[e//S2] brakes/hubs

[Jimmy Pribble]

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> I didn't think the S2 and urS4 used the same front wheel bearings... else
the 5-bolt conversion would be more common.

Both use 82mm front wheel bearings.  However, the rear UrS4 rear wheel
bearings are also 82mm, while the CQ/S2 is only 75mm.  AFAIK, there is no
other 5-bolt hub solution for the CQ rear other than the S2.  That is what
continues to keep the conversion uncommon.

> I think the difference in offset is  4mm, not 2mm (and Brandon's bracket
was offset 3mm in the BIRA kit)...

Yes, I noticed after I posted that I forgot my little "about" tilda (~).  We
didn't measure the exact difference in hub depth, because we didn't have an
UrS4 hub off the car at the time, so we didn't think about it.  Between all
of us, I think we should have the parts and can get an exact measurement and
post it up.

You make some good comments about brake brackets and spacers, but I need to
check my notes before I repost.  I wasn't sure about the radial difference.
I thought both UrS4 and CQ used same caliper and 276mm rotor, only with a
different rotor offset.  While the UrS4 had a thicker hub, its brakes had a
deeper hat (higher offset) than the CQ/S2.  Anyway, me gets confused!  Let
me gather my notes and we'll regroup.

Jimmy


-----Original Message-----
From: Miller, Chris [mailto:chris.miller at infofoundry.com]
Sent: Thursday, May 01, 2003 11:48 AM
To: Jimmy Pribble
Subject: RE: [e//S2] brakes/hubs


I've seen your photos.  I didn't think the S2 and urS4 used the same front
wheel bearings... else the 5-bolt conversion would be more common.
I think the difference in offset is  4mm, not 2mm (and Brandon's bracket was
offset 3mm in the BIRA kit), and I do have both off the car right now; I
think the S4 hubs and S2 hubs are the same thickness (the part with the
holes for the wheel bolts are, anyways), but the mounting locations for the
bracket may differ.  My hubs from the 200 are either urS4 or V8, same part.
New from the dealer or junkyard, those are pretty pricey, btw...

I've got a photo kicking around somewhere of the urS4 hub; it might have
total height measurements on it...

The S2 versus urS4 mounting locations are also off radially, so your spacer
might not be enough; the pads will ride a bit lower on the rotor than they
did on the S4 (2.5 mm?).  Either that or a second pair of spacers between
the caliper and the bracket are needed.

-----Original Message-----
From: Jimmy Pribble [mailto:Jimmy at texasbankers.com]
Sent: Thursday, May 01, 2003 12:04 PM
To: Miller, Chris; es2 at audifans.com
Subject: RE: [e//S2] brakes/hubs



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> CM > I've got a BIRA System 2 kit off my 200 using my2000 S4 rotors and a
Porsche monoblock caliper, but the 200/urS4/urS6 mounting points are off a
few millimeters in diameter and depth, so that bracket won't work.  A
modified version of this system has been designed, and Brandon Hull uses it.

Here is a cut-n-paste of a message that I just sent out to a fella a few
days ago:

"These are great questions, and you have inspired me to improve my hub
conversion page sometime soon, because it is a little thin.

Here is the deal: The UrS4 hubs are thicker than the S2 hubs, so if you use
the UrS4 hubs for the front of your CQ, your brakes should carry over.  But,
if you use S2 front hubs, you will need to use spacers (2mm) to push the
brake carrier out in order to use the brakes.  That is what I had to do when
I moved my big brake kit.  Unfortunately, we never had both hubs off the
cars at the same time, so we never got a comparison photo.  Maybe someday.

Anyway, because of the nice brake kit options available for the UrS4
(especially the RS2/BR/S8 "kit" you mentioned), I learned too late that the
UrS4 hubs would have made more sense on the CQ.  Now, in order to not use
spacers (which worked fine, but I fundamentally don't like them), I will
have to have a custom bracket made.  If you already have committed to S2
front hubs, or if you just want more information on brake kits available for
the S2, you might try Alex at Europrice (www.euro-audi-parts.com).  I think
he may have a kit specifically for the S2.  BIRA also has an S2 kit."

Otherwise, I recommend using UrS4 front hubs.  Besides, they should be more
widely available.  Now, I don't know if there is any difference wrt 200
hubs, so be careful.

I haven't updated this FAQ yet, but here is the address to my 5-bolt
conversion page:
http://www.urs4.com/logbook/RS2CQ/s2hub/s2hub.htm
<http://www.urs4.com/logbook/RS2CQ/s2hub/s2hub.htm>

Jimmy P.