BMW motorcycle telescopic fork bushings
|This page is about the BMW motorcycle models; R50/US, R60/US, R69US, R50/5, R60/5, R75/5.The BMW telescopic forks were introduced in 1968 on the /2 models and were designated by the suffix “US”. When the /5 models came out in 1970, they had the same forks. One of several problems with them was that of stiction caused by the bushings. These bushings are located at the bottom and just up inside of the fork tubes. They are held in by a snap ring. The old fixed bushings were replaced with “floating bushings” in 1972. This change solved the stiction problem from that source. Other sources, even larger ones, still existed.
All three pieces
The change is recommended for those forks that may still have the older, one piece, bushing. The aluminum center piece is trapped by the two outer threaded pieces, but still allowed to “move or float” around. You can see it in the middle photograph. The piston rod will not “stick” while moving up and down.
If your forks are not in nearly perfect alignment, then this change won’t help much. This is a small hole in the dam. I suggest that you plug up the larger ones first.
Go to the excellent article by Randy Glass on this issue.