First off I would like to say that your dealership probaly wouldn't like this mod. You should check with them as to the possible impact it might make on your warranty. Please read the entire post before starting this project.

15x7 +41 RPF1, and the RPF1 on a scale (both with 205/50/15 azenis). The RPF1's with azenis weight in at just over 28lbs, which is 19lbs lighter than my S-lites with Euporias which weighted in at 47lbs on the same scale.






For this work you will need the following tools/parts:

RPF1 wheels + hub rings
Jack + Jack Stands
Lug Nut Removal Tool (socket, provided tool, or tire iron)
18mm socket (OEM lower ball joint nut)
19mm socket (size of my replacement nuts, yours could differ)
Socket Wrench
Hacksaw (or any power/air tool that will cut through the bolt)
Red Loctite
(4) Metric size 12 Jam Nuts w/ a 1.50 thread pitch or (2) size 12 Full Nuts w/ a 1.50 thread pitch (see below for choice)



I'll start the how-to by explaining why there is a need for a how-to. The front lower ball joint bold and nut are to long to accomadate the RPF1 shape. In order to get around this you need to find a shorter nut, and cut off some of the bolt. Here is how I did it.

1. The location in which your wheel provider puts the weights for your wheel is very important. If they are put close to the spokes, they will not clear the brake caliper, and if the are set more towards the middle they will not clear the lower ball joint bolt/nuts. It is crucial that you speak with your wheel provider about where to place your weights due to the tight fitment of the wheel on the MCS.

2. Remove the front wheel and locate the lower ball joint nut/bolt.



3. Remove the lower ball joint nut, apply a healthy drop of loctite and tighten on the first of the jam nuts (shown below). Next apply another drop of loctite and tighten on the second of the jam nuts. Apply a drop of loctite between the two jam nuts.

3a. Using the same directions you can choose to use 1 full nut + loctite instead of the 2 jam nuts as I did. There is a discussion following this first post that might help you decide which method you want to use.



4. Start the hacksaw (or power/air tool) as close to the bottom of the lower jam nut as possible. You might have to start near the inside of the bolt depending on how the threads line up. Basically you want the blade to sit in the thread that is closest to the jam nut before you start cutting.



When finished it should look something like this:



5. Mount your wheel, and while it is in the air spin them it and take note that nothing is scraping or rubbing. Here is a picture of the clearance I had once the wheel was on:





(note that in these pictures I had applied blue loctite, I removed everything after I knew it would work, and then applied the red locktite which offers a stronger hold.)

6. Mount the rear wheel (no modification is needed for this wheel to fit), and repeat for the other side of the car.

7. Enjoy!!

Lowered on H-sport springs.








I took the car for a drive afterwards and listened for any scraping, or rubbing and didn't hear anything. I then drove to the parking lot we use for our local auto-xing and gave it a good thrashing and removed and checked the wheels for any signs of rubbing or scratching. I could not find any indication that there was any rubbing or scratching on the RPF1. This method worked for me, but I can assume no responsibility for your install, or how much butt you kick on the auto-x course after!!

 

to use jam nuts this way. They are much shorter because they are designed to be used not as the main nut, and they are very thin because they shouldn't be holding all the force for the intended application. There is also possiblity that you will deform the threads by not having as many threads to spread the load over when you torque the first nut.

That's the official policy, unofficially, looks good, but you might want to look for a thicker nut to be the primary, if there's room.

Matt

 

Thanks for the info. I bought a regular size nut just in case there was any feedback like this. I wanted to use two jam nuts mainly because I was worried about using a regular nut w/ only locktite. The single nut is a thread or two (maybe) shorter than the two jam nuts, so perhaps I could fit on a lock washer + locktite... I'll get a second opinion (no offense to the Dr. ) and then perhaps switch out one side tomorrow and see how it all fits together. I would think that the weight of the lower ball joint falls mainly on the top of the ball joint. Using the weight of the car, which pushes down on the entire assembly, I would assume that the nut doesn't take the majority of the force that is applied to the ball joint.

 

After searching 'jam nut' on google a bunch of pages show up most of which suggest a full nut + jam nut combo, but one does say the nuts can be the same size. One says the jam nut should always be on top, another says that it sould be on the bottom Yay for the internet. I talked to a mech. engineer friend and he said that with the force he thought would be applied to the lower ball joint nut, using two jam nuts wouldn't be a serious concern when it came to thread distortion. He saw the post, but is going to stop by tomorrow to look at everything and then make a final decision.

