shimectomy

[Joe Kiefer <kiejo@xxxxxxxxxx>]

My 2000 RT has had PTTR from day one.  It will climb any crown in the road if
I drive on the left side.  No dealers will acknoledge the problem and I was
even given a document (bogus I believe) by one dealer from BMWNA that says it
is normal because of teeh bike's design.  I will never believe in a million
years that BMW engineers can't design a bike that goes straight.  There are
probably old threads on this forum with my complaints of seven years ago.
What bugs me is that not all RTs do this.  Just like not all RTs surge as mine
has never done.  I was aware of the shimectomy approach but elected to leave
the bike as-is and suffer the pull and uneven wear on the left side of the
front tire which I have done for 38K miles now.  Has anyone out there tried to
fix PTTR using Computrack (http://www.gmdcomputrack.com/)?

Joe


-----
Original Message ----
From: oilheads-digest <oilheads@xxxxxxxxx>
To:
oilheads-digest@xxxxxxxxx
Sent: Friday, October 5, 2007 3:47:03 AM
Subject:
oilheads-digest V4 #115


oilheads-digest        Friday, October 5 2007
Volume 04 : Number 115



In this issue:

    RE: oilheads-digest V4 #112
----------------------------------------------------------------------

Date:
Thu, 4 Oct 2007 14:03:17 -0700
From: "Bob Covey" <Covey@xxxxxxxxxxxx>
Subject:
RE: oilheads-digest V4 #112

Bob,

Interesting. As soon as i get my RT back
together I will pull the bags, take a
test ride and see what conclusions I can
draw, too. Despite the weight in the
left bag and the missing spacer, mine
won't run hands-off, but it doesn't dive
to the right the way it once did and
compensating for the remaining pull isn't
causing me physical issues, so it
must be close.

Enjoy your trip,

Cheers,

Bob

- -----Original Message-----
From: Robert Silas [mailto:robert.silas@xxxxxxxxxxxx]
Sent: Tuesday, October
02, 2007 6:15 PM
To: Bob Covey; Mick
Cc: oilheads@xxxxxxxxx
Subject: Re:
oilheads-digest V4 #112


To: Bob Convey

Bob,
I machined off 6 mm from the
wheel's hub and left the spacer off. The
interference happened between the
spokes and the brake calliper. I have two
rear rims so I am experimenting with
one. Because of the interference I had
to replace the spacer. Even in this
situation I moved the rear wheel closer
to the drive unit by 6 mm, relative to
it's position when left the factory.
The bike is almost perfect. I still need
to remove the shim.
I am not just guessing. I have a couple of engineering
degrees and 53 years
spent in engineering design, not on this subject though,
but it gives you a
certain way to approach a problem. Moving the wheel towards
the drive unit
is based some rough calculations which indicated that the wheel
should be
moved by 8 mm.
Regarding the center of the bike, which I consider
also the center of the
front wheel, the rear wheel is now 9.5 mm offset into
the "minus direction".
There are a lot more to my measurements that I am
mentioning here and I am
not finished until my RS will run straight, hands
off, without the system
cases, just like my '79 CX500, '84 Shadow500 and the
'84 Nighthawke650, all
drive-shaft driven bikes.
I am leaving tomorrow for 3
weeks so I cannot go into too many details.
As far as friction goes, in
structural engineering we bolt heavy steel
structures with high-streght bolts
without any shims in between members. The
shim provided by BMW is a slippery
stainles steel, though having a bit of a
rough surface. If it works for extra
friction between aluminium and steel
.... I cannot say, I have no experience
with this combination.
I just ordered a used rear calliper to have one to take
apart and measure
the thickness of the material, it might be possible to mill
off a bit from
it's back. I know cases that this had been done, not on BMWs.
I
respect anybody's opinion, I do not want to start a thread, so I may
contact
you off-list.
More on my return.
Bob Silas


- ----- Original Message -----
From: Bob Covey
To: Mick
Cc: oilheads@xxxxxxxxx
Sent: Tuesday, October 02,
2007 1:07 PM
Subject: RE: oilheads-digest V4 #112


>Mick,
>
>I took the
spacer out of mine 60K ago to attempt to address a severe PTTR
>problem. It
certainly helped. packing all the heavy stuff in the left I
>haven't
experienced any problems that I know of, what am I missing?

There was a court
case where someone's rear wheel fell off and he had
removed the spacer.  From
what Paul Glaves says, that spacer is actually
a 'friction' device and it
increases the clamping force on the rear
wheel to hub.

Mick

Hmmm, I
certainly don't have your or Paul's experience. I faithfully torque
the the
lug nuts, dry and clean. Judging from what it takes to break them
free, they
aren't moving at all. I think I'll leave the spacer out until I
get
some
indication that it is a bad idea on MY bike. Others can make their own
decisions. My hand, shoulder and elbow issues mean that I couldn't ride any
distance with the spacer in. I was ready to take the plane home from Bend.
If
I have to put the spacer in, I'll sell the bike.

Hey, when are you coming to
Simi?

Bob


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------------------------------

End of oilheads-digest V4
#115
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