04-15-2009, 01:45 PM
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Registered User
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Wheels 10mm spacer = too much offset?
Hi all,
I have some vented disc and 4 pots that I want to fit to my 1750 Spider. My current wheels are Cromodora Mag daytonas with 23mm offset.
However, to get the clearance needed for the calipers, I have to insert a 10mm spacer between wheel and disc.
My question is, by inserting a 10mm spacer into this setup will this result in too little negative offset? since I am pushing the wheel outwards by another 10mm from an already shallow 23mm offset provided by my cromodoras Heavy steering? suspension geometry problem? hub wheel bearings issues?
I can't find 33mm or similar offset for a reasonable price at the moment.
Any views on this is greatly appreciated.
fgc
1750 spider
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04-15-2009, 02:26 PM
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Darth Slacker
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Join Date: Mar 2006
Location: Northern NY, USA
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I occasionally use a 10mm set on the rears only of my S3 with no problems with clearance or any of the other items you asked about. However, they do cause the car to run 'looser' by a quite noticable amount.
Pushing the wheels out up front might add a bit of understeer but prolly nothing else that you'd notice AFA heaviness or geometry.
As to there being issues in general, 10mm shims on 23mm wheels is no different than shimless 13mm wheels.
Last edited by Tifosi; 04-16-2009 at 11:27 AM.
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04-16-2009, 03:15 AM
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These spacers you are considering are they hubcentric?
From another marque but good info. Gleaned from the web.
Hubcentric Adapter
Whenever possible avoid the use of spacers or adaptors of any kind.
Properly fitted wheels are a better solution but I know expensive. Spacers were outlawed in many forms of racing a long time ago. Many people elect to use them on roadcars but for many mechanical/safety reasons they are not recommended.
I won't put any thing but a properly mounted hubcentric wheel on an Alfa or many other vehicles.
There is a lot of info on the web about this issue.
Offset is an issue however correct mounting of the wheel is critical to many things.
http://en.wikipedia.org/wiki/Offset_(wheel)
10mm Hubcentric spacers - The FIAT Forum
BMP design : Why use wheel spacers?
Suspension geometry vs wheel spacers/safety would be an interesting topic .
I'm sure someone has covered these issues before. Think about wheel stud length and diameter as the wheel moves outboard as just one of the considerations. As you can see fiat does sell these type of products. But there are many things to consider here.
Most people choose wheel spacers as a simple/cheap solution.
Wheels that are fitted via a hubcentric ring are also a good solution.
Reformed machinist/............
Please no offence meant to Tifosi !!!
Last edited by CanukSpider; 04-16-2009 at 07:25 AM.
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04-16-2009, 09:13 AM
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 Quote:
Originally Posted by CanukSpider
These spacers you are considering are they hubcentric?
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The OEM wheels were not hubcentric, as the front and rear hubs on a Spider are different sizes!!!
[The GTV/6, Milano, and 164 are hubcentric designs, but not the 105/115 series cars]
Last edited by JoeCab; 04-16-2009 at 09:16 AM.
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04-16-2009, 10:22 AM
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Darth Slacker
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Quote:
Originally Posted by CanukSpider
no offence meant
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If one is going for hubcentric spacers though, avoid the type that doesn't also have a flange big enough to completely engage/encircle the lug studs also.
Those that don't have a nasty habit of turning the hub into a fulcrum which can create way much more stress on the studs when sideways forces are applied to the wheels resulting in broken studs mid turn or bounce. (been there, done that...)
Flat spacers that are as big as the face of the wheel and/or hub face are actully safer in those cases, provided one checks lug nut tension regularly with a torque wrench. (which we all do weekly anyway as a matter of course, right?)
Last edited by Tifosi; 04-16-2009 at 10:27 AM.
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04-16-2009, 11:12 AM
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Quote:
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I can't find 33mm or similar offset for a reasonable price at the moment.
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I'm running an 11mm offset wheel on my Alfetta. It rides OK, but I may have lost some of the crispness it used to have. I may try to mill off a bit on my next tire change. I'll have to check with some wheel experts to see how much is safe.
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iachella [at] gmail [dot] com
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04-16-2009, 11:25 AM
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Darth Slacker
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Quote:
Originally Posted by iachella
By the way, a 23mm offset wheel with a 10mm spacer makes it a 13mm offset wheel, not a 33mm.
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Corrected my post above.
