Cutting Wheel Studs - Safe or No Way?

[89Trooper]

Please read before answering the poll!

This always seems to be such a taboo topic when it's mentioned, and I'm curious to find out why.

Due to various things (rim width, rim offset, look, etc.) I have determined that 20mm wheel spacers will look the best all the way around, and to do this, I need to cut off 3mm from the studs. If you care about the math: our studs are 30mm long, 20mm is taken up by the spacer so 10mm needs to go into the relief hole of the rim, but my rims only have 7mm of relief, hence needing to cut off the 3mm.

Before you vote, let's look at some things:

• The amount of thread engagement needed to be safe is equal to the diameter of the studs.
• Our studs are 14mm in diameter, so you need at least 14mm of thread engagement.
• Interestingly, the nuts that hold on the wheel spacers have exactly that, 14mm of thread engagement.
• Measuring with a caliper, there is at least 20mm of thread engagement using the lug nuts without wheel spacers.

So, I could cut off TWICE what I need to, and if I went back to not using spacers, there would still be enough thread engagement to be safe.

If you vote "no", I would really love to know why you wouldn't, or why you feel it would be unsafe.

Sponsored

 

[krisk]

Please read before answering the poll!

This always seems to be such a taboo topic when it's mentioned, and I'm curious to find out why.

Due to various things (rim width, rim offset, look, etc.) I have determined that 20mm wheel spacers will look the best all the way around, and to do this, I need to cut off 3mm from the studs. If you care about the math: our studs are 30mm long, 20mm is taken up by the spacer so 10mm needs to go into the relief hole of the rim, but my rims only have 7mm of relief, hence needing to cut off the 3mm.

Before you vote, let's look at some things:

• The amount of thread engagement needed to be safe is equal to the diameter of the studs.
• Our studs are 14mm in diameter, so you need at least 14mm of thread engagement.
• Interestingly, the nuts that hold on the wheel spacers have exactly that, 14mm of thread engagement.
• Measuring with a caliper, there is at least 20mm of thread engagement using the lug nuts without wheel spacers.

So, I could cut off TWICE what I need to, and if I went back to not using spacers, there would still be enough thread engagement to be safe.

If you vote "no", I would really love to know why you wouldn't, or why you feel it would be unsafe.

Why not install extended studs and use a slip on spacer? From all my research when I was looking to add spacers, a slip on spacer is the better (safer/more reliable) option.

I would hesitate in cutting the studs, personally.

 

[89Trooper]

Why not install extended studs and use a slip on spacer? From all my research when I was looking to add spacers, a slip on spacer is the better (safer/more reliable) option.

I would hesitate in cutting the studs, personally.

Thank you for the reply. Buy why? Why, when I proved it is 100% safe to cut them, do you say that a slip on spacer is safer and more reliable?

I respect your opinion, but I am looking for reasons.

 

[krisk]

Thank you for the reply. Buy why? Why, when I proved it is 100% safe to cut them, do you say that a slip on spacer is safer and more reliable?

I respect your opinion, but I am looking for reasons.

Please don’t misunderstand what I’m saying as I am not claiming to be an expert. I’m not saying your suggestion is or isn’t safe, I’m giving the results of my prior research, and that is an extended stud with slip on spacer is safer than a bolt on spacer.

I would say the main reason is the ability to check the lug nut torque. With a bolt on spacer, once you put the wheel on you have no way of checking the spacer torque. Granted, I am running spacers on my car at the track, so I check lug nut torque frequently on track days, but I’d still be a little nervous on the street not being able to check torque. Additionally, you double the chances for failure. Instead of 5 studs and nuts per wheel, now there are 10 that could break. Lastly, extended studs are made stronger (if buying the appropriate kind) than stock, again increasing reliability.

So while I’m not saying your option is unsafe, I’m saying there are safer alternatives, thus the reason I didn’t cast a vote in your poll.

 

[89Trooper]

Please don’t misunderstand what I’m saying as I am not claiming to be an expert. I’m not saying your suggestion is or isn’t safe, I’m giving the results of my prior research, and that is an extended stud with slip on spacer is safer than a bolt on spacer.

