hi, new to forum, but have a problem

[ovanman]

hi, I've bought myself a 1984, K100RT , it's a bit shabby but that's OK. the problem is that I'd exchanged cash and ridden the bike home before i noticed that the rear wheel doesn't line up with the frame. the bike rides well, doesn't crab at all, handles well. I've spoken to the seller, who claims he always thought the Misalignment was down to the fiberglass mudguard being out, but as you can see from the pictures that's not the case. i can only think that the frame is twisted, there's no obvious damage that i can see and the wheels seem in line with one another. so I'm thinking, should i replace the frame, and if so, does anyone have suggestions which one will fit?, are all K100 frames the same?
thanks in advance

[Scott_]

The only tip that I have at the moment is be wary of replacing the frame.
Not that you can't, but you may have MOT or title issues as the title is registered to the number stamped in the frame.......
I have seen in a BMW manual or memo, there is a table of measurements(and procedure) for the frame to determine if it's straight or not.
I can't remember if it was online or in a printed book. Old timers setting in......

[billday]

Have you taken the wheel off? My '85 K100 has a shim that goes between the final drive and the wheel -- your bike looks like it's got 2 or 3 shims in there, or a shim that's too thick. Also, while the wheel is off, tug on the swing arm in every direction to make sure there's no play in it. Very unlikely your problem is the frame.

[Chaos]

It does look offset to the left,  maybe too many shims?  I think a little offset is normal (5-10mm) but I forget which way it is offset.  One quick and dirty way to check for frame damage is to loosen the enginetranny mount points and see that all the holes still line up with the bolts out.  I agree, a bent frame is very unlikely.

[ovanman]

hi, I've had the rear wheel off and there are two shims there. i spoke to the previous owner about it and he says he was told to put the second one there by the MOT garage, as the wheels were out of line. which sounds a little odd. I've taken the shim out and the offset looks better but not great. I'm going to try loosening the engine/tyranny mounting bolts to see if i can discover anything. I'm thinking perhaps the shims there maybe wrong and that is throwing the rest of the bike out. its a plan. I'll post updates

[Opus]

Is it me or is the side stand mounted on the right side of the bike? I thought that they were always mounted on the left side.  :dunno

[Grim]

Is it me or is the side stand mounted on the right side of the bike? I thought that they were always mounted on the left side.  :dunno

They do drive on the other side of the road. If you think about it when parallel parking that would have to dismounting on the curb side.  Wonder if the steering locks opposite of ours?
That would be an interesting conversation piece on a US bike and take care of the blue burp at start up.

The engine is a stressed member meaning its part of the frame. There is a few MM of offset built in but its almost not noticeable visually but looking at your bike...DAMN! that dont look right.
 Some where in if you do a internet search you will find what is in spec.

A lot of people remove the shim to get it to track better so the fact they have added one is suspect that somebody knew there was an issue with this bike.

Id start by finding a couple straight items longer then the wheel base and laying them on either side of the bike tight up to the rear tire spaced about 10-15 cm above the ground and see what the measurement is to the front wheel on either side. This can also be done with some string. There is description under the suspension section (the second one farther down) here:
http://www.ibmwr.org/ktech.shtml
Thats going to tell you if its tracking straight. If its not tracking then either you have an issue with the swing arm or head tube is out of line. If it is tracking straight then the frame is bent on the rear portion.

Swing arm could be bearing issues. Have to take it apart and see If there is any bearing damage.

Everything back there is alloy so I think the swing arm would break before bending but I may be wrong.

I'd also pull off the seat, tail, tank and inner fairing panels if not the full fairing and give the frame a good looking over for points of impact or repair attempts. If the frame is bent sometimes (Not always) the paint will crack at the bend in sort of a radial pattern. This will give you an idea what to look for. http://www.mytenspeeds.com/My_TenSpeeds_1/HowToDoIt/FrameDamage/FD_Norco/FD_Norco_Forks_2.jpg

Hope that helps you figure it out.

[CRASH]

I can't find a wheel track offset spec for your era bike, but the more recent K bikes (1200s) could have an offset of 14mm and still be "in spec". (-5mm to +14mm)  I suspect the older K bikes are similar.

The newer K bikes track is NOT in line from the factory, apparently on purpose. The MOT guy doesn't know BMWs if he is saying that the tires have to be in line. Does it pull one way or the other?How far off is it?  Check it against the front tire, not the frame. If you do not have a long straight edge, careful use of string can help you sort it out. It is best to go from the rim (assuming it is straight) but you can at least get a ballpark figure from the tire edges.

Yours looks way out, in that picture, but check the track first and then you can figure out if it is something else (frame etc.)

[Scott_]

The 1100's have a track offset spec of 12mm.

[ovanman]

    I've had the bike down to the frame specialists and they've confirmed that the frame is bent, however to put it right is going to cost half as much as i paid for the bike. they assure me the bike isn't dangerous to ride and as it was always going to be used as a winter bike, I'm going to leave it as it is until the summer and then change the frame.
   As for the side stand being on the right hand side, that's a mod that's been done by the previous owner, so the oil doesn't drain into the rocker case when standing, and cause smoking on start up. He told me that BMW re comended it. should i trust him?

[CRASH]

As for the side stand being on the right hand side, that's a mod that's been done by the previous owner, so the oil doesn't drain into the rocker case when standing, and cause smoking on start up. He told me that BMW re comended it. should i trust him?

No, BMW would never recommend that.

[Opus]

As for the side stand being on the right hand side, that's a mod that's been done by the previous owner, so the oil doesn't drain into the rocker case when standing, and cause smoking on start up. He told me that BMW re comended it. should i trust him?

No, BMW would never recommend that.

I thought that looked out of place............. :dunno2:

[CRASH]

Curious, where is the frame bent?  Is it the sub frame that the seat and tail piece sits on?  It does look like it may be a little tweaked, not sure you need to buy a new frame if that is all that it is.

[ovanman]

It's the rear sub frame at least, the frame straightener thinks the front maybe bent as well, but he can't be 100% sure until he gets it on a jig. however, the cost of straightening the frame is dis proportionate to the cost of the bike, but a second hand frame, with guarantees and paper work is relatively cheap, and I'll be able to do the work myself.

[CRASH]

How much to get it checked?  How much work to get it to the point of getting checked. If it tracks straight (and with the yahoo that was working on it before, who knows - but if it pulls at all in either direction, take one shim out of the rear wheel mount and try that to) it could just be a sub frame, they are pretty noodly on most bikes. remove all the plastic, get an 8 foot piece of pipe, wrap rags around where it will contact, have a few friends hang on to the bike and bend it back.  I have straightened many a sub frame this way (did an RT a few months back for a friend the same way).  A little tweak up top is going to move that rear fender a lot.

And I will be honest  :euro , BMW does NOT recommend this ... because they want to sell you parts. :D

[Tio Jaimito]

I have also seen posts on bent swing arm/axel housing.  Where the square swing arm was not squared up to the frame.    It may be a little of both.  This is why we don't do acrobatics on the old girls.

uj