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04-16-2009, 11:36 AM
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Or maybe fgc wants to find a 33mm wheel so that with his 10mm spacer, it will get back down to 23mm. If that's the case and he'll look for another wheel, better look for a 15" wheel and that will probably clear the brakes easily.
On my GTV I have put 15" wheels with 30mm offset. I put 5mm spacers and am now at 25mm offset. Much happier. Steering is crisp again.
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Stefano
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04-16-2009, 01:06 PM
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Back to the original poster's dilemma about big brake clearance: the other thing to consider besides offset is the shape of the spokes on the wheel. Some wheels have spokes that curve outward and give more clearance. It may be possible to find a wheel that is in the normal range of offsets and still clears the brakes he intends to fit.
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04-16-2009, 01:22 PM
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Darth Slacker
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Mabe something FWD?
They tend to have that kind of shape and lean toward giving more space behind the wheel in general.
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04-16-2009, 06:31 PM
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Should not wheels used with spacers have at the very least an extended lug nut? Wheel spacers: A safety concern? - E46Fanatics
All kinds of people will chime in with opinions but please always consider safety first.
Perhaps an Alfa safety forum would be a good idea.
Any person giving advice that might in any way compromise someones safety can be a concern.(perhaps a liability)
I.E. fuel shut off switches or wheel mounting or any thing that could affect someones safety.
I have been building and modifying cars for many years and wheel spacers are not the best solution to wheel fitment issues........
A proper fitted wheel is best for many reasons.
I do not want to have to get into detailed explanations why, there are automotive engineering forums about this.
Just Buy the right correct fitting wheels if you need those brakes. The total solution will work out better.
Last edited by CanukSpider; 04-16-2009 at 06:52 PM.
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04-16-2009, 06:40 PM
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on my spider (84) i run front drive offsets.. i think ford focus offset..and have 25mm 'H&R' spacers on the front.. it works well..yes, i also have vented front rotors and 4 pot alum. cailpers on the front as you do.. good clearence..i think my front track is 3" wider than the rear.. will check alinmnet printout toninght.5mm spacers in the rear.also i run 16" wheels
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Last edited by bianchi1; 04-16-2009 at 06:46 PM.
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04-16-2009, 06:54 PM
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Darth Slacker
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Quote:
Originally Posted by CanukSpider
Should not wheels used with spacers have at the very least an extended lug nut
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Making the studs or nuts longer doesn't really increase that strength, (it can actually reduce it as it gives more threads for the nut to pull as linear stress against the one thread thats at the end of the nut where studs commonly break), though standards for minimum length for generic/not dressy lug nuts seems to hover roughly around (I've never measure to confirm, purely observational) the 'diameter + 1/3 to 1/2' length as it allows for the tapered portion followed by the thicker hex portion with the tapered portion being discounted as not much more than a wheel alignment guide and the hex portion being the true anchoring section (the thickness of which when each side is added together usually equals right around the diameter of the stud. EG: 3/8" OD stud, each 'wall' of the nut would be around 3/16")
In a same OD and thread pitch comparison, a 2" long bolt with a fully engaged 1 1/2" nut on it isn't going to hold any more or be any stronger than a 1" long bolt with a fully engaged 1/2" long nut. There will just be less sticking out overall when assembled.
Granted on a wheel using shims, you most certainly want to have enough stud stucking out to actually get a proper amount of thread engagement and just slapping a set on without checking to be sure is folly. (comparatively speaking, Alfas seem to have long studs in general. Pehaps becuase of the variety of steel and alloy wheels that were offered)
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04-16-2009, 07:04 PM
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I GIVE UP there is no winning in this it's about safety. I am done.
This one issue may well have finished me with Alfa BB.
Do whatever.
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04-16-2009, 07:18 PM
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Darth Slacker
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I agree its about safety and I agree about proper wheels being better than shimmed ones in the greater scheme of things.
All I'm saying is that if there's proper stud protrusion then that's all that's needed. Adding length to the lug nuts isn't going to improve the already adiquate length of thread engagement given by the standard lugs provided all the threads on the nut are engaged. Nor is a longer nut going to make the stud stick out any further.
Now if you're talking those wheels that take the 'shouldered' type lug nuts with no real taper on the wheel or nut but that instead rely on going all the way through the wheel and bottomong on the face of the hub, then definitely longer nuts would be needed to compensate for the greater spacing between wheel and hub that a shim would induce.
Last edited by Tifosi; 04-16-2009 at 07:21 PM.
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