Changing the center bore

[Fullhouse]

Hi everyone, as the title says, is this possible and safe to do? I called a local shop and they said that this doing this will damage th wheels and make it weaker. They are not able to do it and referred me to another shop. The other shop they should be able to machine it for $150, but they would have to look at the wheels first.

I'm planning to change the center bore from 57.1 to 66.6. Have any of you ever done this before? Any shop to recommend in SoCal?

Thanks!

[Mops@Nemesis]

Certainly possible to do safely. I would get with some performance/race shops and let them recommend a shop that has done work for them or thier customers.

[sirmium]

i did it 2 years ago on my winter wheels, no problems so far. Here is topic about it: http://www.a5oc.com/forums/s5-perfor...nter-bore.html

It was very easy to do, took it to a friend who has CNC machine shop, it didnt take him much and he did it for free.

[mxrz]

It is entirely dependant on the wheel design. Without seeing the hub pad of the wheel in question, no one here can pretend to know the answer.

[Fullhouse]

Certainly possible to do safely. I would get with some performance/race shops and let them recommend a shop that has done work for them or thier customers.

Yes I asked a number of shops and only one said they should be able to do it but would have to look at the wheel design first. Others said that it will weaken the wheels and they wouldn't recommend me doing this.

i did it 2 years ago on my winter wheels, no problems so far. Here is topic about it: http://www.a5oc.com/forums/s5-perfor...nter-bore.html

It was very easy to do, took it to a friend who has CNC machine shop, it didnt take him much and he did it for free.

So if I understand correctly, the wheels that you mistakenly bought has 57.1 bore and your s5 is 66.6 bore? If yes, then we are in the exact same situation.

You said that they drilled out 15mm deep? What does that exactly mean? I thought they only need to modify the diameter of the bore, if that makes any sense.

It is entirely dependant on the wheel design. Without seeing the hub pad of the wheel in question, no one here can pretend to know the answer.

I'm sorry but I don't quite understand what you are trying to say here. The shop that I called also said I would have to bring the wheels in person and let him looked at it. I told him that I'm getting HRE p40, would all p40 have the same "hub pad of the wheeel"?

Thanks every one who responded!

[mxrz]

Machining a lightweight forged wheel? Damn, that's a bad idea.

[sirmium]

@fullhouse
When i said 15mm deep i meant: they re drilled 57.1 to 66.6, but didnt have to go all the way through the rim. If you look at the pictures 4,5,6 you will see what i'm taking about. Redrilling ends 15 mm inside, that part fits over the hub.

I might have a drawing that i made for machine shop, if i find it i'll post it here.

[bkw]

Contact HRE and see what your options are. I've had good experiences with them with my past wheels and they've always taken care of me.

[Mops@Nemesis]

It is entirely dependant on the wheel design. Without seeing the hub pad of the wheel in question, no one here can pretend to know the answer.

Apologies, OP. During any discussion I've had or viewed on this topic, I've not seen any warnings in regard to safety. I guess I assumed if there wasnt enough mounting surface to shave a bit then it must be a weak design to start with. I guess 9.5 mm is more than a bit.


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[seph]

Yes I asked a number of shops and only one said they should be able to do it but would have to look at the wheel design first. Others said that it will weaken the wheels and they wouldn't recommend me doing this.


So if I understand correctly, the wheels that you mistakenly bought has 57.1 bore and your s5 is 66.6 bore? If yes, then we are in the exact same situation.

You said that they drilled out 15mm deep? What does that exactly mean? I thought they only need to modify the diameter of the bore, if that makes any sense.



I'm sorry but I don't quite understand what you are trying to say here. The shop that I called also said I would have to bring the wheels in person and let him looked at it. I told him that I'm getting HRE p40, would all p40 have the same "hub pad of the wheeel"?

Thanks every one who responded!

if you mistakenly bought the wrong bore size i would call HRE and see what they can do for you. Not sure i would recommend re-boring a lightweight forged wheel as mxrz said.

[Mops@Nemesis]

It's a used set from a B7.


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[Fullhouse]

called HRE and no engineers are available to talk to me. I talked to the sales instead and he wouldn't recommend me doing it because it would cost too much to do it. He told me to wait for flow form wheels that is coming out in a few months.. typical sales tactics huh..

I guess I will wait until tomorrow to talk to the engineers to make sure they can do it.

[Blake P]

called HRE and no engineers are available to talk to me. I talked to the sales instead and he wouldn't recommend me doing it because it would cost too much to do it. He told me to wait for flow form wheels that is coming out in a few months.. typical sales tactics huh..

I guess I will wait until tomorrow to talk to the engineers to make sure they can do it.

Don't talk to the sales guys, ask for service. They do this kind of stuff all the time and service pricing IS negotiable, so don't accept the first offer you receive.