonneville tires. Not with a disc but a belt sander mounted on the ground and adjustable towards the tire. I hand turn the tire back into the sander on the car. Takes a long time. Tires are perfectly round when done. 80 grit...

 

Could you take a pic of that truing set up and show us Jimmy? We won't share it with anyone else...promise...

 

I had 3-4 years on mine when I purchased my ride and I do not know the history other than the tread is still quite decent on all 4. I had it on those 4 wheel steel dollies over winter and those actually pinch the tires in 2 places...I think blocking up is the best for a seasonal store.

I tried pumping more air in and it seems better at 28psi...than 18psi...I have beads coming.

One Hamber said to pump them up till a business card just fits under the edge or something to that effect but I believe I would exceed 32psi to achieve a gap under the tread.

So many things effect how the tire acts...if I could find a shave location I could inquire...perhaps after the beads. It has been suggested to contact a flat track racing club.

 

I would also check the front shocks. A worn out shock can do strange things to a tire. On the other hand, a bad tire/wheel can wear a shock prematurely.


Phil

 

Well, the tire is still mounted on the wheel and that makes it hard to check radial run out but I did check it from the wheel lip and the low spot on the wheel is not at the low spot of the tire. If that makes sense.

 

Thanks for the tip, I would like to get a look at your set up.

 

I thought of that, the car gets run very often and this summer so it get out every weekend. What I did do was I jacked it up monday after work and checked it, left it jacked up and rechecked it Tuesday and my first post was what I found. You think sitting for 24 hrs would be enough?

 

I think it's kind of messed up also but the tires are not much good as they are. I'm not into the radial thing and I hear a company that shaves tires won't do a used tire.
I have seen some threads about the Coker tires being junk. Does Firestone really make the Firestone bias ply tires that Coker sells? are they any better? I'm not against buying new tires if they will be round.

 

I have checked the rim and as you would think, it is not perfect but the low spot on the rim is not the low spot on the tire, it also has some side to side run out.
Do you think this 3/16" flat spot is enough to make the tire bounce at 60MPH?
I only checked when the tires were cold.
I'm not too far from that tire truing company, I'll look into that.
Thanks for the ideas!

 

I sent Baumi a PM to try to get any details of how he did it, has not got back yet.
About the convex tread thing, I guess the plan would be to grind it flat That is why I was thinking the 7" sander, it has a larger surface than a 4 1/2" angle grinder ( what I think he used)
thanks

 

If I was to grind my tire flat the center would be gone...the weight of the vehicle settles the tread flat to the road.

 

I think he did it on a friends balancing machine...a luxury most of us do not have.

 

your right, I don't know if he built a jig to hold the grinder or just did it by hand. with the higher speed of the balancing machine he may get away with doing it by hand.
I sent an e-mail to the tire shaving company posted earlier, will let you know what they say.

 

I don't know if he was running the machine or actually just rotating it by hand to highlight high spots and just stop and grind and rotate and check again.

 

you may be right, he did say something like it took a long time.

 

Coker owns the molds and makes all the Firestone bias plies that you see on hot rods, there aren’t multiple producers of the same looking tire. It’s all the same tires from the same place.