Aftermarket Rims and Center Bore Compatibility Question

limited60 · 03-17-2021, 12:16 PM

It seems the center bore of most aftermarket rims vary quite a bit, for some obvious reasons. The first being that each manufacturer will have different OEM specs, and aftermarket companies have to produce rims to fit.

I get that.

When I key in my vehicle data for compatible rims, I see 72.6 AND 74.1 come up (I believe my 2018 F30 330i x-drive is 72.6).

Can anyone tell me the story behind why 74.1 comes up so often?

Also, if both are correct (due to reducers or something), are there other center bore's that are also compatible, and do those affect offset?

Thanks!

alohasurftoad · 03-17-2021, 12:41 PM

F3/4 series centerbore is 72.56. the number is often rounded up to 72.6 and sometimes rounded down to 72.5 on some japanese wheel specs.

if the new wheel hub bore is smaller than 72.56 it won't fit. anything bigger will fit however a hub centering ring would be needed to fill the gap. so if you buy a rim with 74.1, you need a 72.56-74.1 hubcentric ring.

fyi, i've used wheels with larger bore than my hubs, without rings, on numerous occasions without issue. wheel is centered using a typical star method to torque lug nuts on a stud kit, though. with BMW lug bolts, hubcentric rings would be prudent if necessary.

hubcentric rings do not affect offset.

limited60 · 03-17-2021, 03:16 PM

Quote:

Originally Posted by alohasurftoad

F3/4 series centerbore is 72.56. the number is often rounded up to 72.6 and sometimes rounded down to 72.5 on some japanese wheel specs.

if the new wheel hub bore is smaller than 72.56 it won't fit. anything bigger will fit however a hub centering ring would be needed to fill the gap. so if you buy a rim with 74.1, you need a 72.56-74.1 hubcentric ring.

fyi, i've used wheels with larger bore than my hubs, without rings, on numerous occasions without issue. wheel is centered using a typical star method to torque lug nuts on a stud kit, though. with BMW lug bolts, hubcentric rings would be prudent if necessary.

hubcentric rings do not affect offset.

Thanks!

One more thing, how much tolerance is there in changing from the stock offset of 34. I'm bone stock, so what's the upper limit for offset? I am looking at an 18x8 set but is has a 35mm offset, what's that going to do? Probably not much? I really don't want my wheels moving IN much, and would prefer out just a tad, but will this even be an issue?

Knowing a range would help.

Thanks!

frchdragon · 03-17-2021, 03:32 PM

Here is a great website to see all the center-bore at a glance: https://hubbore.com/bmw/
You now need to get a rim with similar offset. I am going to try my 5 series rims with R comp to see if they fit, 5 series offset is usually much smaller.

Here is a wheel guide from Turner: https://www.turnermotorsport.com/t-wheel_guide

limited60 · 03-17-2021, 03:40 PM

Quote:

Originally Posted by frchdragon

Here is a great website to see all the center-bore at a glance: https://hubbore.com/bmw/
You now need to get a rim with similar offset. I am going to try my 5 series rims with R comp to see if they fit, 5 series offset is usually much smaller.

Here is a wheel guide from Turner: https://www.turnermotorsport.com/t-wheel_guide

Can't believe I never found those sites - very helpful. Thanks!

alohasurftoad · 03-17-2021, 04:52 PM

Quote:

Originally Posted by limited60

One more thing, how much tolerance is there in changing from the stock offset of 34. so what's the upper limit for offset? I am looking at an 18x8 set but is has a 35mm offset, what's that going to do? I really don't want my wheels moving IN much, and would prefer out just a tad, but will this even be an issue? Knowing a range would help. Thanks!

the offset range will depend on the width of the wheel and the tire size you are planning on using.

18" OEM square 400M, 398, or 397 are 18x8 +34 with 225/45/18. 18x8 +35 is tucked in 1mm more. it is a non issue. personally i would use a 235/45/18 if that tire size exists in the said size. here's what it looks like on an x-drive. being slightly taller, it improves the fenderwell gap a lot. https://f30.bimmerpost.com/forums/sh...+235%2F45%2F18

aardate · 03-17-2021, 06:40 PM

I just put after market wheels on my car. The front offset on the new wheel was 35 but the wheel would not clear the brake caliper due to its shape so I added a 10mm spacer to effectively push the wheel out away from the brake caliper.

I gotta tell you, the wheels looks so much better with the new look. My advice is get wheels with 10-12mm lesser offsets than OEM. I would go for 25 front offset and 35 rear. The OEM offsets have the wheels tucked in too much into the fenders.

03-17-2021, 12:16 PM	#1
limited60 Enlisted Member 6 Rep 37 Posts Drives: 2018 330i xDrive Sedan Join Date: Apr 2019 Location: Calgary, AB, Canada iTrader: (0)	Aftermarket Rims and Center Bore Compatibility Question It seems the center bore of most aftermarket rims vary quite a bit, for some obvious reasons. The first being that each manufacturer will have different OEM specs, and aftermarket companies have to produce rims to fit. I get that. When I key in my vehicle data for compatible rims, I see 72.6 AND 74.1 come up (I believe my 2018 F30 330i x-drive is 72.6). Can anyone tell me the story behind why 74.1 comes up so often? Also, if both are correct (due to reducers or something), are there other center bore's that are also compatible, and do those affect offset? Thanks!
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03-17-2021, 12:41 PM	#2
alohasurftoad Brigadier General 3075 Rep 4,318 Posts Drives: 440i gran coupe w/mppsk Join Date: Apr 2015 Location: hawaii iTrader: (0)	F3/4 series centerbore is 72.56. the number is often rounded up to 72.6 and sometimes rounded down to 72.5 on some japanese wheel specs. if the new wheel hub bore is smaller than 72.56 it won't fit. anything bigger will fit however a hub centering ring would be needed to fill the gap. so if you buy a rim with 74.1, you need a 72.56-74.1 hubcentric ring. fyi, i've used wheels with larger bore than my hubs, without rings, on numerous occasions without issue. wheel is centered using a typical star method to torque lug nuts on a stud kit, though. with BMW lug bolts, hubcentric rings would be prudent if necessary. hubcentric rings do not affect offset.
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03-17-2021, 03:32 PM	#4
frchdragon Lieutenant 338 Rep 417 Posts Drives: 2016 BMW M4 Join Date: Feb 2021 Location: ON, Canada iTrader: (0)	Here is a great website to see all the center-bore at a glance: https://hubbore.com/bmw/ You now need to get a rim with similar offset. I am going to try my 5 series rims with R comp to see if they fit, 5 series offset is usually much smaller. Here is a wheel guide from Turner: https://www.turnermotorsport.com/t-wheel_guide __________________ '16 M4 bone stock '13 335ix Msport BM3 stage1 - MAD FMI - FTP CP - Bilstein B4 (SOLD) '85 635csi M30 turbo race car (SOLD)
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03-17-2021, 06:40 PM	#7
aardate First Lieutenant 194 Rep 343 Posts Drives: X4MC Join Date: Aug 2020 Location: Houston, TX iTrader: (0)	I just put after market wheels on my car. The front offset on the new wheel was 35 but the wheel would not clear the brake caliper due to its shape so I added a 10mm spacer to effectively push the wheel out away from the brake caliper. I gotta tell you, the wheels looks so much better with the new look. My advice is get wheels with 10-12mm lesser offsets than OEM. I would go for 25 front offset and 35 rear. The OEM offsets have the wheels tucked in too much into the fenders.
	Appreciate 0 Quote