I've been holding off on posting in this thread because my bike has spent the last 2.5 wks at my dealer for this problem, and I just heard from my Service Manager (who is a great guy, and after he rode my bike, said something along the lines of "wow -- well, Mark, I can't call you crazy (to which I responded "well at least not on this"
) -- it really pulls; I'll see what NA has to say."
At the time I took my bike in, BMWNA apparently stated that they had only heard of *one* other case of this issue
huh
. On the other hand, we all are starting to hear of quite a few bikes with varying degrees to "pull." It also appears that this is a more common problem than I had hoped, as 2-3 other K16s currently in my dealer's shop *all* have at least a light left pull.
My bike's pull I believe is on the "more" end of the spectrum, and will have to be addressed one way or the other, as several hours of having to constantly maintain a moderate countersteering pressure in order to keep the bike from veering off the road is totally unacceptable -- BTDT (see below) and the resulting arm/shoulder/back cramps from maintaining the pressure on long rides was/is impossible to "just live with."
A bit of background, and a couple comments on posts above:
It's very likely not a problem that can be fixed.
That's what they said about my hard-right pulling 1999 R1100RT.
Actually, what the regional rep wrote at the time was "Bike pulls right when hands are removed from bars. Don't remove hands from bars" -- that was an UNBELIEVABLY galling, infuriating and insulting statement !!!!! A bike which requires constant, cramp-producing countersteering pressure to avoid veering off the road is NOT a "normal" or "acceptable" bike -- whether or not hands are on the bars!
So faced with an "incurable" problem and the associated muscle cramps it was causing by having to maintain a constant countersteer to go straight, I decided I'd take a shot at curing the incurable problem.
On the R1100/1150RT, the right swingarm pivot is fixed, and the left pivot bolt is used to set the desired bearing pre-load. A bit of back of the envelope calculation said that moving my RT's swingarm 2 mm to the right should put the tires in proper alignment. After removing the right swing arm pivot (a WITCH of a job that took several hours -- long story), a large, 2 mm-thick washer was installed under the head of the right pivot bolt, spacing the pivot 2 mm to the right and thereby allowing the left pivot bolt to move the swingarm 2 mm to the right. Took the bike out for a ride and -- whaddayaknow -- straight down the road with no hands.
The point of recounting the above is not to suggest I'm a genius or magician -- I'm just another customer that knows which end of the screwdriver to hold. The point is that there was no reason why a solution could not be found if someone wanted to do so back then, and the same holds true today.
Quick question for the "straight as an arrow guys." Do you ride with your hands off of the bars? Because what I'm describing is a very weak effect and you wouldn't notice it even with a couple of fingers holding one grip. You gotta let go.
Different degrees on different bikes -- my pull is readily evident whether hands are on or off the bars. Overloading the right saddlebag and literally hanging my tail out to the right is needed to put enough weight over to the right to noticably counter the pull.
(BTW, before anyone says it, this is not an issue with road crown, the pull is either bad with one direction of road crown, or it's worse with the opposite road crown).
Good point. Which way does the driveshaft rotate. It's possible the counter torque from the engine into the frame causes it to lean to the left. It this is true then when you let off the throttle it should turn right?
No -- the shaft may turn in one direction, but their are reaction forces at the other end as well, and the primary force at the crown wheel is a tangentially-oriented downward force (with light reaction forces as the tapered gears try to laterally separate). There is nothing from the shaft which could influence the bike's steering direction (unless the application of torque was enough to cause the rear wheel to toe left or right a lot as the drive torque is applied -- something that should be plainly visible as bearing play with 9-3 o'clock rear wheel rocking).
Bloody thing pulls to the left: after riding straight as an arrow in my K12GT, back to the bad old days of both my RT's which pulled left.
So how can this be fixed, does anyone at BMW care?
Does BMWNA care? Yeah, I believe they do, as they are obviously smart enough to realize that significant bike-class-type problems (like the last decade's final drive problems) are very damaging to BMW's reputation and result in lost sales.
That said, BMW AG and NA have loooong been known for absolutely not providing information on problems
, even when they are plainly aware of them and are working to fix them (for example, during the FD problem era, failed FD's were being shipped back to AG for analysis, but we customers were never given an iota of information as to what they found).
The driveshaft rotates to the right, to turn the rear wheel forward, so yep that would twist the bike over to the left.
Sorry, nope -- visualize this as a free body diagram -- for the shaft to be applying a force (torque) to the crown gear, the other end has to have a corresponding reaction force (torque) -- and the force at the FD crown gear is tangentially downward, not a torque about the longitudinal axis -- the mere fact that a torque is being apllied to a shaft about its axis of rotation does not mean the axis is aligned in the right manner to cause the bike to rotate as postulated (in this case, there's no net rotational force about the yaw axis which can result from the shaft's rotation, nor a rotation about the tires' foot prints to rotate the bike over).
Trying the no hands in neutral gives me no pull. but mine does pull left. As i said above, ill just put the tools in the right bag and roll with it.
Alas, I can't put enough weight in the saddlebag to completely offset my pull.
And in any event, why should I have to lose most/all of the space in a saddlebag, and have to tote around a big bike-slowing, handling-effecting lump in a saddlebag, in order to get the bike to ride in a straight line??????? To accept that as "normal" or "ok" is wrong.
If we were to contact BMW I am pretty certain they would ask why we have our hands off of the handlebars anyway,
See their response 12 years ago, above!
SO, as of this afternoon, I need to decide whether I want to go to the trouble of investigating and attempting to fix this problem by myself again, or whether I want to start the process with the aim of ultimately forcing a bike buy-back.
This does not look like it will be as simple an issue to fix as my R11RT, as I've already looked, and there does not appear to be any room left to move the swingarm to the left before it contacts the inside of the main frame (with a left pull, either the rear wheel needs to move to the left, or the front wheel needs to be moved to the right).
I'll be poking about the front of the bike next -- Duolever A-arm mounting mods? mismachined or misassembled main frame at the swingarm pivots? other? Dunno -- have to decide whether I want to deal with an issue I should have to be dealing with in the first place.
