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[pennychow]

Please refer to the diagram below.

The main issue is "is it safe to add 5mm spacer in the rear wheel?"

there are some facts to be noticed (pls correct me if I am wrong):
1) the lip length of rear stud is 12mm;
2) there is an "edge" of the rim;

after adding 5mm spacer (diagram C & D), there should be 7mm lip left for contact with the rim.
however, as there is an "edge" of the rim, the actual contact length (should be area in 3-dimmension) is only about 5mm or less (refer to the red rectangle in diagram D)

the question is, is it enough for only 5mm (or less) hub-central length for the wheel?

Pls give advice. thanks a lot !!

[Daniel08E93]

If you're throwing spacers regardless if it's just 5mm and you're worried about safety you should buy extending lug bolts or a stud conversion kit if they did not already come with the spacers you purchased. Some people will run 5mm spacers on stock lug bolts but IMHO it is not worth taking a chance especially when the hardware you need is fairly inexpensive.

[pennychow]

Originally Posted by Daniel08E93

If you're throwing spacers regardless if it's just 5mm and you're worried about safety you should buy extending lug bolts or a stud conversion kit if they did not already come with the spacers you purchased. Some people will run 5mm spacers on stock lug bolts but IMHO it is not worth taking a chance especially when the hardware you need is fairly inexpensive.

Thanks!

but you are not answering my que. I am not asking anything about extended bolt.

I will surely buy extended bolt for 5mm spacer.
the main issue is whether "there are enough space for the rim to sit on the hub lip."

[Daniel08E93]

Originally Posted by pennychow

Thanks!

but you are not answering my que. I am not asking anything about extended bolt.

I will surely buy extended bolt for 5mm spacer.
the main issue is whether "there are enough space for the rim to sit on the hub lip."

Lmao! I totally misread that but yes it will be safe and you will have enough room for the wheel to sit on the hub if the 5mm spacer you are using does not have a hubcentric ring but that's as much as you can "safely" do if you go any bigger you'll need the ring on the spacer as well. Sorry about that

[tomasis]

have you seen wheel spacers? They are not entirely flat but have lip extension inside wheel spacers

[pennychow]

Originally Posted by tomasis

have you seen wheel spacers? They are not entirely flat but have lip extension inside wheel spacers

Of course I know much about spacer. I am using 10mm for front wheel.

But There is no lip extension for spacer thinner than 10mm.

5mm is only a flat plate.

[freakystyly]

Hub extenders exist, they are placed inside the hub (very tightly) and extend your hub. Just like it sounds... I made my own out of aluminum on a lathe, and later bought a real set.

[tomasis]

Originally Posted by pennychow

Of course I know much about spacer. I am using 10mm for front wheel.

But There is no lip extension for spacer thinner than 10mm.

5mm is only a flat plate.

you shouldn't worry. Eibach and H&R produce quality stuffs. They would create lips for 5mm if they saw reason. I'm not engineer but I would trust them.

Originally Posted by freakystyly

Hub extenders exist, they are placed inside the hub (very tightly) and extend your hub. Just like it sounds... I made my own out of aluminum on a lathe, and later bought a real set.

AFAIK, those only work on the front...and only for non-AWD cars.

OP what's the point of running such a small spacer to begin with? Like, what exactly are you trying to solve for?

If you already have 10mm at your disposal, run those in the rear. If you don't rub, etc. just run those....problem solved.

[pennychow]

Originally Posted by freakystyly

Hub extenders exist, they are placed inside the hub (very tightly) and extend your hub. Just like it sounds... I made my own out of aluminum on a lathe, and later bought a real set.

hub extender to extend the hub..... I have heard of that. OF course to add this extender is more safe.

But still wonder if 5mm spacer only is safe or not.

my point is if for rear wheel, hub lip is 12mm, minus 5mm, 7mm left for the rim should be safe.

but considering the "edge" of the mounting pad of the rim (refer to diagram A and D), the actual contact length of the lip and rim is less than 7mm, may be 3 to 4 mm only.

is it enough??

[pennychow]

Originally Posted by FCobra94

AFAIK, those only work on the front...and only for non-AWD cars.

