eNate
Posts: 438
Joined: Mon Sep 09, 2019 5:33 pm

Junkyard Wheel, Wrong Size! :(

Mon Feb 24, 2020 10:37 am

Wanting to have a spare wheel on hand, I ordered up a 10-spoke 428 "cyclone" wheel off a wrecked i3 from my friendly online auto dismantler.

It was delivered over the weekend and I just unwrapped it.

Good news is it looks nearly perfect, and unexpectedly came with a tire mounted, in great shape with plenty of tread left.

Bad news is it's BMW p/n 6856895 which is the 5.5" rear wheel, with a 175 Ecopia mounted. I want to be able to use this as a spare in all four positions.

I understand that when the rear wheel is mounted to the front, something sometimes rubs something.

But in reality is it the tire, not the wheel, that rubs? Can I swap on one of my 155 tires and be OK?

I've found reference that the front 5Jx19 wheel has an ET43 offset, but I can't find an offset listing for the 5.5Jx19. Is it also ET43?

I see that the i3s 5.5Jx20 is ET33, but I suspect that's unique to the Sport.

My suspicion is as long as the lip of the rim clears the strut, a 155 tire on the 5.5 wheel ought to work with no clearance problems.

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electronchaser
Posts: 79
Joined: Fri Nov 08, 2019 3:14 pm

Re: Junkyard Wheel, Wrong Size! :(

Mon Feb 24, 2020 3:02 pm

not really a bummer if you can find one more 175 and then use one of the old 155 fronts as an all around spare. But yes a 10mm spacer will keep from contact on full lock of steering wheel. The spacers are highly recommended. After fitting 15mm spacers at each corner I found every aspect of the suspension improved. From less roll in turns, to more stability when I pass a 18wheeler/cross winds, to less bounce when going over poorly paved roads.

Personally I'd go 175s all around. with a 155 spare. (take up a few lbs and inches less space as well)
Am I trashing it?, absolutely, but with love, like every other BMW I've owned.
Rondel stands for something, and I fully utilize all the non neutered abilities its got.
Takeaway. This is an amazing piece of engineering. And I'm not impressed with 'stuff'

joni3s
Posts: 56
Joined: Wed Oct 02, 2019 11:16 am
Location: VA

Re: Junkyard Wheel, Wrong Size! :(

Tue Feb 25, 2020 5:41 am

The inside of the rim should have the number, where it says 5.5Jx19, there should be soon a trailing IS number. that is the ET IIRC
2018 I3s rex

eNate
Posts: 438
Joined: Mon Sep 09, 2019 5:33 pm

Re: Junkyard Wheel, Wrong Size! :(

Thu Feb 27, 2020 8:07 pm

joni3s wrote:
Tue Feb 25, 2020 5:41 am

The inside of the rim should have the number, where it says 5.5Jx19, there should be soon a trailing IS number. that is the ET IIRC

Thank you Jon! I didn't know about the 'IS' notation for offset.

So it turns out the rear is designated 53mm offset, so 10mm deeper than a front wheel (43mm offset).

Combined with the additional ½" rim width, this pencils out to the inner rim lip being 16.4mm closer to... whatever (usually the strut). The face of the wheel slides in about 3.6mm.

Equally importantly, if I mount a 155 tire to the 5.5 wheel, and mount it up front, the tread ought to shift inward about 10mm, and the sidewall will have to make up the 6.4mm difference to where the bead seats against the lip of the rim.

So now all I have to do is measure my current clearances, and if that looks reasonable, find a 155 to mount up and check it out.

Although, frankly, I'd rather this guy sends me the wheel he advertised!

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eNate
Posts: 438
Joined: Mon Sep 09, 2019 5:33 pm

Re: Junkyard Wheel, Wrong Size! :(

Sat Feb 29, 2020 4:47 pm

I took a gander at the layout behind my i3 front wheel. I didn't have my calipers to get a truly accurate measurement of the available clearances, so I improvised. My measurements are approximate, not precise.

Doesn't look good!

It appears the stock setup (5.0" wheel with 43mm offset) provides 12mm of clearance between the lip of the rim and the strut, as depicted in the photo below.

This means I'd definitely need at minimum a 5mm spacer to take away from the 16.4mm inset of the rear rim mounted in this position, and although my measurements aren't exact, this would be perhaps be too close for comfort.

