The shift lever on my 1000S project bike was wobbly due to wear on the pivot stud and inside the shift lever bore. A quick check showed about .015” clearance when it should have been about .003”.
The frame stud is 12mm (.472”) and welded to the frame. After consulting with a machinist friend we decided the best fix would be to replace the pivot stud with a shoulder bolt (.500”) and ream the shift lever oversize to match. We could have bushed the shift lever back to 12mm but ? inch was much easier in terms of finding the bolt and reamer.
A drill guide was fabricated to assure the hole was drilled straight using a block of aluminum and a slip-in hardened guide.
- Frame stud shortened
- Guide placed over stud
- Drill the hole – two steps, starting with small drill bit first
- Remainder of stud ground off
- Hole tapped
- Ream shift lever oversize (not shown)
- Install new bolt, after zinc plating
Turned out well; shift lever now is nice and solid feeling.
The frame stud is 12mm (.472”) and welded to the frame. After consulting with a machinist friend we decided the best fix would be to replace the pivot stud with a shoulder bolt (.500”) and ream the shift lever oversize to match. We could have bushed the shift lever back to 12mm but ? inch was much easier in terms of finding the bolt and reamer.
A drill guide was fabricated to assure the hole was drilled straight using a block of aluminum and a slip-in hardened guide.
- Frame stud shortened
- Guide placed over stud
- Drill the hole – two steps, starting with small drill bit first
- Remainder of stud ground off
- Hole tapped
- Ream shift lever oversize (not shown)
- Install new bolt, after zinc plating
Turned out well; shift lever now is nice and solid feeling.
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