| Author | Message | ||
     F_skinner |
Here is the thread. http://www.badweatherbikers.com/buell/messages/476 23/593314.html?1285011736 I have 9 tie bars ( 3 brand new and 6 from other bikes) and only two are the same (a third one was close to the other two) I have a feeling that they are set to each frame from BMC since each frame can have minor variations. I thought buying a few from the dealer should give me the correct length but no such luck. They come very loose and I quickly got them out of wack. Does any know how they did the adjustments at the factory or have a theory? I am not so sure it is just tire alignment as that does not make much since to me (I am not an engineer) save the rear tie bar which would have the most effect. I think it is more motor alignment and stress for the motor in the frame. If I can get the motor aligned correctly in the frame the rest will fall in line. In my mind after the rear swingarm block, isolators and plates and the front motor mount and isolator is installed it will be close enough to take measurements of the motor in relation to the frame then adjust the tie bars accordingly. Anyone have any suggestions or ideas? Frank | ||
| Ebutch |
Frank:I I agree. Think they where just centered on frame at factory being assembled.My two cents.Being no stress both ways.I,m going to add front iso. Tie bar this winter to my S2T.  | ||
| Gowindward |
"If I can get the motor aligned correctly in the frame the rest will fall in line. In my mind after the rear swingarm block, isolators and plates and the front motor mount and isolator is installed it will be close enough to take measurements of the motor in relation to the frame then adjust the tie bars accordingly." What would be your reference for knowing if the motor is aligned in the frame? Since it is suspended on rubber mounts. If the motor CG is off to one side of the center line, which it probably is, then the motor will have a tilt left or right. It may be a small tilt but still there. I would be more inclined to pull a known tie bar from bike and copy it. Sure a pain, but hey you do have a garage full of tubers to copy from....LOL Loren | ||
| F_skinner |
I have been thinking about this, all I would need is a flat surface and the motor in the proper position. As a frame of reference I can use one of the other bikes but I would have to use the frame to motor distance as a reference. Correct? (I am not an engineer) If I use that reference it could be off if the frames are not exact. After that all I really need to know is the torque value of the tie bars. I am guessing around 30 ft pounds. I am not so sure the rubber will not hold it straight but if I have the motor supported It would naturally want to be lined up if the front and rear are mounted correctly. I already have a couple set that way. What if the the frame dimensions are different? BTW: the tie bars on one S2T are slightly different than the length on my other S2T. I am convinced that the tie bars have to be set to the bike they are on. However, maybe the distance is not as critical as I am making it out to be. I was hoping 1313 would have time to post up. I am no big rush as I am still building the motor. (I am not an engineer) | ||
| F_skinner |
I think I understand how the tire alignment can be used. I am not sure so shoot holes in this and let me know if I am off. (I am not an engineer) The isolators just connect the frame to the engine as well as the swingarm to the rear suspension assembly. The bolts just anchor the isolators to the engine and swingarm. I think this is a good reference point but I am not sure how I would measure to determine alignment. I would have to get the rear wheel perfectly aligned. Then use a straight-edge along each side of the rear wheel as someone pointed out. From that I could determine how the front wheel is centered in relation to the rear. I think the front tie bar can be used to center the front wheel and the rear tiebar for the rear wheel (although I think the rear should be easier for some reason). I think I will need to make some type of adjustment tool. I think the top tiebar (the one near the top of the motor) would only adjust the camber (is camber the correct word? I am trying to say the top and bottom of the bike is lined up). If I had the motor in the frame and disconnected everything that supports the motor save the top tie bar the motor would want to move to the left (as sitting on the bike) because that is were the motor weighs the most. (I think). It would seem to be that this would allow me to adjust vertical alignment. I have no idea on how to do that but it would seem that I would have to use two points on the bike. I am not sure. If I can freely support the motor and put the frame on it would it not be aligned with no weight to bend the frame or throw the wheels out? I am wondering if I build a motor stand, place the frame over the motor then add the tie bars it would be straight when weight is applied. Of course that is much easier said than done (the rear swingarm block weighs a lot and it would be very cumbersome... I am thinking that over time these things will work themselves out of alignment anyway (and go through a lot of isolators) I may be over thinking this. | ||
| Gowindward |
Reading Material http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PT O1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-b ool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN% 2F4776423 | ||
| F_skinner |
Don't try to learn me Loren...  Thanks for the link... I understand it a little better now. | ||
| Gowindward |
Really this is all about swingarm to steering head alignment and the tie bars control that alignment through the motor. Mount motor and swingarm up to frame. An 8' long rod through the swingarm with equal amounts extending beyond the swingarm sides. A long rod through the steering head. Start measuring from one side to the next, adjusting tie bars until opposite sides are equal. The long rods help multiple the variation for measuring. | ||
| F_skinner |
Yes, that was what I was thinking. I am going to do a test run on my other bikes to see how far out they are or if they are spot on. | ||
| Gowindward |
A picture being worth a 1000 words.  | ||
| Buellistic |
How come that was not put in the FACTORY SERVICE MANUAL ??? "SORRY" but "i" have not had a reason to think about this one ... "BUT" if you can think out of the box, it should be quite easy ... Did check my wheels early on and they were tracking correctly so "i" did not go any farther ... | ||
| F_skinner |
Thanks Loren... I got it... It should be easy enough. LaFayette, it is in the factory service manual, it says "do not adjust" LOL... Frank | ||
| Gowindward |
You see some of that "Staff Engineer" title wore off on you. | ||
| F_skinner |
I successfully resisted any engineering knowledge.  | ||
| Buellistic |
It also says NO NOT REMOVE THE FRONT MOTOR MOUNT FROM THE FRONT HEAD ??? | ||
| F_skinner |
Yes it does...  | ||
| Gowindward |
Oh sure you did....you have to have a bit of the "knack" in you or you wouldn't be working on motorbikes. | ||
| Buellbozo |
May I humbly suggest that yes, the object is perfect alignment in both axis from swingarm pivot to steering neck. Prehaps, using the extension method cited by Loren, this may be a great opportunity to run down to Loew's and pick up one of those nifty new laser pointer/protactor, levelling gizmos. That you've been wanting anyhow. In olden times, we used a broomstick and string for initial setup on newly rebuilt Commandos. Just a thought. |