The other concern is that the coils reduce that clearance even further. The coils are clear of the rim, but could contact the tire, depending on how the front 155 tire fits to the wider rear 5.5" wheel.

This guy at the wrecking yard where I ordered from is ghosting me, so I'm not too hopeful I'll get the correct wheel (I may dispute the credit card charge, which is entirely another matter). So I may be stuck making do with this wheel. I want to get this resolved before I start dismounting tires and scavenging 155 tires to mount up. I can't test fit the wheel up front until the 175 rubber is removed.

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jadnashuanh
Posts: 4986
Joined: Thu May 22, 2014 2:07 pm
Location: Nashua, NH USA

Re: Junkyard Wheel, Wrong Size! :(

Sat Feb 29, 2020 6:27 pm

Keep in mind that as your air pressure may change or you hit a bump, the sidewalls will bulge out a bit. So, depends on how far you let it get, or how big of a bump you hit.

Somewhere on the forum, there's someone who had some service work done, and they installed a rear tire on the front...trashed the tire within a couple of blocks. Got new tires out of it, though!
Jim DeBruycker
2011 535i x-drive GT, 2014 i3 BEV
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KarlC
Posts: 44
Joined: Wed Nov 27, 2019 1:15 pm
Location: San Diego Ca

Re: Junkyard Wheel, Wrong Size! :(

Tue Mar 03, 2020 12:05 pm

eNate wrote:
Mon Feb 24, 2020 10:37 am
Wanting to have a spare wheel on hand, I ordered up a 10-spoke 428 "cyclone" wheel off a wrecked i3 from my friendly online auto dismantler.

It was delivered over the weekend and I just unwrapped it.

Good news is it looks nearly perfect, and unexpectedly came with a tire mounted, in great shape with plenty of tread left.

Bad news is it's BMW p/n 6856895 which is the 5.5" rear wheel, with a 175 Ecopia mounted. I want to be able to use this as a spare in all four positions.

I understand that when the rear wheel is mounted to the front, something sometimes rubs something.

But in reality is it the tire, not the wheel, that rubs? Can I swap on one of my 155 tires and be OK?

I've found reference that the front 5Jx19 wheel has an ET43 offset, but I can't find an offset listing for the 5.5Jx19. Is it also ET43?

I see that the i3s 5.5Jx20 is ET33, but I suspect that's unique to the Sport.

My suspicion is as long as the lip of the rim clears the strut, a 155 tire on the 5.5 wheel ought to work with no clearance problems.
I may have an extra 5" wheel that I would trade for your 5 1/2" wheel if you wanted.

Thx Karl

.
2015 i3 Rex, Arravani Grey, Tera World, Technology, Driving & Parking Assistant, Harman Kardon Audio System, 19" wheels

eNate
Posts: 438
Joined: Mon Sep 09, 2019 5:33 pm

Re: Junkyard Wheel, Wrong Size! :(

Tue Mar 03, 2020 12:32 pm

Is this the 428 "cyclone" style? You say in your sig you're running 20? I'm 19.

I got the seller on the phone yesterday. He was going to call me back, but of course he didn't. Must have missed my emails, too.
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KarlC
Posts: 44
Joined: Wed Nov 27, 2019 1:15 pm
Location: San Diego Ca

Re: Junkyard Wheel, Wrong Size! :(

Tue Mar 03, 2020 6:16 pm

eNate wrote:
Tue Mar 03, 2020 12:32 pm
Is this the 428 "cyclone" style? You say in your sig you're running 20? I'm 19.

I got the seller on the phone yesterday. He was going to call me back, but of course he didn't. Must have missed my emails, too.
I have some 428 19" wheels now and 4 - 20" wheels I will be welling soon.

So yes I will have an extra 5x19 428 wheel if you want to trade

.
2015 i3 Rex, Arravani Grey, Tera World, Technology, Driving & Parking Assistant, Harman Kardon Audio System, 19" wheels

eNate
Posts: 438
Joined: Mon Sep 09, 2019 5:33 pm

Re: Junkyard Wheel, Wrong Size! :(

Tue Mar 10, 2020 1:07 pm

Good news! I been in contact with the salvage yard and they're shipping me the correct wheel.

Rear wheel is gone!
Last edited by eNate on Mon Mar 16, 2020 6:00 pm, edited 1 time in total.
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