A Spare Tire That Fits Under the Load Floor

[Frenzal]

There is surely a lug nut that would fit, no?
Because for me, this can be a problem:
1- Not having the wheel secure enough when on the car because using the wrong lug nuts on it;
2- Risking deforming part of the wheel so it might be stuck on the car when you want to remove it (stud/hub damage possible).

Also, it is important to secure the wheel in the trunk so it won't fly in the car in case of a big crash. For this, you can see what I did in the other spare tire thread (in the type S section), or drill your trunk as suggested here.

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[Nickp15]

There is surely a lug nut that would fit, no?
Because for me, this can be a problem:
1- Not having the wheel secure enough when on the car because using the wrong lug nuts on it;
2- Risking deforming part of the wheel so it might be stuck on the car when you want to remove it (stud/hub damage possible).

Also, it is important to secure the wheel in the trunk so it won't fly in the car in case of a big crash. For this, you can see what I did in the other spare tire thread (in the type S section), or drill your trunk as suggested here.

I know I'll eventually end up drilling the trunk for the mounting bracket. It's the most "OEM" looking solution to me, and I like that.

But yeah im a bit intimidated by the aspect of widening the wheels. I don't have access to a shop nor the know-how. But surely the answer can't be as simple as finding the right lugs? That would be way too easy

 

[Integra23]

Hey man thank you so much for taking the time to help us all out. Quick question. I think you mentioned somewhere these wheels were intended for a certain BMW? If so, wouldn't the lugs for that model work for us?

I believe it's for a mini Cooper

 

[RamVA]

Hey man thank you so much for taking the time to help us all out. Quick question. I think you mentioned somewhere these wheels were intended for a certain BMW? If so, wouldn't the lugs for that model work for us?

BMW uses lug bolts, not lug nuts, so I guess no joy down that path.

 

[Nickp15]

BMW uses lug bolts, not lug nuts, so I guess no joy down that path.

B

I believe it's for a mini Cooper

Do you know which gen? Am I wrong to assume the stock lug nuts for that model should work? If so, that seems like a much easier path. But my small lizard brain might be missing something...

 

[RamVA]

B

Do you know which gen? Am I wrong to assume the stock lug nuts for that model should work? If so, that seems like a much easier path. But my small lizard brain might be missing something...

As far as I can tell every generation of modern Mini and all modern BMWs use lug BOLTS, as with most/all German cars. So there will not be a suitable lug NUT from BMW.

 

[kjechel]

As far as I can tell every generation of modern Mini and all modern BMWs use lug BOLTS, as with most/all German cars. So there will not be a suitable lug NUT from BMW.

Yes, this is absolutely correct. Sorry to stir up so much worry on this subject - It's not as bad as I may have made it sound. The #1 takeaway is DON'T JUST PUT THIS WHEEL ON WITH YOUR OEM LUG NUTS AND TORQUE THEM TO 80+ FT-LBS - THE WHEEL MAY GET STUCK ON THE STUDS.

So here's the problem: The BMW lug bolts are 12mm and the surface that seats against the wheel (at a 60 degree angle) narrows all the way down to 12mm at the bottom. So the lug nut seats on the wheel are quite small in diameter. Our ITS wheel studs are M14 x 1.5, so the narrow part of standard M14 x 1.5 60 degree conical lug nuts are too big in diameter to fit into those small lug nut seats.

Here's a "solution" that didn't work: So why not just get M12 x 1.5 lug nuts and tap them out to M14 x 1.5, or machine down the conical surface of M14 x 1.5 lug nuts to the diameter of M12 x 1.5 lug nuts. I chose the latter. Here's what happened when I torqued them to 80 ft-lbs:

These are before (L) and after installation (R). You can see the nut on the right has a groove near the top and is squeezed down above that, causing the threads inside to be pinched down against the stud. That made them hard to remove. Thankfully the studs had plenty of anti-sieze on them. This happened because at the pointy end of the lug nuts (where it engages in the seat) the material is just too thin and deforms (shrinks) as it is forced down into the cone of the seat.

Next I tried using M14 x 1.5 Flange Nuts that are flat on the back, as explained in my earlier post. All seemed fine with this solution until the torque got above 50 to 60 ft-lbs. I sensed a little too much rotation for too little increase in torque, indicating something was deforming (if you've ever broken a bolt or stud while tightening, you know this feeling). So I decided to remove and inspect, and found one of the holes in the wheel had begun to deform around the wheel stud. Imagine if I hadn't stopped then to inspect - That would be bad.

