Alfa 75 V6 - Wheels Spacers/Adapter

Started by Stirling75, November 08, 2017, 12:40:00 PM

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Stirling75

Hi Guys,

Just seeking a bit of advice, having difficulty trying to locate and source some period correct wheels for my 75 (5x98 PCD). On the aftermarket scene there isn't much available either. Ive been looking at perhaps purchasing some spacers/adapters from 5x98 to 5x100 (come as a 10mm - 15mm Spacer)

Wandering what the Pros & Cons are for doing this?

Cheers

julianB

#1
Pros- whatever wheels you want.
Cons- increased load on wheel bearings leading to premature failure,
Harder to get width sizing correct- you're pushing the rim's mounting face further away from the hub, so you may need to run narrower wheels. It will be a compromise no matter what you do.
Performatek or serpent autosport sell nice alloy ones, though.

Options:
-Wobble nuts or variation nuts.
Pros- easily get a 1mm variation on the nut, allowing 5x100 wheels.
Cons: centrebore needs to be exact, because these wheels are hub centric- the lip on the hub takes the load and the nuts just locate it.
Bolts holes on wheel may need enlarging.

Edit: can buy centering rings to step down from an incorrect centrebore diameter - you should definitely look at alloy ones and not plastic ones.

- Fit 156 etc wheels.
Pros- 5x98 PCD
Cons- some people just grind out the centrebore to allow the wheel to fit a Transaxle. It's a shit way to do it when you consider how the wheels are designed to be mounted (as above).
Narrower FWD offsets. These can be fixed with proper spacers from performatek.
I have some 156 super turismo 17x7s that I had to have re-sleeved with a proper Alfetta centrebore because someone got into them with a dremel. Not safe or cool.
They are for sale if you want to contact me.

- three piece wheels
Pros- perfect ferment, can dish the rim out for that 80s euro tuner look
Cons- cost
85 GTV6 "Juliet"
GTA conversion-
AHM ITB setup, Jim K manifolds & 10.3 cams, M84
17" Work Meister S1R
330mm Brembo front, vented rears
RS coilovers and bits
Recaro LX mesh headrest buckets

'68 step nose Junior "Romeo"
bare metal project

bteoh

The 75 has a centre bore of 58.6mm and most later FWD Alfas with 5 x 98 PCD has centre bores of 58.1mm. So if you are having spacers made up, make sure you specify a centre bore of 58.6mm
Good luck with your search  :)

VeeSix

I have wheels and spacers in stock

david.tracey75@bigpond.com
1985 Alfa Romeo GTV6 V6 2.5 12V 
1986 Alfa Romeo 90 V6 2.5 12V
1990 Alfa Romeo 75 V6 3.0 12V Potenziata
1990 Alfa Romeo 164 V6 3.0 12V Zender
1991 Alfa Romeo 164 V6 3.0 12V QV
1992 Alfa Romeo 164 V6 3.0 12V QV

jazig.k

Quote from: julianB on November 09, 2017, 04:57:42 PM
Pros- whatever wheels you want.
Cons- increased load on wheel bearings leading to premature failure,
Harder to get width sizing correct- you're pushing the rim's mounting face further away from the hub, so you may need to run narrower wheels. It will be a compromise no matter what you do.


Load on the bearing changes depending the the wheels weight, offset and width [probably many other factors too]. You could maintain the same factory specs running spacers if the wheel was the required specs.

The next comment about pushing the wheels out so require a narrower wheel. Actually, you need to get the correct offset wheel to suit the spacer and car [or get the correct spacer width to suit the car and offset you have available]. What do I mean? Well running a 19x10 et0 would be the same as running a 19x10 et50 with a 50mm spacer [the spacer brings the offset back to zero]. It's just maths.
et50 with a 25mm spacer would give you an effective offset of 25mm.
et38 with a 15mm spacer would effectively be 23mm.

Then, you need to remember that width and offset are relative. Change one, and the other changes. Because a 19x9 et0 fits, doesn't mean a 19x10 et0 will, it might scrub on the outer edge or the inner edge, who knows until you measure up.

105gta

Hi stirling75, I guess to answer your original question, there really is not much you can do and keep it looking period correct, except find old stock or used wheels. If it's choice you are after and ease of fitment than the wobble nut option is probably your best bet. It opens up the Subaru wheel choices and Toyota 86. But mostly in modern designs.  Yes hubcentric rings are required and I'd advise only hand tightening no rattle guns! ( from an engineering point of view) its what I use for 5x100 fitment. Basically in  the market most of these wheels are chrome and weird looking. But you can get some modern wheels that do suit. Sadly not a lot of options, generally extra large diameter and usually narrow by comparison. But if you look at BRZ/86 options you get the correct offsets 30-45 and more options for decent widths etc..
Keep in mind that with limited wheel arch space simple things like wheel alignment make a huge difference to clearance.
as an example my wheels are 17x9 all round on a gtv6, with 245 tires but require 20mm spacers on the rear with 2 deg of camber but without the camber I may not need any spacers.
1967 Giulia Sprint GT Veloce (WIP)
1985 GTV6 (WIP)

aggie57

Quote from: julianB on November 09, 2017, 04:57:42 PM

Cons: centrebore needs to be exact, because these wheels are hub centric- the lip on the hub takes the load and the nuts just locate it.


Even on hub-centric setups the load is never carried by the lip on the hub, least it shouldn't and you will eventually have a failure if it does.

The nuts provide clamping force between the wheel and the hub and the load is carried across the entire assembly.  Lots of reference material around about this.
Alister
14 Alfa's since 1977. 
Currently 1973 GTV 2000, 2020 911 C2S MT, 2021 Mercedes GLE350, 2023 Polestar 2 LRDM
Gone......far too many to list

Stirling75

Thanks guys for information and input. I think i will continue to source period wheels (requires more patience). I want the car to reminisce the old touring car period and have found a few suppliers ex-Europe that provide the correct dimensions for wheels. Will just require more saving.

Always keeping an eye on the forum for stuff for sale too helps. Thanks for assistance. 


julianB

Out of curiosity, what wheels are you looking at? Do you have a link?

http://www.ntmwheels.com

Will do nice 3 piece wheels with some great Alfa styles in there- the lancia 037 teledials are awesome
85 GTV6 "Juliet"
GTA conversion-
AHM ITB setup, Jim K manifolds & 10.3 cams, M84
17" Work Meister S1R
330mm Brembo front, vented rears
RS coilovers and bits
Recaro LX mesh headrest buckets

'68 step nose Junior "Romeo"
bare metal project