Who has them and what do you think? It's coming up to Winter wheel time and if I'm going to put in studs, I'd put them in when I swap wheels. I hate using the bolts but I could always just get a wheel hanger to make the swaps easier. Just wasn't sure if the studs would be a good idea instead. I thought I remembered some track day events not letting you run without studs but I could be wrong. If you think it's a good idea, any recommendations on what studs and nuts to go with? I'm not running spacers or anything like that. Thanks guys.
Tell me about wheel studs
- Thread starter KevinC39
- Start date
Any steel stud kit will do, no sense in overkill, personally I prefer extended and rounded, requiring a double nut to tighten.
https://www.hpashop.com/TC-Kline-Racing-14mm-NASCAR-Style-Stud-for-BMW-F30-TCK-14mm-F30-studs.htm
https://www.hpashop.com/TC-Kline-Racing-14mm-NASCAR-Style-Stud-for-BMW-F30-TCK-14mm-F30-studs.htm
Wheel studs sure do make changing wheels MUCH nicer! You want to buy a stud that has a flat seat on it like what I circled in blue. This is so the stud bottoms without the threads from the hub digging in where the threads on the stud stop. A stud where the threads just end with no seat like I circled in red are bad. What happens is when you install them the threads of the hub will dig into the stud at the last thread since there is no "seat". This creates what is called a stress riser where eventually this spot will start to crack and the stud can break.
As for installation, you will want to install with a high strength and high heat loctite. Since your brakes can get very hot this heat will transfer to the wheel hub and degrade a non high heat loctite. I recommend loctite 272. Here is the data sheet for it: Loctite 272
When you install the wheel studs make sure the hub threads are very clean. Put a small dab of loctite in the hub threads and on the studs. This ensures the loctite disperses across all the threads. Also you do not need to torque the studs into the hub. Just thread them in by hand until they bottom. If you torque the studs into place, the torque gets negated by the stretch of the bolt when you torque the lug nut down.
Hope this helps!
As for installation, you will want to install with a high strength and high heat loctite. Since your brakes can get very hot this heat will transfer to the wheel hub and degrade a non high heat loctite. I recommend loctite 272. Here is the data sheet for it: Loctite 272
When you install the wheel studs make sure the hub threads are very clean. Put a small dab of loctite in the hub threads and on the studs. This ensures the loctite disperses across all the threads. Also you do not need to torque the studs into the hub. Just thread them in by hand until they bottom. If you torque the studs into place, the torque gets negated by the stretch of the bolt when you torque the lug nut down.
Hope this helps!
Thanks Barry. I wouldn't have thought to look for the flat seat but it makes sense. A lot of them out there don't seem to have that or at least it's unclear from the pictures/description so thanks for the heads up. Looks like something 12x1.5 in a 75-82mm length should be fine since I'm not running spacers? Is the hex head vs bullet nose just a personal preference type thing?
It looks like the Apex studs or Bimmerworld Race studs would fit the bill even though it's twice the price of the Apex ones. Rogue Engineering has some but they've got a rainbow colored finish on the nose that I don't care for. Macht Schnell studs were tough to tell if they had the flat seat.
Anyways, just me thinking out loud and looking over some of the options out there.
Apex Studs
Bimmerworld Studs
Rogue Studs
Macht Schnell Studs
It looks like the Apex studs or Bimmerworld Race studs would fit the bill even though it's twice the price of the Apex ones. Rogue Engineering has some but they've got a rainbow colored finish on the nose that I don't care for. Macht Schnell studs were tough to tell if they had the flat seat.
Anyways, just me thinking out loud and looking over some of the options out there.
Apex Studs
Bimmerworld Studs
Rogue Studs
Macht Schnell Studs
I'm not sure on that either. Some of them were suggesting replacement every 15hrs of track time or so. I doubt my car will ever see more than an autocross or drag strip test and tune night and not a legit road course but it will see snow and salt.
Wheel studs are a great idea. Use the strongest thread lock, or they will back out very quickly. Treat them as a wear item because they can back out, corrode, or generally wear out, pretty quick. I say that because I have been through multiple sets over the 10's of thousands of miles. Unfortunately, I haven't found that more expensive sets last longer. So far they seem to all come from the same place.
Don't let that discourage you. I still think it's a good idea, and if you find some really good ones, let us know.
Don't let that discourage you. I still think it's a good idea, and if you find some really good ones, let us know.
75mm - 82mm should be enough if you are not using wheel spacers. Definitely double check the thickness of your wheels first to make sure though. As for the bullet or hex head, it doesn't really matter. As I said above, you don't need to torque the wheel studs to the hub. You just thread them in by hand until they bottom on the seat and leave them (with the loctite of course). However, if your wheel hubs have some age the threads may have some corrosion build up making it hard to spin the studs in by hand. The hex head version helps with this for install. You really want to clean up the hub threads though so that the loctite has clean threads to bond to which negates the need for the hex head version.
As for removal, you will need to very lightly torch the base of the stud where it goes into the hub to "melt" the loctite. Then jam two nuts together and use an impact on the top nut to remove the stud. The hex head versions with the 5 or 6mm hole will round out WAY before you can apply enough torque to remove the stud.
It all has to do with "stress risers". A stress riser is anything that disrupts the grain flow of the material and/or path of the load on the material, usually some sort of gouge or corrosion. Bolt threads are rolled to make the threads strong as the grain structure of the metal flows around the thread roots. If you cut a thread (on a lathe or a die for example) then you disrupt the grain flow and create a stress riser at the base of the thread and that is where cracks start to form. This means NEVER NEVER clean up a rolled thread bolt with a die as you introduce gouges at the base of the thread. That bolt will surely fail prematurely if in a stressed environment like a wheel stud.
Side note... You will also notice on the head of any bolt there is a small radius where it meets the shank. This allows the stress to flow from the shank to the head of the bolt. If the transition was a sharp 90 degree, that becomes like a gouge and is a stress riser.
So to the point... The reason why wheel studs are considered a wear item is people that use them are usually taking their wheels on and off a lot. The repeated R&R of the lug nuts wears away the coating on the stud which allows the stud to start surface rusting which causes a stress riser. Also, most people use an impact on lug nuts and that is not easy on the threads. If there is any grime on the thread of the stud as you remove or reinstall it, that can dig into the thread root and cause a stress riser. In other words, its not about the stud, its about the frequency of the R&R of the hardware in general. You should replace wheel bolts, too, if you are taking your wheels on and off a lot.
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