Hello I have acquired a 1989 K100RS ABS with 64000 miles. This is my first BMW and I love it. I just finished my first 1000 miles on it and all seems well! I had the brakes professionally serviced and have a few winter projects in mind for this great bike. I plan to keep it as close to stock as possible but would like to change the seat\lower the seat hight a bit (I am 5'8 160lbs so the bike is a little tall for me as is) and replace the 26 year old rubber in the intake manifold (sucks a little air). So far my only issue is a noticeable fork flex back and forth in the direction of travel (as seen through the faring while riding) at 70-80 MPH. I will search the forums for these issues and look forward to learning as much as I can... Oh yea, and riding...

Welcome to the forum too.....

Same height at 5' 8" and weight......tried the 92LT and the 84RT, a few differences...

1 You can pull the fork stanchions up about 10-15mm.
2 Rear tyre stock is 130/90 but you can also go 140/80 which gets the rear down 5mm.
3 Get some height in your boots, again 10-15mm is easily done.
4 The seat may be an issue, the Comfort seat is the higher one but it is definitely more comfortable. The standard one is lower due to less padding.
5 You can get a shorter rear shock.
6 There is a low seat conversion kit which includes a different seat and some other essential components. But its not as comfortable so should be a last resort.

Welcome to the forum from the Great White North!  Nice to have another '89 K100RS Special Edition here as well.  The white bags make it even more rare.  I too and trying to keep my bike as stock as possible.  Allows me to get "collector" plates for about $200/year and most parts are easy to track down on the net.

As this is a K100 site, though, in your avatar picture you may want your K to be in front of that purple thing  

Darrin

HiYa Slim welcome to the forum. If you are getting fork flex like you describe you have a major safety problem. I most certainly would not ride it as it is. Firstly check how much you can move the forks back and forth while the bike is on the centre stand. I think that the flex is an optical illusion as the fork legs move up and down but because you have a restricted view through a small aperture they appear to flex.
Good forks shouls move at the absolute outside less than 1mm with the bike on the centre stand and that would take quite a bit of force for that movement.

Thanks for the list to check Olaf! I will go through... I might just need bigger boots! 

I can't seem to find any other white bags anywhere, nvboy so I will need to rehab these a bit... I will take a pic of just the K...(for the record, the sporty is maroon  )

I think you are correct Rick. I get no play in the forks while on the center stand and the front wheel spins as it should... I will play with air pressure and see if I get a better result. Reading through posts I see others having better luck with more air pressure, I am running at spec pressure from a Clymer manual (32.5F-36R).

I have found as have many others here that the more modern tyres do perform best at higher pressures.
We must remember that the Ks are 20-30 years old but certainly perform as well if not better than many modern bikes so when we apply the modern thinking to then we have bikes that are in almost evert aspect as good if not better than the bikes of the last few years.