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RE: oilheads-digest V4 #112


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,



-----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

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

>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.


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
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.
I have to put the spacer in, I'll sell the bike.

Hey, when are you coming to Simi?


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