I would say the main reason is the ability to check the lug nut torque. With a bolt on spacer, once you put the wheel on you have no way of checking the spacer torque. Granted, I am running spacers on my car at the track, so I check lug nut torque frequently on track days, but I’d still be a little nervous on the street not being able to check torque. Additionally, you double the chances for failure. Instead of 5 studs and nuts per wheel, now there are 10 that could break. Lastly, extended studs are made stronger (if buying the appropriate kind) than stock, again increasing reliability.

So while I’m not saying your option is unsafe, I’m saying there are safer alternatives, thus the reason I didn’t cast a vote in your poll.

Excellent reply - thank you! Those are very good reasons to consider. I have added a third option to the poll, so you can make an honest vote.

About the torque-checking. I'm one of those nuts that often takes my wheels off to clean the inside of them. So, I would have many more opportunities to check the torque.

 

[krisk]

Excellent reply - thank you! Those are very good reasons to consider. I have added a third option to the poll, so you can make an honest vote.

About the torque-checking. I'm one of those nuts that often takes my wheels off to clean the inside of them. So, I would have many more opportunities to check the torque.

Thanks. Vote cast.

I think you likely would be fine with your suggested setup. I just view it from the standpoint of preferring to swap the studs out versus cutting them.

 

[robvas]

1-3 threads exposed is the aerospace rule

easiest to get longer studs and slip on spacers

 

[89Trooper]

1-3 threads exposed is the aerospace rule

There are plenty of exposed threads on the nuts holding the spacers.

No exposed threads on the lug nuts.

But I know what you mean - if, after cutting off 3mm, I went back to not using the spacers, I would have 1-3 threads exposed (if using regular 14mm nuts).

 

[SSuperDave]

The only way to cut them that I know of that wouldn't take you a month to Sundays is a cutoff wheel. My concern would be the heat generated by the cutoff wheel may change the temper in the studs causing them to fail prematurely. Not a metallurgist or anything but just thinking that.

 

[89Trooper]

The only way to cut them that I know of that wouldn't take you a month to Sundays is a cutoff wheel. My concern would be the heat generated by the cutoff wheel may change the temper in the studs causing them to fail prematurely. Not a metallurgist or anything but just thinking that.

Another good point, and yes, I would definitely use a cutoff wheel.

Same, about not being a metallurgist, but from what I've read, the only way to weaken a grade 8 bolt is by using an acetylene torch. A cutting wheel won't get them hot enough.

 

[89Trooper]

Three votes recently added for "unsafe" - it's easy to vote, but I would love to understand why you feel that way.

So far, the math proves it's safe... please let us know your views as to why it's unsafe.

 

[robvas]

Was watching a chassis builder on YouTube and they said the only "right" way to shorten a bolt like that is to use a lathe

why they said that, they didn't say

 

[gtstang462002]

I mean, 5mm isn't very much in terms of wheel spacing. I went with a 25mm spacers and didn't cut anything. Got the look I was after also with the wheels for the application.

 

[89Trooper]

I mean, 5mm isn't very much in terms of wheel spacing. I went with a 25mm spacers and didn't cut anything. Got the look I was after also with the wheels for the application.

Yep, with 25mm I was fine. Need to take off 3mm to use 20mm, though. It’s not much, but I can tell the difference!

No problem trimming them. Grinding was easier than cutting. Never got hot enough to cause any uses with losing strength.

I cut an old lug nut down to use as a guide. Then that cleaned up the threads when I took it off. The lugs holding the spacers screwed on no problem!

 

[gtstang462002]

Yep, with 25mm I was fine. Need to take off 3mm to use 20mm, though. It’s not much, but I can tell the difference!

No problem trimming them. Grinding was easier than cutting. Never got hot enough to cause any uses with losing strength.

I cut an old lug nut down to use as a guide. Then that cleaned up the threads when I took it off. The lugs holding the spacers screwed on no problem!

I am putting my stock wheels back on when the weather warms up also, so I didn't have a huge desire to modify my studs from that standpoint also.

Sponsored