Summary

This is a thumb-shift assembly for a Strumey Archer 8 speed internal gear hub.

Instructions

This item has not been tested in the real world. I created this design because I was exploring the possibility of making this and I wanted to print a prototype. However, I was able to instead purchase a 5 Speed hub which has a thumb shifter available from the manufacturer. The cable pull distance is based on information available on the internet, not on testing I have done, therefore the shifter is not guaranteed to work, but it might be close.

This design was created for use with a 3mm ball bearing, and spring washer to provide pressure to the ball bearing and provide a satisfying 'click' when moving between index stops. A screw is required to hold the retainer cap to the base. The base is non-threaded in the model but could be tapped by using the appropriate screw. The dimensions of the base and retaining screw were based on a Suntour down tube shift lever, so standard parts may fit.

The index ring was designed so that it could be easily replaced. Of all the parts, it will receive the most wear, therefore it was also made so that it could be easily machined from a more durable material. Additionally, it could be adapted to a different derailleur or modified to make adjustments to the design without re-printing the entire project.

TODO: Create a printable spring washer which provides tension to the ball bearing for demonstration purposes. Create a snap-in retaining screw. Make bearing ring and retaining cap more compact. Make shift lever more classy. Make the retainer cap more classy.

Index Shift Lever for Strumey-Archer 8 Speed Internal Gear Hub