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[GregW / Oregon]

Originally Posted by TomTarzian

Dear Greg,

That's great. Are you sure about the respective diameters? If so, I'll order the right ring pronto. Thanks for finding this.

My dealer checked the available sizes--at least the ones available a few months ago--and I believe the 125/70-18 tire is the best size available for this use.

Godspeed,
Tom

Well, 125/70-80 is, as I calculate it, 2 x.70 = 1.4 x 125 = 175/25.4 = 6.9 = 18 = 24.9" OD. Stock 19" PS2s are 25.8"F & 26.3"R (18s are 25.7"F & 26.3"R). So, that's 1.4" smaller than rear, a little worrisome for the diff.

135/80-18 calcs at 2 x .80 = 1.6 x 135 = 216/25.4 = 8.5 + 18 = 26.5" OD. That's closer on both front and rear than the 125/70s (only 0.2" off in rear). I would go for the Caddy size, myself.

I am not 100% sure of the CB and ring. Ben at Tire Rack says, "I would guess that the X6 spare may not be machined in such a way as to accept a centering ring, but have not tried it myself to find out. My database has the X6 listed as a staggered centerbore (!), so BMW may have some kind of ring to use if the spare is going on the "small" hub. I do have part # 72.56RING which goes from 74mm to 72.56mm. I have no guarantee that this would work, but if I had to try something, that is what I would use."

With a steel wheel, as Ben says, a standard alloy wheel ring may not work. Worst case is you may get a slight vibration without the ring, but hey, it's an emergency, right? Rings are cheap, though, so you could try one.

So, jury is out. Care to be a test case?!!

Edit 3/3: My parts guy says the wheel is $165.

[TomTarzian]

Originally Posted by GregW / Oregon

Well, 125/70-80 is, as I calculate it, 2 x.70 = 1.4 x 125 = 175/25.4 = 6.9 = 18 = 24.9" OD. Stock 19" PS2s are 25.8"F & 26.3"R (18s are 25.7"F & 26.3"R). So, that's 1.4" smaller than rear, a little worrisome for the diff.

135/80-18 calcs at 2 x .80 = 1.6 x 135 = 216/25.4 = 8.5 + 18 = 26.5" OD. That's closer on both front and rear than the 125/70s (only 0.2" off in rear). I would go for the Caddy size, myself.

I am not 100% sure of the CB and ring. Ben at Tire Rack says, "I would guess that the X6 spare may not be machined in such a way as to accept a centering ring, but have not tried it myself to find out. My database has the X6 listed as a staggered centerbore (!), so BMW may have some kind of ring to use if the spare is going on the "small" hub. I do have part # 72.56RING which goes from 74mm to 72.56mm. I have no guarantee that this would work, but if I had to try something, that is what I would use."

With a steel wheel, as Ben says, a standard alloy wheel ring may not work. Worst case is you may get a slight vibration without the ring, but hey, it's an emergency, right? Rings are cheap, though, so you could try one.

So, jury is out. Care to be a test case?!!

Edit 3/3: My parts guy says the wheel is $165.

Dear Greg,

I think you may be right: the 135/80-18 size might be a better overall fit. On the other hand, I asked Mike Miller about the effect of the smaller size on the dif and he assured me it's not a problem. I'll try the plastic centering ring and let you know how it works.

Godspeed,
Tom

[likestogofast]

I agree with the plug kit... I have pluged a slice in the sidewall with several plugs at a time, used the goo in the BMW tire recue kit and was able to get the car to a suitable location.

[TomTarzian]

Originally Posted by GregW / Oregon

Thanks for that. Is that the same as use for the X3 (my post #11)? That calcs out to an inch or more smaller OD than stock. Wonder if there is a 125/80-18 available?

Edit: I just found that the Cadillac CTS uses a 135/80-18, which, at ~26.5", would be a little larger than the stock 26.3" rear.

I'm sure you could have an adapter machined pretty easily, but would be nice to find a pre-made one. Do you know the centerbore diameters? X5 is 74.1, so I assume X6 is the same? (M3 CB = 72.56).

Edit: I found the proper hubcentric plastic rings here (74.1/72.56): http://www.1010tires.com/hubrings.as...FU0wpAodcQqcmw $21/set of 4.

Dear Greg,

At the site you mention I find 74/72.56 but not 74.1/72.56.

Godspeed,
Tom

[GregW / Oregon]

Originally Posted by TomTarzian

Dear Greg,

At the site you mention I find 74/72.56 but not 74.1/72.56.

Godspeed,
Tom

Maybe is misquoted the CB spec, but 0.1 mm is 1/254", which is inconsequential.

[True Faith]

I ordered the X6 spare wheel from Tischer and a 125/70 18 tire from Tire Rack. However, the X6 wheel is 6" inches wide; I haven't tried it yet, but it looks like there is no way that a 125mm tire is going to fit on the 152mm rim.

