SunTour shift lever bushings

These bushings lets an M4 nylon lock nut take the place of the two jam nuts used on the classic SunTour Bar Con shift lever.

The SunTour 3090 bar-end shift lever was once a ubiquitous piece of cycling equipment. Many still seek it out for use on modern bikes because they like its precision and convenience. A weakness in its design, however, means many examples of this shifter are no longer usable. The shifter depends on two jam-nuts to hold tension, and one of those nuts is deeply slotted. This slot makes it hard to adjust tension, and easy to over tighten and strip. The shifter is normally unusable when that slotted nut is lost. These nylon bushings, when combined with an M4 stop-nut, take the place of those unobtanium jam nuts. When using this combination, tension can be adjusted with a single screwdriver.

This print is two (2) bushings connected by a pair of 2mm sprues. You must separate the two bushings and smooth the residual sprues. When done, you will have bushings sufficient for two shift levers.

To use this bushing

• you must have the original screw
• you must provide your own M4 nylon lock nut

Installation steps:

1. Remove any remaining original nuts
2. Drop an M4 nylong lock nut into the bushing
3. Insert the combination into the recess of the shifter body
4. Insert the original screw
5. Adjust the tension by tightening the screw