Bike goes to the right when ya let go of the bars...

[TaosBrick]

Hmm... My idea is that this situation could be as much a result of the frame being tweeked to one side or the other, in addition to the aforementioned offset.
Thus, in comparison to the the headset, the engine/tranny/swingarm is at an angle, and with as I say, my limited understanding of geometry and physics, I would then hazard that the swingarm/final drive/rear wheel is cocked right of frame/headset centre line, thus causing the rear wheel to be pointed to the left, which then causes the bike to drift right.
  When I can actually not be RIDING the thing, or doing the other stuf I am doing on this trip, I will apply the string method to see what's what and report back...

[mystic red]

To add to the mix, I have a RS wheel mounted to my LT which offsets the rear visibly and it does nothing to the handling or tire wear. I would look elsewhere.

[TrueAce]

Another perspective would be this: imagine a normal rear wheel on a vertical axis at 12o'clock. But a slight imperceptible twist to the rear frame rails positions the wheel at 11:50, or even 12:10, now you will have "push" forces affecting the front end and unequal forces on the driving tire, and the front end.

[kennybobby]

The frame is very simple and flexible--just some mild steel tubes welded to a central tube.  Any drop or wreck can tweak or twist the frame tubes or forks and cause the front wheel to be clocked.  It is easy to twist back if need be, just loosen the mounting bolts and get a long lever arm to put it where you want it.

i have made notes on hundreds of bikes at rallys to notice their tire wear pattern to determine that this was a design flaw before i started cutting metal--it was the only solution that made the bike track straight.  Look at that big honking piece of aluminum on the head frame mount--there's plenty of extra metal there that likely should have been milled at the factory. 

The other thing i could found was some old technical documents where the clever germans calculated that the engine rotation would generate a torque and so they designed an intentional offset in the wheels to counteract this.  Too bad they didn't test that theory before going into production.  Funny that there is NO other motorsickle builder that sees a need to have offset wheels.

some folks are more sensitive to suspension and handling issues than others, one of my super powers is hyper-sense for it and can jump on any bike and tell instantly if the handling is correct or not.  And i'm just stubborn enough to want to get to the root cause and fix any problems i try to solve--just like my brother Ricky...

[TrueAce]

You da MAN, KennyBobby! Too bad we don't have a frame fig figured out for checking spec on these K's. Bet one could be figured out.

[Martin]

I have tried to get all the alignment figures on the net, couldn't find them. I know there are books for all the alignment figures for cars when they put them on the aligner jigs. So they must be available somewhere, I tried the local bike smash repair shop but they are not open on weekends, so I will try them Monday. I was going to try the local BMW dealer but I don't think they will cooperate. Does anybody have a dealer that may give them the figures.
Regards Martin.

[kennybobby]

Howdy Martin and Ace,

i added some screenshots from the factory service manual for the frame tightening sequence and shim placement, shim part numbers from the catalog, measuring wheel offset, checking the frame, etc. to my previous post, here. 

The fixture for checking offset is shown in one of the diagrams, the frame-check fixture is also something that a good dealer would have in the tool room, but i've never actually seen one--although i've asked at several places.

i used a lathe to turn my own set of shims with up to 10mm thickness--tried them in various locations but it only made the offset worse.

[Martin]

Thanks for the post saved me a trip on Monday. I'm lucky my bike tracks in a straight line and my tyres wear evenly.
Regards Martin.

[TaosBrick]

Ah yes - now this occurs to me. Will all the folks who a lurking/posting on this thread that have K's which track STRAIGHT please chime in? I simply cannot believe that they ALL drift to the right.

[Elipten]

Mine tracks straight. I looked at buying one that had the tires worn on one side. So I walked away


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[Scott_]

It's hard to tell about the straight tracking for me as I don't really have any absolutely "flat" roads around me. They all have some crown to them.
Either way, my tire wear is even on both bikes.

[rbm]

My K75 tracks straight as well.  No tire wear anomalies.

[mystic red]

The Fire Truck is on rails.... despite a noticeable offset.

[kennybobby]

Hey all you straight and narrow trackers--are you setting the throttle lock and going no-hands on the bars?  That is the test for comparison, he is not asking about if it tracks straight when you are steering it.  Go find a stretch of road and do the test.

[mystic red]

C'mon...... Throttle lock is so 20th century... Cruise control and I'm on rails.
The real story here is will I get to 3000 posts before Ichiro gets to 3000 hits?

[Martin]

Homemade throttle lock set, hands off bars, standing on seat juggling chainsaws, tracks straight.  :2thumbup:
Regards Martin.

[The Dude]

When I ride mine,especially doing a selfie,like in Taos' avatar ,Moto falls to the the right.Just a knee push on the tank and it's back straight.No uneven tyre wear,that I can notice.

[Laitch]

That is the test you must do, this is not asking about if it tracks straight when you are steering it. 

That isn't a test I must do, kennybobby. Based on TaosBrick's first post, he's asking the rest of us if it takes effort to steer it in a straight line. His question is about effort.

It doesn't take any particular effort for me to keep my bike tracking straight. Its tires wear evenly. Obsession about its tracking straight when I'm not lightly controlling its handlebar isn't on my program nor is perfectly balancing the weight in all my gear pockets, side cases and tank bag.

Thanks for the link to the frame alignment rig and procedures, and thanks to Gryph for linking to the manual with the section on frame shimming.

[TaosBrick]

In light of many of the replies I see here, I am thinking that the 'factory offset' is Not what is making my bike and others drift right. There is some other kind of tweak-age going on here that would seem to me to be frame or fork related. In my case, I strongly suspect the frame.
  Once again, I will not be able to check this until I get home. At least fresh rubber on the rear and both tyres balanced has restored my Brick's legendary smooooooothness, and made it so that the drift to the righ is a bit more tolerable. Good news for the 1,300 mile slab home.

[tsnap]

Did you run a carfax on the VIN?  Someone here may have free access to the service.  It would tell you if there has ever been a reported incident on the bike.

tom, who knows so little. :tinhat2

[Laitch]

There is some other kind of tweak-age going on here that would seem to me to be frame or fork related. In my case, I strongly suspect the frame.

In the K75 section of Bert Vogel's compilation of service bulletins accessible by a link in the Workshop here, there is this description of a simplified check for frame damage.

[TaosBrick]

Cool! Will add this to the string check when I get home.

[richarddacat]

Mine will pull to the right so you are not alone. 

Slight pressure on the left peg will keep it straight enough to throw a glove on or for whatever reason I have for my hands to be off the bars.

[kennybobby]

In the K75 section of Herb Vogel's compilation of service bulletins accessible by a link in the Workshop here

Is there a sticky thread of these bulletins, or where is this link in the Workshop?  Thanks, kb

[Laitch]

Is there a sticky thread of these bulletins, or where is this link in the Workshop?  Thanks, kb

Go to the Motobrick Wrenching section, kennybobbly. You almost can't miss it.