Studs for a narrow body 5 lug using new URO hubs Options

[Tdskip]

Jumping off this thread Mark letting us know these are avalable I'm not sure what size stud I need to order.

My cars are all narrow body and will be using a set of 6x15 cookies.

Something like 52-57mm to allow for a spacer to help push the wheels out from the hub/inner wheel well a bit?

First wheel swap, thanks for the info and being patient while I get educated here.

[Luke M]

PMB site : https://www.pmbperformance.com/914suspension/5-Lug-Hub.html

Looks like Eric has some info at bottom of his ad.

[Tdskip]

Good morning Luke, I did see that but wanted to see what people were actually doing in practice.

Thanks for the response.

[Luke M]

I'm going to be using the later 911 hubs on my 6. What I ran into was the stock studs were too short if I added a spacer. Plus if doing Autox/track events the tech inspection would fail due to not enough stud sticking out of lug nut. I have a set of 66 mm studs that I'm going to run f/r.

[Chris914n6]

There is not enough room for a spacer of any significance. The 6" Cookies/Fuchs fit perfect naturally. If you go too long the lug nuts will bottom out.

[mepstein]

Open end steel nuts rule. (IMG:style_emoticons/default/aktion035.gif)

[targa72e]

I just added 5 lug hub to the rear of mine. I am using re-drilled front rotors. I originally ordered 38mm long studs as this was the length on the front of car with 4 lug. The 38mm (total length) were too short on the rear and did not allow for enough thread engagement for my liking. Because the rear rotor acts as a spacer between the hub and wheel you need longer studs than on the front. I ended up ordering some 50mm studs for the rear. The 38mm look like they will work fine in the front. I am using regular covered lug nuts not open and the studs are all screw in, no spacers.

john

[Tdskip]

So stock 45-50mm studs should be OK then with cookies.

Will give those an order and report back (but may be a month or so).

Thanks for the information sharing and all of the responses.

[Olympic 914]

Not running cookies, but I have 45 mm studs and on the 5 bolt Fuchs (951) only two threads show outside the open steel lug nuts. Front and back.

So you may want to look for something like the 50mm + studs.

I just installed 49mm bullet nose studs on the rear because my tire was slightly rubbing on the inside wheel well and I added 2mm spacers to eliminate that problem.

Got them from PMB but they are Sway-A-Way studs.

Got bullet nosed studs for the front also, but haven't installed them yet.

[infraredcalvin]

@Tdskip I've got all that if you need to borrow for trial fits... including drilled 5 lug hubs...

[bdstone914]

@Tdskip
I can lend you the tools to pull in the studs or do it for you.

[flat4guy]

A friend just ordered the complete 5 lug conversion - good looking kit - at least on the work bench. (IMG:style_emoticons/default/smile.gif)

[djway]

I ordered and paid for the hubs a while back.
Apparently there is an issue with the hub expanding after the stud is installed which interferes with the installation of the rotor.
Still waiting to hear something.

[Tdskip]

Thanks for the offers to help.

@infraredcalvin - let’s connect this weekend, I’ll drive up. Keen to see your new car!

@bdstone914 - thank you.

[UROpartsman]

Apparently there is an issue with the hub expanding after the stud is installed which interferes with the installation of the rotor.

It turns out the shoulder of currently-sold Verbus wheel studs is slightly larger diameter than OE studs (which are what we used during development), which displaces a few thousandths of an inch of hub flange metal.

The issue was noticed about a week after the hubs were released. We hadn't sold very many hubs at that point, and contacted our US customers to have them returned so we could turn down the flange OD to compensate. All of our inventory has received this minor modification, and all hubs being returned will receive it. Any hubs that were shipped to Europe are being scrapped and replaced, given the cost of return shipping. (Which is a shame because the issue can be corrected in about 60 seconds with a hand grinder at the stud locations, but we certainly can't ask folks to do that.)

At this point, the issue has been completely resolved. If there happens to be any hubs in the wild that weren't returned, just let us know and we'll get you taken care of. Hubs that have been modified have some cutting oil on them, unmodified hubs are dry.

[Tdskip]

Apparently there is an issue with the hub expanding after the stud is installed which interferes with the installation of the rotor.

It turns out the shoulder of currently-sold Verbus wheel studs is slightly larger diameter than OE studs (which are what we used during development), which displaces a few thousandths of an inch of hub flange metal.

The issue was noticed about a week after the hubs were released. We hadn't sold very many hubs at that point, and contacted our US customers to have them returned so we could turn down the flange OD to compensate. All of our inventory has received this minor modification, and all hubs being returned will receive it. Any hubs that were shipped to Europe are being scrapped and replaced, given the cost of return shipping. (Which is a shame because the issue can be corrected in about 60 seconds with a hand grinder at the stud locations, but we certainly can't ask folks to do that.)

