New Wheels... Wheels Arrived! Wheel Pron Page 6

[X53Jay4.8is]

Originally Posted by g300d

Those wheels look nice! Thin spokes, but in 20's they can pull it off.

CB is 72.6 and it would be best they make it that way. Wrong CB can cause wobble, even with adapters.

Do post pics when you get them in!

Reading through their site with the number of custom things that Forgestar does with their wheels I would imagine they will drill the Center Bore to be an exact fit to the X5 and avoid a lot of potential vibration hassle. I am looking forward to seeing these wheels on the X5 that X3 in the picture looks good with them. I think Crystalworks finish that he selected is going to be the finishing touch that sets the wheels off just right.

[crystalworks]

Originally Posted by X53Jay4.8is

Reading through their site with the number of custom things that Forgestar does with their wheels I would imagine they will drill the Center Bore to be an exact fit to the X5 and avoid a lot of potential vibration hassle. I am looking forward to seeing these wheels on the X5 that X3 in the picture looks good with them. I think Crystalworks finish that he selected is going to be the finishing touch that sets the wheels off just right.

Thanks again, and yes I am hoping as well that they are going to go with factory center bore. I can't see why they wouldn't.

Originally Posted by THE VEIN

why not just run the stock tire size?

Because wider is better. Well, for me anyway... visually speaking. If I could stuff 355's under there I would... I like that steam roller tire look. As I said, it's a personal preference thing.

Originally Posted by 4.8isX5

I believe offset on stock rear wheels (168s) is +35 if i recall...

To get them lined up with the rear factory flares like mine are youd need offset of only around +5 (if you are keeping factory width of wheel). If you are lowered say 1.5/2"s or more offset difference will need to be about another 20 extra.

I was hoping you would chime in after looking at that page Josh posted. Very nice X, love the wheels/stance. Here is what I found on the 168's... BMW wheel style 168 | BmwStyleWheels.com

It shows +30 in the rear. I saw you were running a +0 after spacer and agree with you that a +5ish (though I am switching to 20x11) would probably be necessary to get fender flush with the 325/35 tire. Looks like I will have to settle for +24 though as it is the lowest they offer in 20x11. Will ask them about it for sure.

Originally Posted by dabenthusiast

those will look nice!!



does $1500 seem steep for these 20" style 214?
BMW X5 wheels 20"

Thanks. I've always liked the 214's you are eyeing as well. Nice set of wheels. $1500 is pretty reasonable for the condition those appear to be in with run flats. Show up with cash and try to get a hundred bucks or so off. Can't hurt.

[THE VEIN]

why not just run the stock tire size?

[4.8isX5]

I believe offset on stock rear wheels (168s) is +35 if i recall...

To get them lined up with the rear factory flares like mine are youd need offset of only around +5 (if you are keeping factory width of wheel). If you are lowered say 1.5/2"s or more offset difference will need to be about another 20 extra.

[dabenthusiast]

those will look nice!!



does $1500 seem steep for these 20" style 214?
BMW X5 wheels 20"

[THE VEIN]

Originally Posted by dabenthusiast

those will look nice!!



does $1500 seem steep for these 20" style 214?
BMW X5 wheels 20"

that's about the general price you would see 20" BMW wheels with tires. I would try and talk the person down but i don't think anyone would think you're crazy for spending $1500

[4.8isX5]

Alright, i'll finally post my specs because been getting asked a bunch and if you dont want to run it this way you dont have to, anyhow...

My wheels are 10.5" all around (factory size of staggered rears either style 87s or 168s).

Tires are factory sized 275/315 combo with front having a slight strech.

I got a hell of a price on these wheels new which is why i did not go custom or anything else, they are +35mm offset all around.

Rear setup is one H&R DRA 30mm spacer, stacked ontop of that is another H&R DRA spacer but 25mm size. Total of 55mm a side in spacers. This makes the track of the tires 4.3 inches wider then factory.

Front setup is 10.5 wheel, and 25mm H&R DRA spacer. So front track is about 2" wider.

That is what you need to become basically flush with factory rear 4.8is flares and front lemans flares.

