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Two years ago, I splurged and got solid chromed wheels for my 01RKC because I was tired of the spokes and tubes. The tires were new so they used them, but now they need to be replaced. Upon removing the tire from the front wheel, the valve stem accidently got broken. Apparently, Custom Chrome wheels use a smaller diameter valve stem than everybody else.

Here's the problem. I would like to have the valve stem holes drilled out, but my mechanic is concerned that the chrome will flake if it's not done properly. What is the proper way to drill the hole and save the chrome? The drilling will start from the outside of the rim (where the chrome doesn't show since it's under the tire) and go towards where the valve stem comes out on the rim (where the chrome of concern shows). What is the recommended drill bit and speed (not only in revolution, but also how fast to go into the hole)? Anybody done something like this successfully? TIA. jopez
 

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I would drill most of the way through leaving just a sliver of material and then finish removing the little lip with a diamond burr mounted in something like a moto tool. Diamond burrs and hones are the only thing I know of that cuts chrome easily.

On the other hand, if you use a new high quality drill bit and go slow breaking through the chrome shouldn't cause any problems. Even if you were to have a tiny chip at the exit hole it would be hidden under the rubber seal/washer.

You also don't want to drill that in one pass, sneak up on it with progressively larger bits so the last bit is only taking off 1/32" per side

:cheers:
 

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KKRider said:
I would drill most of the way through leaving just a sliver of material and then finish removing the little lip with a diamond burr mounted in something like a moto tool. Diamond burrs and hones are the only thing I know of that cuts chrome easily.

On the other hand, if you use a new high quality drill bit and go slow breaking through the chrome shouldn't cause any problems. Even if you were to have a tiny chip at the exit hole it would be hidden under the rubber seal/washer.

You also don't want to drill that in one pass, sneak up on it with progressively larger bits so the last bit is only taking off 1/32" per side

I would try and just file it you cant have far to go good old rat tail file should do her? meat
 

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Pay the man...

Roll the dice. Chrome over aluminum is usually a multi-step plating process so you may have a sandwich of bonding material. We build aluminum parts for an industrial application and always, always, always machine first, plate last, especially with chrome. The few times we have to drill, re-tap or modify an aluminum/chrome part we make sure we've got an extra one. The machinist always starts from the chrome side. When the bit goes through the exit hole you'll get buring and pushout that will likely peal the chrome layer. Drill a hold in wood... the ugly end is the punch through. I've seen some of our machinists very carfully etch the chrome with an abrasive bit as well, they say it's like etching glass to make it snap clean. These guys are pro's and still have to scrap parts. Of course, all 14 of our guys have their own secret.

My advice, have a chrome shop or a metal shop machinist do it. It's worth a few bucks to get it done right. It's like the first scratch on your paint. You might be the only one that notices it, but you will notice it for ever! Even if it's hidden.
 

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Harleys Nothing Compares
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You can use piloted Core Drills and Keep stepping it up -- Then use a reamer (piloted) DO NOT DRILL FROM THE INSIDE OUT -- DRILL FROM THE CHROME SIDe IN Unless you can clamp a piece of hard wood on the OUTSIDE HOLE (Chrome Part) to keep the drill from "BREAKING OUT" and chipping the chrome

Peace
Dan
 

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Use a new Cobalt drill bit. Also, use some Rapid Tap cutting oil but just to get past the chrome. Use very slow rpm. Once through the chrome don't use the cutting oil as you don't need it for aluminum. I've done this before and it works very well.
 
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