12. Frame: examination and renovation

  1. The frame is unlikely to require attention unless accident damage has occurred. In some cases, renewal of the frame is the only satisfactory remedy if the frame is badly out of alignment. Only a few frame specialists have the jigs and mandrels necessary for resetting the frame to the required standard of accuracy, and even then there is no easy means of assessing to what extent the frame may have been over-stressed. Note that BMW specifically advise against straightening or repairing components such as frames, fork stanchions and wheels because of the real danger of a fatigue fracture appearing subsequently.
  2. After the machine has covered a considerable mileage, it is advisable to examine the frame closely for signs of cracking or splitting at the welded joints. Rust corrosion can also cause weakness at these joints. Minor damage can be repaired by welding or brazing, depending on the extent and nature of the damage.
  3. Remember that a frame which is out of alignment will cause handling problems and may even promote 'speed wobbles'. If misalignment is suspected, as a result of an accident, it will be necessary to strip the machine completely sa that the frame can be checked, and if necessary, renewed.
  4. BMW specifically advise against fitting a sidecar or a trailer to any of the machines described in this Manual. Note that they also advise against fitting RS- or AT-type fairings to K100 models (with rigid engine front mountings) because of the risk of vibration damage. Check with an authorised BMW dealer for details.

Next Section: 13: Footrest: general