OP what's the point of running such a small spacer to begin with? Like, what exactly are you trying to solve for?

If you already have 10mm at your disposal, run those in the rear. If you don't rub, etc. just run those....problem solved.

My present situation is:

Front: add a 10 mm spacer already (hub lip is 10mm). Everything fine.

Rear: no spacer now. after measurement, I find 5mm spacer can be added while 10mm is too thick which may cause rubbing.

that's why i make this post.

[pennychow]

Originally Posted by tomasis

you shouldn't worry. Eibach and H&R produce quality stuffs. They would create lips for 5mm if they saw reason. I'm not engineer but I would trust them.

Eibach and H&R do not produce 5mm spacer with lips.....

don't kidding

[pennychow]

to make it more clear, the enlarged diagram is attached for easy reference

is the length highlighted in red is enough for the rim to rely on?

[tomasis]

Originally Posted by pennychow

Eibach and H&R do not produce 5mm spacer with lips.....

don't kidding

don't be a fool!

if they don't so you don't need lips.

[Tambohamilton]

The reason why they don't make 5mm with a spigot ring is because they can't! Since the rim sits snugly over the hub, there isn't room for a spigot ring attached to the spacer. They can only do this when the spacer extends past (or at least flush with) the hub ring. Personally, I wouldn't run it. Or I would at least run a hub extender with it. However, since they are offered for sale, I'm sure they have been tested as safe, so long as the bolts/studs are long enough! The worst that can happen, so long as the correct bolts/studs are used, is that you get vibration etc. If that happens, you know you need to do something better to centralise the rim on the hub.

[pennychow]

Originally Posted by tomasis

don't be a fool!

if they don't so you don't need lips.

if you can find a 5mm spacer with lip, you are not fool.

if you cannot, you are fool !!!

[pennychow]

Originally Posted by Tambohamilton

The reason why they don't make 5mm with a spigot ring is because they can't! Since the rim sits snugly over the hub, there isn't room for a spigot ring attached to the spacer. They can only do this when the spacer extends past (or at least flush with) the hub ring.

Yes, you are correct!

Originally Posted by Tambohamilton

Personally, I wouldn't run it. Or I would at least run a hub extender with it. However, since they are offered for sale, I'm sure they have been tested as safe, so long as the bolts/studs are long enough! The worst that can happen, so long as the correct bolts/studs are used, is that you get vibration etc. If that happens, you know you need to do something better to centralise the rim on the hub.

Thanks !!

I think 5mm spacer should be safe if the famous manufacturers (H&R, Eibach) have designed it for BMW car (*provided that to use extended bolt).
Just want to hear any users with experience and research on this.

[tomasis]

Originally Posted by pennychow

I think 5mm spacer should be safe if the famous manufacturers (H&R, Eibach) have designed it for BMW car (*provided that to use extended bolt).

its what I said.. fool!

[Tambohamilton]

Originally Posted by tomasis

its what I said.. fool!

No; you said they'd make them with a spigot if they saw the need. But the OP's point is that it's not possible (unless you bore out the rim); they may see the need for a spigot, but they don't make them with one because they can't.

However, we're all in agreement that the product they offer must have been certified as safe, so it's probably OK to run them.

Originally Posted by pennychow

My present situation is:

Front: add a 10 mm spacer already (hub lip is 10mm). Everything fine.

Rear: no spacer now. after measurement, I find 5mm spacer can be added while 10mm is too thick which may cause rubbing.

that's why i make this post.

"May cause rubbing."

Won't know until u try and it will literaly cost you $0 to find out.

[pennychow]

Originally Posted by FCobra94

"May cause rubbing."

Won't know until u try and it will literaly cost you $0 to find out.

I need to buy spacer to try and test. I wonder why say it cost me $0....

[pennychow]

Originally Posted by Tambohamilton

No; you said they'd make them with a spigot if they saw the need. But the OP's point is that it's not possible (unless you bore out the rim); they may see the need for a spigot, but they don't make them with one because they can't.

However, we're all in agreement that the product they offer must have been certified as safe, so it's probably OK to run them.

Correct!!!