We have a major update to our page on upgrading older bicycles to index shifting. This can be done at a lower cost than you may expect, because there is usually no need to replace the rear wheel! Shifter choices, parts compatibility issues.
![Shimano RapidFire shifter](http://cdn-0.sheldonbrown.com/blog/wp-content/uploads/2017/09/dual-lever20170822_112630-600x360.jpg)
Shimano RapidFire shifter