At this point, the issue has been completely resolved. If there happens to be any hubs in the wild that weren't returned, just let us know and we'll get you taken care of. Hubs that have been modified have some cutting oil on them, unmodified hubs are dry.

Thank you for standing by your product.

[djway]

Apparently there is an issue with the hub expanding after the stud is installed which interferes with the installation of the rotor.

It turns out the shoulder of currently-sold Verbus wheel studs is slightly larger diameter than OE studs (which are what we used during development), which displaces a few thousandths of an inch of hub flange metal.

The issue was noticed about a week after the hubs were released. We hadn't sold very many hubs at that point, and contacted our US customers to have them returned so we could turn down the flange OD to compensate. All of our inventory has received this minor modification, and all hubs being returned will receive it. Any hubs that were shipped to Europe are being scrapped and replaced, given the cost of return shipping. (Which is a shame because the issue can be corrected in about 60 seconds with a hand grinder at the stud locations, but we certainly can't ask folks to do that.)

At this point, the issue has been completely resolved. If there happens to be any hubs in the wild that weren't returned, just let us know and we'll get you taken care of. Hubs that have been modified have some cutting oil on them, unmodified hubs are dry.

I purchased mine from PMB. Hopefully I will receive them soon.

[bdstone914]

@UROpartsman
@djway

I do not find your solution to be a correct or sound. The rotor locates and centers on the OD of the hub. reducing the OD can cause the rotor to be off center and vibrate.
Nor do I believe that oversize studs will cause distortion in a properly made hub.
I have installed dozens of studs of various brands and have never seen one distort. The stud splines will get shaved down if the fit it too tight. See attached pictures.

I have installed the studs in converted rear hubs which have less material than the OEM hubs and your reproductions.
My belief if that the material you are using is not as strong as the OEM material.
Care to share the Rockwell hardness, alloy used and yield strength of OEM to your material?
1. If the material is giving when a stud is install how is it going to hold up under high axial load?
2. Any testing to show the strength of your hubs vs OEM or Dansk?
Does this problem affect the 911 hubs also?
3. Which rotors are the hubs made to accept? The 914 rotors have a different pattern for the two holes for 6mm the attaching screws. The 914-6 rotors are mm larger in OD and can hit the stock 914 caliper web. If you drilled both patterns either rotor could be used.
4. Here is a product improvement idea. Make the 914 rotors with the centering feature as used in 1974 and later 911 rear hubs. It is a known problem that the lug centric OEM hubs can cause wheel vibration. Those are the desired hubs for a 914 conversion but require a spacer on the shaft to locate the hub correctly due to the taller bearing used with those hubs.

I as looking forward to getting a set of these hubs but your approach to fixing a problem is scary.

@superhawk996
Your input is welcome.

@914sixer

[Superhawk996]

I’m going to be reserved in my response because I’m really glad to see someone stepping up to make new hubs. Especially 5 lug hubs that can work with stock axles and CV’s.

As someone that has designed and released hubs as a day job, I will say that deformation of hubs after installing studs is an age old problem and doesn’t necessarily reflect on the quality of the steel or the design.

Modern hubs (which these are not)now have the hub and rotor to the stud interface surface separated by a recessed groove where the studs are. This is to allow for some axial deformation when the studs are pressed in.

The best hubs are then machined again after the studs are installed to ensure there is virtually no lateral run out from any distortion caused by pressing of the studs.

Since I don’t have a set of these URO hubs in hand yet, I can’t speak to the radial runout. However, Modern rotors don’t pilot off the OD of the hub so there wouldn’t normally be any particular concern for radial runout other than how it might affect balance. Matching the OD after pressing the studs seems prudent in this case.

I can’t speak to material spec other than to say that URO like any other aftermarket supplier is obligated for the parts they produce. I’ll assume they have done proper validation of their materials and have run some fatigue cycle tests to ensure what they produce doesn’t result in wheels departing vehicles. In a modern world that sort of liability is huge.

I do love the idea of producing a truly hub centric design. Wouldn’t that be awesome? (IMG:style_emoticons/default/piratenanner.gif) I also get that from a liability standpoint it is much safer to simply reproduce an OEM part so may not want to get too far from OEM design initially.

I ordered a set of these. I can’t wait to see them in person. Can better compare and comment at that time.

[Lanner]

However, Modern rotors don’t pilot off the OD of the hub so there wouldn’t normally be any particular concern for radial runout other than how it might affect balance.

Haven't worked on too many Porsches huh? (IMG:style_emoticons/default/biggrin.gif)

I think the issue with the first run was the counterbore diameter. It was tight for the head of the stud hence the issue. I don't believe the issue was with the spline diameter. (IMG:style_emoticons/default/confused24.gif)