So if you take this path, be sure to ADD SOME EXTRA CLEARANCE in those holes, torque the nuts carefully and progressively and remove and inspect as you increase the torque incrementally. I was able to successfully and repeatedly torque the M14 x 1.5 Flange Nuts to 70 ft-lbs, but above that I was concerned about additional deformation of the wheel. Here's what the lug nut seats look like after installing the Flange Nuts:

So next I tried what I probably should have started with - Using the OEM spherical seat lug nuts. Using the same procedure described above, I torqued these to 70+ ft-lbs without additional problems. Since I had already pre-flattened the lug nut seats with the Flange Nuts and opened up the clearance on the holes, this went pretty smoothly. But if you are starting with "virgin" wheels, I'd imagine that you may experience similar distortion in the lug nut seat area and tightening of the holes that I did when installing the Flange Nuts. So my advice is to be sure to ADD SOME EXTRA CLEARANCE in those holes, torque the nuts carefully and progressively and remove and inspect as you increase the torque incrementally. Let us know how it worked for you. I will continue to monitor this thread and answer additional questions and concerns as best I can.

 

[kjechel]

There is surely a lug nut that would fit, no?
Because for me, this can be a problem:
1- Not having the wheel secure enough when on the car because using the wrong lug nuts on it;
2- Risking deforming part of the wheel so it might be stuck on the car when you want to remove it (stud/hub damage possible).

Yes, legitimate concerns. Hopefully my post above addressed them to some extent.

Re: #1 Be sure to use a hub centric ring to center the wheel properly, so you are not counting on the wheel studs to do that. IMO (as a degreed mechanical engineer) any nut that provides adequate clamping force and doesn't come loose should work.

Re: #2 That's why you proceed cautiously when torqueing for the first time. Subsequent installation at the same torque should cause no additional deformation.

And any time you install a spare tire & wheel, it's advisable to check / retorque the lug nuts after driving the first few miles.

 

[Compromise]

So next I tried what I probably should have started with - Using the OEM spherical seat lug nuts. Using the same procedure described above, I torqued these to 70+ ft-lbs without additional problems. Since I had already pre-flattened the lug nut seats with the Flange Nuts and opened up the clearance on the holes, this went pretty smoothly. But if you are starting with "virgin" wheels, I'd imagine that you may experience similar distortion in the lug nut seat area and tightening of the holes that I did when installing the Flange Nuts. So my advice is to be sure to ADD SOME EXTRA CLEARANCE in those holes, torque the nuts carefully and progressively and remove and inspect as you increase the torque incrementally. Let us know how it worked for you. I will continue to monitor this thread and answer additional questions and concerns as best I can.

Darn, seems like a bit of a hassle. I forget that European cars use lug bolts, and not nuts. Looking at your two lengthy posts, looks like widening the holes is necessary? I was hoping I could just apply anti-sieze, and then torque some spherical lugs incrementally.

 

[kjechel]

Darn, seems like a bit of a hassle. I forget that European cars use lug bolts, and not nuts. Looking at your two lengthy posts, looks like widening the holes is necessary? I was hoping I could just apply anti-sieze, and then torque some spherical lugs incrementally.

As delivered, the holes in the wheel are just barely big enough to allow 14mm studs to fit through. Any distortion risks locking the wheel on the studs - a big problem. Opening up the holes is easy with a step drill.

 

[Compromise]

As delivered, the holes in the wheel are just barely big enough to allow 14mm studs to fit through. Any distortion risks locking the wheel on the studs - a big problem. Opening up the holes is easy with a step drill.

I'll give it a shot haha. Thanks

 

[eric123406109]

As delivered, the holes in the wheel are just barely big enough to allow 14mm studs to fit through. Any distortion risks locking the wheel on the studs - a big problem. Opening up the holes is easy with a step drill.

Thanks for a great write up and some great advice.

I understand your iterative, tighten, deform, check, re-drill process.

If I were being just a bit lazy, would you believe that it’s simplest to just open up the holes to 5/8” and be done?

 

[kjechel]

Thanks for a great write up and some great advice.

I understand your iterative, tighten, deform, check, re-drill process.

If I were being just a bit lazy, would you believe that it’s simplest to just open up the holes to 5/8” and be done?

If you do, be sure to have the wheel mounted with the hub centric ring before you start tightening. Personally, I'd like to preserve as much of the lug nut seat material as possible, but your "shortcut" might be OK.

 

[Frenzal]

I think I like my RL spare more, even if the trunk tray is not flush...

More confident with better mounting to the car and being sure to not break anything.

 

[Nickp15]

I think I like my RL spare more, even if the trunk tray is not flush...

More confident with better mounting to the car and being sure to not break anything.

Got links for the rims and tires you used?
Have you been able to test how the stock lugs press against the rims?

I apologize if you mentioned already brother

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