BMW motorcycle throttle control casting (perch) wedge |
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The perch wedge is the common name of an important part of the clutch and throttle controls. It was used on all BMW motorcycles from 1956 till at least the /7 and maybe longer. It's function is to keep the clutch and throttle castings from twisting on the handle bars. It is inconvenient to turn the throttle and have the whole throttle casting turn. The part is still available and costs $12 in 2004. I do know that Vech has it. That seems expensive, but it always was costly. If you suffer the consequence of failing to have it, that price will seem very cheap indeed. Install one in each side. Don't waste your time trying to find an alternative for the original part. The perch wedge is almost invisible when in place. One end of it can be seen if one looks from the center of the bike outwards and under the casting. In the gap, where the two parts of the casting almost come together to tighten, is a small triangular space. In that space is the wedge. It is common for grease and dirt to cover it up. I then use a thin wire to stick in the greasy hole. If the wire goes in, then it has no wedge. Many owners aren't even aware of its existence. The owner typically removes the throttle or clutch casting and the wedge falls onto the floor. IF it is found later, the owner has no clue what it is or where it came from. Check your bike to see if you have them. If you don't have them installed and the controls are tight, then you may have 7/8" handlebars. That is really bad and often breaks the castings.
If you look closely, you can even see the teeth of the wedge.
The wedge seated in place in a casting. The screw that tightens the casting squeezes the two parts together and forces the wedge into the chrome of the handle bar. The slightly curved part, that is against the bar, is made up of several lines, or serrations, that "bite" into the bar. This keeps the control casting from rotating on the handle bar.
This is the top view showing the groove that the tightening screw "fits into." This keeps the wedge from moving sideways.
This view shows the serrated edges, or teeth that "bite" into the bar.
This shows the end view of a BMW motorcycle perch wedge. More information on controls and cables
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This page was last edited:
04/02/2006 - copyright
Duane Ausherman |