If you are running factory 4.8is ride height you will get away with 30mm spacers making you flush in rear or a lesser offset+ wheel. If your lowered like me the wheel naturally cambers in more at the top, as well as with wheel travel, even though its mostly flush in rear i am not smacking into the flares over bumps, it only catches on the inside plastic lip which already wore away what it needed.

[crystalworks]

^Thanks for posting that. Definitely more aggressive than I want to be @ et-20 in the rear. But as you said, you're lowered, running stock tire size, and can use the extra negative offset.

Maybe I should go slightly lower in the front than the +42 with a 285/40? You're sitting at et10 but again are lowered and running wider wheels. I'll be running factory width 9.5" up front. I've got anything available from +5 to +52 in the 9.5" wheel. Now I'm leaning towards +40 which sets the tire 10mm further out.

My rear tires are going to have more sidewall height, and more width... so I can't be that aggressive with the final offset. I'm hoping I can drop the rear offset to an et10 or something, but their website states 20x11 only goes down to et24. I don't like using spacers so that will be my final offset if they can't do any lower.

We'll see what they say/suggest. Thanks again for posting your specs.

[crystalworks]

So far no word from Modbargains or Forgestar. There is a long wait time for these wheels though... just hard to be patient. Did read some horror stories regarding ordering Forgestar's though, hope my transaction will be smooth. Hoping for wheels in less than 3 months, but did read of others having to wait longer.

[jdstrickland]

www.tirerack.com has a tire size calculator that is very good. It can be a bit tedious to compare multiple tire options, but you can build a chart with pen and paper.

I have a calculator that I made in Excel that calculates all of the pertinent dimensions and gives a spreadsheet of the results.

Basic Information
In a tire size of 235/65x17 -- factory base tire/wheel fitment -- the numbers, 235, 65, and 17 can be used to tell you the circumference of the tire. You can then change numbers and find the circumference of a different tire.

235 is the width of the tire, 65 is the aspect ratio or sidewall height as a percentage of the width, and 17 is the diameter. 235 and 65 result in numbers that are millimeters, and 17 is in inches.

Painful Details
For any practical purpose, if you have a tire width of 235 and want to keep it but also want a larger wheel (rim) then you have to reduce 65 by 5 for every inch of diameter change. For example, if you have a 235/65x17 and want to go to a 19, then you would need a 235/55x19 to have the same circumference tire.

This might not look very good, but it is a description that lays a foundation.

If you wanted to bump the 235 (width) to 315, then the aspect ratio would have to come down else the resulting tire would be to tall to fit the car. A 235/55x19 will have a sidewall height of 129.25mm. Dividing 129.25 by 315 gives us .41, or 40% (rounded). This tells us that you would want a 315/40x19. This should give a tire with a similar circumference as the factory base model tire.

You can use the tires on your car now as the basis of the calculations. Reduce the aspect ratio by 5 for every inch added in diameter of the new rim if your current aspect ratio is 55 and you are getting wheels that are 2 inches larger, then the new aspect ratio should be 45 to end up with the same circumference.

Multiply the current width by the new aspect ratio to find the sidewall height that is the target for the wheel.

Divide the target sidewall height by the desired new width to find the aspect ratio for the proposed width. You have to round the nearest 5%. (129.25 / 315 = 41, so the aspect ratio will be 40).

Because your X5 is all wheel drive, then you want the circumference of the front and rear tires to be as close as possible to identical. Identical is not likely to happen, but you need to be as close as you can get.

width x aspect ratio = sidewall height (in millimeters)
(sidewall height x 2) + diameter = outside diameter (in millimeters)
outside diameter / 25.4 = outside diameter in inches
outside diameter in inches x 3.14159 (pi) = circumference
5280 / circumference = revolutions per mile

You want the revolutions per mile of the front and rear tires to be as close as possible to the same. There is a variance that is allowed, my instinct is about 10 revolutions per mile difference, but I don't know for certain.

BMW offers a staggered fitment option in the tire packages of the X5M. If you looked up what the tires sizes are for the front and rear, you could determine the variance that the factory is okay with, then you would know if the tires you are looking at are within the variance.