The stock tire for the X6 is a 155/90 18, which is 2.5" bigger in diameter than the 265/40 18 rear tire.

I called Tire Rack to see if they have something closer (like maybe a 155/70 18), but they don't. The only thing they've got is the 155/90.

I am thinking that a 2.5" difference in diameter is too much, even for a temp. spare; I am also thinking that a 135 mm tire cannot be stretched to fit on a 6 inch rim. If I'm wrong about either of those, or if anyone has any other ideas, feel free to post.

[equ]

TomT,

Do you have a pic of your 125/70-18 on the x6 spare? If the x6 spare is indeed 6" wide, how does that look?

Thanks.

[GregW / Oregon]

Originally Posted by True Faith

I ordered the X6 spare wheel from Tischer and a 125/70 18 tire from Tire Rack. However, the X6 wheel is 6" inches wide; I haven't tried it yet, but it looks like there is no way that a 125mm tire is going to fit on the 152mm rim.

The stock tire for the X6 is a 155/90 18, which is 2.5" bigger in diameter than the 265/40 18 rear tire.

I called Tire Rack to see if they have something closer (like maybe a 155/70 18), but they don't. The only thing they've got is the 155/90.

I am thinking that a 2.5" difference in diameter is too much, even for a temp. spare; I am also thinking that a 135 mm tire cannot be stretched to fit on a 6 inch rim. If I'm wrong about either of those, or if anyone has any other ideas, feel free to post.

6" is too wide. It will also take up too much room in the trunk. Have you checked for X3 or X5 spares, or are those 17"? 4 1/2" wide would be ideal for the 135/80 CTS tre.

[True Faith]

Originally Posted by GregW / Oregon

6" is too wide. It will lso take up too much room in the trunk. Have you checked for X3 or X5 spares, or are those 17"? 4 1/2" wide would be ideal for the 135/80 CTS tre.

X3 looks like a 17" spare:

http://www.realoem.com/bmw/showparts...18&hg=36&fg=10

Here's a light alloy 18" wheel with a 40 mm offset from an X5--looks like 5" across.

http://www.realoem.com/bmw/showparts...44&hg=36&fg=95


Actually, it looks like my measuring skills are not what they could be, as the X6 wheel is listed as being 5" wide, not 6--at least, if I am reading the catalog right:

http://www.realoem.com/bmw/showparts...25&hg=36&fg=10


Of course, looking at the catalog more closely I see another potential issue--the lug bolts are different for the X5/X6 and the 3er.

All of this would be much easier if BMW would just make a frigging wheel for the E90 M3.

[GregW / Oregon]

Originally Posted by True Faith

X3 looks like a 17" spare:

http://www.realoem.com/bmw/showparts...18&hg=36&fg=10

Here's a light alloy 18" wheel with a 40 mm offset from an X5--looks like 5" across.

http://www.realoem.com/bmw/showparts...44&hg=36&fg=95


Actually, it looks like my measuring skills are not what they could be, as the X6 wheel is listed as being 5" wide, not 6--at least, if I am reading the catalog right:

http://www.realoem.com/bmw/showparts...25&hg=36&fg=10


Of course, looking at the catalog more closely I see another potential issue--the lug bolts are different for the X5/X6 and the 3er.

All of this would be much easier if BMW would just make a frigging wheel for the E90 M3.

Even 5" is going to be a stretch for the 135/80 tire. I have heard of having a custom wheel made up from 3-piece wheel parts.

Yes, wish BMW would address this issue. It would not take that much to do a wheel.

[TomTarzian]

Guys,

The X6 space saver spare wheel appears to be about 5" wide. This wheel, mounted with the 125/70-18 space saver spare tire and in a Tire Tote takes up about 5.5" of trunk space. There's still plenty of trunk space left. My car's been driven while having this wheel/tire combo mounted on the left front and it works just fine. As I wrote earlier, the only problem is the difference in the diameters of the center bore of the X6 wheel and the E9x M3's hubs, which requires very careful tightening of the lugs to properly center the wheel on the hub. Hopefully, the centering rings Greg found (and that I just ordered) will take care of that.

Godspeed,
Tom

[True Faith]

Originally Posted by TomTarzian

Guys,

The X6 space saver spare wheel appears to be about 5" wide. This wheel, mounted with the 125/70-18 space saver spare tire and in a Tire Tote takes up about 5.5" of trunk space. There's still plenty of trunk space left. My car's been driven while having this wheel/tire combo mounted on the left front and it works just fine. As I wrote earlier, the only problem is the difference in the diameters of the center bore of the X6 wheel and the E9x M3's hubs, which requires very careful tightening of the lugs to properly center the wheel on the hub. Hopefully, the centering rings Greg found (and that I just ordered) will take care of that.

Godspeed,
Tom

So you successfully mounted the 125 on the X6 wheel? Huh--good to hear. I guess I'll give it a shot.

Thanks! I'll post results once I have them.

