You are reading a single comment by @Stu_F and its replies.
Click here to read the full conversation.
London Fixed Gear and Single-Speed is a community of predominantly fixed gear and single-speed cyclists in and around London, UK.
This site is supported almost exclusively by donations. Please consider donating a small amount regularly.
@Stu_F
They are Shimano SIS (shift index system). There seems to be a number of models, none of which specify which ones they are on the side so can't be more specific than that, sorry