1 - DISCLAIMER and SAFETY WARNING
Doing any work or making any adjustments with the steering, suspension, or brakes of a motorcycle is dangerous. Something as simple as leaving a single wire cable unsecured can cause it to become caught resulting in loss of steering. Even if you do all the things described in this article exactly as described and follow all these instructions to the letter, the processes described in this article can still be very dangerous. Bending of parts can lead to metal fatigue and possible structural failure which can cause expensive damage to parts . Improperly adjusted assemblies, poorly torqued hardware, over-stressed parts, or any number of other factors can result in poor operation, loss of control of the motorcycle and possibly even an accident which can result in personal injury or death. In this document I am merely reporting what I learned as I went through this process on my 1979 R100RT. There may or may not be major differences between my bike and yours which could make some of the procedures outlined here dangerous for you to perform as described herein. There are also procedures mentioned but not fully described, such as replacement of fork seals, adjustment of steering bearings, and more. If you are not familiar with the proper procedures for any of the adjustments or processes contained in this article then you should not attempt them. If you decide to work on a motorcycle yourself, after the work is done you should have the motorcycle checked by a trained and certified motorcycle mechanic to be sure that it is in safe operating condition before it is ridden. By continuing to read this information you agree that the author is free from any liability whatsoever. If you do not take 100% responsibility for the results of reading and possibly applying what you read here, you may not read further. Reading this article and/or making use of any of the procedures in this article signifies your release of the author from liability.
What the Fork is Going On Here?
I am not suggesting that you should attempt the procedures outlined herein, but if you choose to, before beginning, make sure that you read this article from start to finish and be sure that you understand all of it. I suggest printing out every page and having them on hand. Be sure that you have all tools on hand before beginning and that the bike can be left for an extended period of time where it is sitting once the process has begun. You should also have (or be able to create) about five or six feet of clearance on each side of the bike. It might take quite a few days or even a week or two to do all of this, so plan ahead! Do not begin until you understand the procedure. Get help ahead of time if you need it.
There are a number of procedures not outlined here such as how to change the fork fluid and how to adjust the brakes and the steering head bearings. You should be familiar with these related tasks and others similar to these before proceeding with the series of adjustments outlined here. Also check your shop manual for proper torque specifications, fluid volumes and specific procedures for your bike that may vary from those discussed here.
Also be aware that this article and the procedures contained herein apply to the '79 model year of the BMW R100RT unless specifically stated otherwise, and may or may not directly apply to your model. There are some major differences between this bike and the earlier models as well as procedures that differ. If you have a /5 or /6 I suggest that you take a look at Duane Ausherman's website for more specific information on these models. Even so, the basics of fork tube alignment on airheads with telescopic forks are contained herein, and the owners of virtually all /5, /6, and /7 bikes will find lots of useful information.