Custom wheel specs

[TRS6]

Hey Guys,

I am in the process of pulling the trigger on a custom order of HRE 21's for my RS6.

I am getting conflicting information in relation to the perfect offsets and widths with stories that a 10.5 width will be cause for mass understeer at speed.

The specs i am working with are as follows:

21x10.5 ET20 Squared.

Anyone have any real world experience and or advice here as I am very hesitant in dropping the serious coin required for bespoke HRE before getting the setup just right.

Appreciated.

[zeshark]

I'd stick with stock dims. This business of "pulling" tires with wider than specified rims is utter nonsense to me, especially with low side walls. You have then entire freedom to play with moderation with spacers and ride height. Rubbing should never be in the cars for a car that price, I'd leave that to tuned mk3 GTIs.

Which HRE design are you going for ?
They are so freaking desirable, but I am haunted by the fear of kerbing rims, a likelier prospect for a daily driver where you don't always choose where you have to go.

Sent from my Nexus 10 using Tapatalk

[RS6chris!]

Stock rims are crap and bend

Go aftermarket or custom made

Loads of options in different offsets and widths

Ideally you want 21"x 10.5"....OEM tyres fit fine, Dunlop SP max or Michelin PS will give best fitment and not stretch sidewall.

Adjust offset using Spacers

Never had any "understeer" or rubbing issues on my two C7 using different set ups and wheels.

[TRS6]

Im with you Chris..

Going 21x10.5 as the stock wheels are heavy and buckle too easily! PE edition wheels that is

I am aiming to achieve max concave whilst clearing front ceramic calipers.

Current suggestions from HRE are not to run anything wider than a 10 inch upfront as it apparently is cause for mass understeer at higher speeds.

[RS6chris!]

My set up.....

[RS6chris!]

Ispiri ISR6

21 x 10.5 offset 30

20mm rear Spacers
15mm front Spacers

No rubbing or issues at all

Pirelli p zero (although I feel a little stretched that's why I recommend Dunlop or Michelin)

[TRS6]

Nice Chris!

So zero turn in issues etc with that width on the front?

I am hoping by running a lower offset somewhere between +17et to +22et I can achieve more concave/angle on the wheel, however not compromise with caliper clearances.

But yes I am confused as to why HRE are claiming huge issues with 10.5 fitment on the front? They wont warrant it.

Here is what they've said:

"10.5 front won’t fit according to my data.
94467 and 90206 ran 10.5 fronts but I don’t know what they did to make it work.
Expride (Japanese distributor) ran some 11” front/rear setups as well –needed modification on the vehicle
There is probably more room made available after lowering that the measurements we have did not account for"

[RS6chris!]

Deffo no turn in issues

I'm in a what's app group where most of the boys are runnng 10.5 width wheels....no one has issues....most run Spacers too

However...most haven't ceramic calipers....I have and again no issues...remember rear calipers are same size whether Steels or ceramics...


Of course I can't commmet on other widths etc...but 21"x 10.5" seems to be the sweet spot for non OEM wheels

[zeshark]

I really don't get it: in what world are 285/30, designed to run and work on 9.5", going to perform as they should with an inch of excess in width ?
Not even mentionning the absence of rim protection offered by the tire.

It may not rub, it may look good, but i'd be surprised if a tire or chassis engineer would not consider that as utter nonsenese.

Same thing with running thicker spacers at the rear. It is a recipe for understeer. Looks vs functionality.

To each their own in terms of what they want to prioritize, but it sounds like questionable advice to me.

[MikeFish]

Thanks Zeshark, we've heard your opinion and are ignoring it. In what world is 285 a stretch on a 10.5" width rim? 285 is too wide to fit on a 9.5" rim, it is perfect for a 10.5" rim. And if you actually look at such a combination on the flesh you will see it still offers rim protection.

[MikeFish]

[wildbore]

Hmm, according to that table, my 21" wheels, supplied by Audi and which are 9.5" wide, shouldn't have 285 tyres fitted to them...

Not totally convinced by that app.

[MikeFish]

Chris is talking from actual experience and says there is no negative impact. I also know a lot of people running this wheel / tyre size with no negative effects so I'd say it is your opinion that sounds like questionable advice in this instance and with no actual experience to back it up.

[MikeFish]

Hmm, according to that table, my 21" wheels, supplied by Audi and which are 9.5" wide, shouldn't have 285 tyres fitted to them...

Not totally convinced by that app.

285mm is nearly 11 1/4 inches. Sounds about right to me.

[zeshark]

Thanks Zeshark, we've heard your opinion and are ignoring it. In what world is 285 a stretch on a 10.5" width rim? 285 is too wide to fit on a 9.5" rim, it is perfect for a 10.5" rim. And if you actually look at such a combination on the flesh you will see it still offers rim protection.

It is not my opinion, it is the opinion of the engineers who signed off that chassis.

The two dimensions sanctionned by Audi for the RS6 Performance are:
275/35 R20, 9.5xJ20 offset 21, H5U
285/30 R21, 9.5Jx21 offset 25, H5X

If I have to choose, I'd venture to say that the boffins that work hand-in-hand with the tire manufacturers and approve the Audi sanctionned tire executions (R0x) are those who know.
You may be in that specific line of work and know better. I am not and my MS in engineering tells me that staying within manufacturer specs is never a bad idea.

Now, if you claim that 9.5" is actually too narrow for 285 tires, this takes us in different territory.