[GregW / Oregon]

Originally Posted by True Faith

So you successfully mounted the 125 on the X6 wheel? Huh--good to hear. I guess I'll give it a shot.

Thanks! I'll post results once I have them.

I still think the 135 Caddy tire would be a better match in both width of the wheel and OD to stock.

[JC919]

I've got a spare wheel and tire from my e39 M5 that I carry in the trunk if I'm driving cross country or something. A caddy tires from a 135 is a damn good idea though

[True Faith]

It works. Had the tire mounted this morning; I agree with Greg that the 135/80 18 is probably a better choice, but rather than send back the 125/70 18 that I had ordered I decided to give that a go.

The tire guys laughed at me, but the tire popped right on to the rim. Looks kind of weird, but it works.

Thanks, Tom, for the guidance on this.

Also, I got the rings from 1010tires; despite being identified as 74-72.56 on the website, the actual rings are labeled 74.1-72.56, so they are exactly the right size. I haven't tried the wheel on the car yet, but based on Tom's findings I don't doubt it will work.

So: X6 wheel, about $130.

125 70 18 tire, about 130 shipped.

$15 to the guy for mounting.

$30 for the rings.


Here are some pictures.

[TomTarzian]

Originally Posted by True Faith

It works. Had the tire mounted this morning; I agree with Greg that the 135/80 18 is probably a better choice, but rather than send back the 125/70 18 that I had ordered I decided to give that a go.

The tire guys laughed at me, but the tire popped right on to the rim. Looks kind of weird, but it works.

Thanks, Tom, for the guidance on this.

Also, I got the rings from 1010tires; despite being identified as 74-72.56 on the website, the actual rings are labeled 74.1-72.56, so they are exactly the right size. I haven't tried the wheel on the car yet, but based on Tom's findings I don't doubt it will work.

So: X6 wheel, about $130.

125 70 18 tire, about 130 shipped.

$15 to the guy for mounting.

$30 for the rings.


Here are some pictures.

Great looking job--looks just like the one I have. Thanks for the info on the centering rings. Greg was right: the 74 OD on the 1010 website is a misprint.

Godspeed,
Tom

[arcsynesis]

True Faith,
If you don't mind me asking, where did you purchase your tire?
Arcsynesis

Originally Posted by True Faith

It works. Had the tire mounted this morning; I agree with Greg that the 135/80 18 is probably a better choice, but rather than send back the 125/70 18 that I had ordered I decided to give that a go.

The tire guys laughed at me, but the tire popped right on to the rim. Looks kind of weird, but it works.

Thanks, Tom, for the guidance on this.

Also, I got the rings from 1010tires; despite being identified as 74-72.56 on the website, the actual rings are labeled 74.1-72.56, so they are exactly the right size. I haven't tried the wheel on the car yet, but based on Tom's findings I don't doubt it will work.

So: X6 wheel, about $130.

125 70 18 tire, about 130 shipped.

$15 to the guy for mounting.

$30 for the rings.


Here are some pictures.

[GregW / Oregon]

Originally Posted by True Faith

It works. Had the tire mounted this morning; I agree with Greg that the 135/80 18 is probably a better choice, but rather than send back the 125/70 18 that I had ordered I decided to give that a go.

The tire guys laughed at me, but the tire popped right on to the rim. Looks kind of weird, but it works.

Thanks, Tom, for the guidance on this.

Also, I got the rings from 1010tires; despite being identified as 74-72.56 on the website, the actual rings are labeled 74.1-72.56, so they are exactly the right size. I haven't tried the wheel on the car yet, but based on Tom's findings I don't doubt it will work.

So: X6 wheel, about $130.

125 70 18 tire, about 130 shipped.

$15 to the guy for mounting.

$30 for the rings.

If you want to sell your extra rings, I'd buy one (after you''ve confirmed they work and that the wheel clears the brake). Thanks for being the guineau pig.

[TomTarzian]

Originally Posted by GregW / Oregon

If you want to sell your extra rings, I'd buy one (after you''ve confirmed they work and that the wheel clears the brake). Thanks for being the guineau pig.

Dear Greg,

The wheel definitely clears the brake. I've had it mounted on the left front and driven--no problem. It also fits fine on the rear.

Godspeed,
Tom

[True Faith]

Originally Posted by arcsynesis

True Faith,
If you don't mind me asking, where did you purchase your tire?
Arcsynesis

Tire Rack. About $115 plus shipping. I couldn't find it on the web site, but if you call and tell them you want a compact spare and give them the size, they can find it without a problem.

As for the rings, they definitely fit in the wheel. Haven't tried the wheel or rings on the car yet, because the weather has been crap and I'm sort of waiting until I have to take the snow tires off anyway--maybe a couple of weeks. I'll post as soon as I confirm the rings do the job, but I don't have any reason to think they won't.

[sayemthree]

$30 for the rings.


what are the rings? you mean spacer?

[sayemthree]

I have the old 330i spare from my e46. It looks like it may fit with a 25 or 30 mm spacer. anyone try this?