Installing larger wheel studs (Kore3 advice)

[dcozzi]

I had hoped it was a matter of just enlarging and threading the holes but, I assume this is an extremely precise job since my machine shop will not touch it. They say I need a fabrication shop so the car will not ride like it has tires with flat spots.

What do I do now?????

Tobin.....are you out there? Can I send my hubs back to Kore3 to have this done?

[GetMore]

The job shouldn't be all that difficult. It would take some time to do the setup, but I don't see it being hard to do.
I think the difficult part of it is going to be fixturing the hub for machining.
If I was doing it I'd use the back end of a drill bit or a cylindrical piece of metal the size of the current holes, place it in the chuck and get the hub lined up with that. Then all I'd have to do is raise the chuck, swap in a larger bit, and drill the holes. Hit them with a countersink or a deburring tool to clean the edge of the holes and you're all set and ready to go!

[dcozzi]

Interestingly enough, that's what I thought too. Line it up with the same diameter bit and clamp to the drill press table. I am concerned it will not be perfect like when using a perfect fixture like the one used by the hub manufacturer.
The fear is, if it is off just a c-hair, will it harmonic at a certain speed?

[neki67]

And don't forget; the best way for wheels to be centered is to have the correct hubcentric ring in place. Do a search on hubcentric and I guess you will get your answer.

[Twentyover]

How much radial runout does a ture have? or lateral runout? I don't know, but since it's made of rubber and the ub is made of aluminum or steel, I'll suggest a tire is going to provide much more of a problem then a stud being off a couple hundredths.

On the little green race car (an MGB), I found a stud out over 1.5mm, and it wasn't TOO bad

[dcozzi]

How much radial runout does a ture have? or lateral runout? I don't know, but since it's made of rubber and the ub is made of aluminum or steel, I'll suggest a tire is going to provide much more of a problem then a stud being off a couple hundredths.

On the little green race car (an MGB), I found a stud out over 1.5mm, and it wasn't TOO bad

That's a good point. A tire is not perfectly round. Hmmmmm.....but is that compensated for by balancing the tire and rim together? Ahh, questions, questions. I think I am over-analyzing the whole thing.

I like the idea of the hub-centric ring. I will investigate. Thanks!!

[Steve68]

Remove studs, open hole for knurl on new studs, put new studs in freezer(makes for easy install) use brass drift punch to install, make sure base of stud is flush/flat with hub,

[David Pozzi]

I converted our second gen to 12mm studs with no problems. It has to be done in a drill press and you need it properly set up so the holes are straight. The studs just hammer in.
David

[Apogee]

Normally we would refixture it in the CNC mill and re-do the pattern just to be sure that everything stays in specification rather than leaving anything up to chance. Considering we've already got the fixtures to do that, it just makes sense. That said, you can usually "float" a larger drill and ream through the existing holes in a manual mill or drill press without having them move more than a couple of thousandths. The flatness of table, runnout of the spindle, cutting tools condition, etc that you use will typically have an impact on the finished product.

Tobin
KORE3