Dr.,

Considering there probably isn't enough room to mount a full nut + a lock washer, would you consider a full nut + locktite strong enough to hold (considering that the OEM nut had about 3 threads worth of nylon at the end as its 'lock')?

Also would you consider the force applied to those nuts high enough to worry about it being applied to the first jam nut, and supported by the second?

Lastly, how much force does the 2nd jam nut absorb in an application such as this?

 

For a nut that size, I'd be using RED loctite, not blue.

 

I've been considering the 15" RPF1's for my MC, but didn't realize there was a problem with the ball joint. Would there be anything wrong with just taking an angle grinder and grinding the original nut and bolt down far enough to clear, and then using some high strength loctite to hold the bolt fast? It would avoid having to source other nuts for the project.

-Keith

 

I did specify red loctite in the How-to stating that I applied the red loctite after taking the pictures, replacing the blue I had on hand.

You could do that, but you would be grinding away the nylon threading on the OEM nut, thus making it the same as any other nut you would put on. So, I would think that if you used some loctite it would be the same as replacing the nut and using loctite.

Most of the ball joint nuts I have taken on and off in the past have all been castle nuts with cotter pins, so this nut with a nylon end is something a bit different. I thought two jam nuts with red loctite would be the best solution, but after the DR.'s insight, I am consulting with a mech. eng. friend of mine and he is going to let me know the best solution (in his opinion) once he takes a look at the setup. I'll update the OP if need be first thing tomorrow afternoon.

 

what offset is this? 35 or 41? thanks in advance!!

 

First, I love the wheels.

Do we know if the nylon insert is for locking or if its a environmental barrier?

I would give Coast Fabrication a call. If you want a low profile locking nuts, I think you want this but they would know better.

 

Nice, I love Coast Fab. too and I have some reservations about the two Jam nut idea, torque/thread related.

 

+41...I made a change to the OP to reflect this, thanks for bringing it up

After careful consideration by my friend who spends a lot of his day with nuts & bolts, and their applications he has come to the conclusion that the difference between using two jam nuts + loctite, and using a full nut + loctite in this application is just splitting hairs. After considering the weight of the car on each corner (to the best of his ability) and the setup of the ball joint, and the lower A arm, he says that either method would be a safe replacement. I will edit the OP to reflect that there are two approaches, and anyone doing this mod can choose what they feel is the best approach.

I am keeping the two jam nuts as I feel it is the strongest lock possible in the space provided.

 

Why wouldn't you just drill and safety wire a single nut?

 

i was thinking the same thing, considering a 15" set of rpf-1's

 

I third that!!!

 

Well, I stopped at Fastenal today and talked to a little canadian guy with a mullet who knew more about nuts than I ever thought possible. He directed me to a full nut that would match the automotive grade (industry standard grade 8) of the OEM nut, and helped me order a M12 w/ 1.50 pitch, a very uncommon thread I guess. I will be attaching this nut with locktite, which he considered a better replacement than a nylock nut. I had talked to him about the two jam nut theory, and while he said it would probably be alright, the full nut would be the better solution, also the jam nuts only come in a grade 5, rather than the higher grade 8. Considering he was my 3rd opinion (the first being the board, the second my mech. eng friend) I have two suggestions for a full nut, which I will switch to. I will be changing the OP to reflect what I have learned.

I will consider the safety wire and look into where it could be threaded on the A arm or the lower hub assy.

The downside is that I had to order 100 nuts, the smallest size box that the vendor supplied. So if you plan on doing this mod, let me know and Ill send you out two nuts in the mail...I've got plenty to go around.

 

Old thread, I know, but I'm starting to research some new 15" wheels for my Mini, but I wonder if you can avoid doing this modification by going with the 35 offset version of the wheels? What do you think?

Also, What year is your Mini? Do you think the lug holes are big enough to fit the newer 14mm bolts?

 

I have a set of real Spoons, 16", OS45 if you're interested.

 

Those are bad *** wheels, but I want to stick with 15". Thanks.

 

I'm looking into 15" wheels, but don't want to do this mod.
What offset should I be looking for in order to clear that nut?

 

Most 15" wheels usually clear the nut. It just so happens that the RPF1 has a smaller inner diameter that requires cutting the the screw.

I had 15" 949 6ULs before, on my R53. No clearance issues.

 

Back the OP, wouldn't the heat from the wheels/brakes make the loctite useless?
I guess just keep an eye on the bolt position every now and then.

 

I don't think the balljoints are running up around 260°C where Loctite red melts. They have rubber boots on the other side, and they don't look like anything made for super high temps.

--Matt