Bolts anyone??

[Shoppinit]

Before and after photo would be great to see difference in stance if possible.

[Daveperc]

OK - final update. Got some 32mm bolts off Fleabay and have now got 5mm spacers all round.

If Shop is right and I end up with bad vibes I can always upgrade to 8mm or 10mm hubcentric later.

Afraid I haven't taken before/after pics - the extra width isn't that obvious anyway, and the reason for doing it was to avoid any more rubbing where Ol' Knobbly was.

Next project before it turns wet this autumn will be to decide whether to stick with GY F1 (which have been really good) or to try the PS4S - ah, decisions, decisions!!

Dave

[bam_bam]

Next project before it turns wet this autumn...

Where have you been?! The rainfall this week has been insane. Fucken hate this country sometimes.

[chunky79]

Next project before it turns wet this autumn...

Where have you been?! The rainfall this week has been insane. Fucken hate this country sometimes.

Our idea of wet and MrPercs idea of wet is a little different, remember his old C5?
And also, this country fucken hates you too sometimes.

[bam_bam]

* ,sometimes

[chunky79]

* ,sometimes

* all the time

[Shoppinit]

*, sometimes.

[Daveperc]

I hate it when Shop's proved right!!

Fitted the 5mm spacers at rear and got bad vibes around 80mph. Tried adjusting but no better

So have reverted to standard set up at rear for now and it's fine.

I think the rear spigot may be slightly shorter than at the front, and hence isn't quite long enough to centre the wheel properly - 5mm works OK on the front though.

I'm sure the load is transferred by friction generated by the tension in the bolts. The problem is that without proper engagement on the spigot the wheel is just a bit off centre.

Oh well, I live and learn!

Dave

[jockthedog]

This is my opinion as an Engineer.

The bolt itself is anchored in the threads of the hub. It does not wobble around.
The bolt HEAD is anchored inside the bolt hole of the wheel - either round or conical. No wobbling about in there (*)

Once 5 bolts are in and tight the wheel cannot move in any direction, so I think you may find that the spacer itself is the only thing NOT anchored by enough friction or anything else to the hub OR the wheel. Thanks to the holes in it being JUST bigger than the hub AND bolts.
I would say that the spacer itself is falling out of alignment with the hub and causing a mild vibe.
It's only a few grams of alum, but it's acting like a wheel weight.

Sound plausible?

(*) I have both 10mm spacers and WOBBLE bolts on my track car wet setup. The wheels are 5x114. I have banged those round the roads and track for years and not had any issues.
Mind you, the spacers do have a decent lip on them and the OZ wheels have big nylon spiggot rings too. I actually had to dremel those to fit together. No vibes at all, but I do use the star pattern someone else posted, with the wheels neutrally loaded, when I tighten the wobble bolts.

[jockthedog]

Agree, but it's not practical for most people to torque up a wheel in the air.

Lower/raise the jack till the tyre is JUST on the ground. Voila.

[bam_bam]

This is my opinion as an Engineer.

The bolt itself is anchored in the threads of the hub. It does not wobble around.
The bolt HEAD is anchored inside the bolt hole of the wheel - either round or conical. No wobbling about in there (*)

Once 5 bolts are in and tight the wheel cannot move in any direction, so I think you may find that the spacer itself is the only thing NOT anchored by enough friction or anything else to the hub OR the wheel. Thanks to the holes in it being JUST bigger than the hub AND bolts.
I would say that the spacer itself is falling out of alignment with the hub and causing a mild vibe.
It's only a few grams of alum, but it's acting like a wheel weight.

Sound plausible?

(*) I have both 10mm spacers and WOBBLE bolts on my track car wet setup. The wheels are 5x114. I have banged those round the roads and track for years and not had any issues.
Mind you, the spacers do have a decent lip on them and the OZ wheels have big nylon spiggot rings too. I actually had to dremel those to fit together. No vibes at all, but I do use the star pattern someone else posted, with the wheels neutrally loaded, when I tighten the wobble bolts.

But bolts don't center a wheel perfectly, the tolerances would have to be pretty amazing, ne? The hub bore should center the wheel, now when you chuck a spacer on without a decent lip in there, like a 5mm spacer, you lessen the hub center bore area that should center the wheel. Now, I don't remember if the OEM wheels have an inside chamfer like my aftermarket wheels, but if they did, this would create room for some slop, meaning it'd be pot luck to get a wheel torqued perfectly centered.
Or as you say, the spacer isn't centering, probably because 5mm spacers aren't generally hubcentric, either way, Ben has always maintained that a 5mm spacer shouldn't be used on the C5 RS, it should be a decent brand and 7mm hubcentric.
I'm not an engineer.

[Daveperc]

The problem is getting the wheel accurately centred.

It's not the spacer - that fits neatly over the hub and in any case is very low mass, and right in the middle, so low centrifugal effect.

The problem is that the inner face of the wheel, where it fits over the hub, is champhered and with the spacer on, doesn't full engage with the hub.

I tried the "wheel just off the ground" technique, but it is not sufficiently accurate - we're only talking about 0.5mm or so. Tried twice and although the wobble changed, it didn't hugely improve.

I think the answer is simple - Shop was right, you need 10mm hubcentric spacers at the rear!

Bother!!

Dave

[bam_bam]

I think 7mm hubcentric spacers have been found to work. I think I've got those on the rear of mine.

[jockthedog]

It appears that we are ALL correct, depending on whether the wheels are aftermarket....

http://www.nissantechnicianinfo.mobi/ht ... ntric.html

Very good wee description.

[Shoppinit]

Yes, we are all winners.