Anyone running the thick hubbed BBS 3pc mesh wheels???

[geof33]

I just bought a set of fronts and rears. I need 25mm spacers for the back, but none for the front. These center hubs are THICK. I don't know how to properly measure the studs to get the right length. Currently the studs are not long enough to protrude from the outer part of the hole, and I don't know how much they need to protrude for a correct length for lug nuts.

Also, for track purposes, is it recommended to use through nuts or will the alloy stock type nut work? THANKS

[geof33]

Here is a pic...

[RaceProEngineer]

Hi, Geof,

Those magnesium centered BBS wheels require a "sleeved lug nut" - they should have come with the wheels. If they did not, Jamie at BBS can sell you a set 770-967-9848. These wheels are NOT hub-centric (like the BBS RS style wheels). Therefore, they require the specific "lug centering" nuts.

As a side note, we would NEVER use a "closed end" lug nut for any track application.

Best,
Ed LoPresti
RacePro Engineering

[geof33]

Ed,

Sent you a PM... What is the proper way of determining the correct stud length?

Thanks,

Geof

[RaceProEngineer]

Hello again, Geof,

I have had another look at the digital images you posted above, but can not make out any serial numbers on the back side of the wheel center. There should be a seven digit number on one of the "spokes" (a four digit number if they are quite old.)

These LOOK like the 20-bolt wheels which many of us use for racing. If so, the outers are aluminum, but the centers are magnesium. We typically prefer slightly longer wheel studs for racing, but your stock ones will work just fine with these, PROVIDED you use the specific "sleeved lug nuts" which should have come with the wheels. These "nuts" are really threaded tubes with a 7/8" nut on the end. The tubes thread themselves over your standard studs, inserting themselves inside the lug holes in the wheels, and taking up the additional diameter in each lug hole. VERY strong - minimum flex!

Hope this helps.
Ed

[geof33]

Ed,

I'm not sure if the rear studs will work as I need a 25mm spacer for the back...

But, I need to be certain I'm understanding you. If the stud is flush with the end of the whole, then the inserts are ok, even though there will be no stud protruding from the nut. Do you by any chance have a pic? Sorry to sound stupid on this. Just trying to make sure I have the right setup...

Also, the centers have been powder coated would that cover the number you mentioned?

Thanks,

Geof

[Kevin Stewart]

25mm is one inch you need a wheel adapter or turbo spacers and new studs, Kevin

[GeorgeK]

Ed, Geoff,
Not all these Mg centered BBS rims need a specific lug nut. I have a set that takes the std Porsche spherical nuts.
Geoff, do you have a close-up of one cleaned lug nut area?

[geof33]

George,

The holes I can tell you are the same diameter as the holes on my fuchs. In other words, there is not rotational slop (a little as normal) but not enough to accomodate that lug insert in the foto. I'll double check that though, and repost...

[RaceProEngineer]

Geof,

You are not sounding stupid IN ANY WAY - I am simply not explaining it very well! Bear with me while I try again.

"If the stud is flush with the end of the whole [hole], then the inserts are ok, even though there will be no stud protruding from the nut." YES! If these BBS wheels are like ours (and they certainly APPEAR to be), the proper lug "nut" is a threaded tube, about one and one-half inchs long, with a 7/8" bolt on one end, all one piece. The threads fit the standard Porsche lugs. The tube portion threads over the stud, and fits down inside the bolt hole in the wheel center. In other words, one has ~ one and one-half inches of thread connection on each lug.

These BBS racing wheels do not have a sleeve or other connector which mates to the Porsche hub, like the Fuchs do (hub-centric). Therefore, one needs some other method of ABSOLUTELY locating their position on the hub. This is accomplished with these special "lug nuts" removing that "slack" of which you speak.

Power coating, especially if there is more than one layer, could certainly obliterate the serial number.

We are unaware of any of the BBS 20-bolt racing wheels which do not require the special “lug nuts” to work CORRECTLY on a 911, except the center-lock design. Once again, I would defer to Jamie at BBS.

Also, I do not know how I missed your original comment about requiring a 25mm spacer on the rear. Inside and outside “halves” for these wheels are readily available in half-inch increments, so before investing in spacers ( which are ALWAYS a compromise, elpecially on a track car!), you might check into re-configuring them with the correct backspace.

Again, we hope this helps.
Ed

[geof33]

Ed,

BBS no longer has the through studs... Do you have any? They have replaced them with the insert as shown above.

With regard to the wheel halves, I've tried to find out what the offset/backspacing needs to be for RSR flares and get what was necessary. Do you know what it is?

Thanks.

[GeorgeK]

Geoff, a few remarks/questions:

Is there *anything* in the lug recesses on your rims? I think there must be some insert, no matter what type of lug nuts you use. I don't think the Mg alloy would take tightening/loosening the nuts a very long time without degrading badly.

If there is nothing, then you'll have to buy inserts of any sort.

As for the backspacing, if your centers are anything like mine, you'll need 4.5" wide inners for the "RSR" sizes.

Here mine:

[geof33]

George,

My wheels look just like yours. The inner width is 6". With a 25mm spacer they would just fit. I was thinking a 4" inner with a 7" outer. Would that be correct? or 4.5" inner with a 6.5 outer?

My wheels are not handy as they are in my shop. The pic above is of one of my rear wheels. It appears there are inserts in the wheels as the outer diameter fits the lugs closely...

I'll be in my shop tonight or tomorrow and I'll look closer and take a pic.

[beepbeep]

That looks like Compomotive CX500, not BBS.

I had a set of those...15 x 11.5 in back

[RaceProEngineer]

Hello again, Geof,

Sorry to have given you wrong information about those special tubular lug nuts. We were unaware that BBS has stopped providing them. Naturally we have a set, but (equally naturally) they are pressed into service regularly.

George has first hand knowledge of the new inserts, and if BBS says they work, you can depend upon it!

I would offer a word of caution when comparing measurements: Geof, your questions about total wheel offset and backspace are the only accurate way to go about this, BECAUSE (to make things even more confusing) BBS made and makes these centers themselves with various "offsets". So, for example, George may use 4.5" inners on his RSR, but 4.5" inners may not work for you if your centers have more "offset".

Another approach: If you are certain that a 25mm spacer will do the trick, and if your present inners are 6", then changing to a 5" inner will accomplish what you are after.

Ed

[Jim2]

Stud length for hub centric BBS motorsports E50 center as you have:

Wheel flange front = 0.600" (rear flange with rotor hat is about 0.500")
BBS E50 center and steel nut = 1.40"
Total 2.0" or 50mm
add thickness of your wheel spacer to total

Aluminum nuts work, steel ones last more cycles of on/off.








Maximum BBS inner/ outer half width is dependant on 911/930 trailing arms, or specific front hubs you are using, and which version of RSR fenders you have. E50 centers conflict with some brake calipers and may require spacers to clear. Put one of your wheels on your car and measure as shown in the following picture. Leave a little space for suspension bushing compression under cornering, oil lines, tire sidewall etc. Outer half can go to fender lip with appropriate clearance.

Regards
Jim

PS. Now I know who scooped this set of wheels on me. If you change the halves, I may buy your old ones.

[geof33]

Jim2,

Wow that is some great info... Sorry I won the wheels

So... to all... Here is where things sit with some new pics. I never thought mounting wheels could be so complicated!!

George, my wheels DO have the insert, so that saves some issues. It looks as though I'm going to need to use spacers anyway (brakes) so to keep things a bit cheaper and simpler in the long haul I'll do spacers (NOT adaptors) with the appropriate studs. I'd be looking at another 400.00 or so $$ not counting any return on my halves to redo the offset plus the rebuilding of the wheels etc. Sometime in the future I'll probably do it, but at that point I may have some 16 Fuch centers done for the RSR look. For now these with be perfect.

They are all BBS wheels. Some #'s on the centers 120-22 is a number. Is this a part number?

Here they are...

[beepbeep]

Interesting. They look very similar to Compomotive wheels I had. Sorry, I don't have better picture of them: