Originally Posted by
steelbikeguy
So what the heck was Bridgestone doing with "click shifting" back in '79?
Maybe it was just a noisy version of friction shifting?
.. and do I need to ask Grant P. to see if he remembers?
Steve in Peoria
(happy to have an excuse to dig out The Dancing Chain and browse through it)
As above, there were lots of attempts at index shifting, some dating back to the turn of the century. Shimano’s SIS combined several enhancements that made it successful:
- The Uniglide sprockets and chain that sped up shifts and helped prevent hanging on tops of cogs.
- The “Centeron” upper derailleur pulley that allowed slight misalignment between derailleur and sprocket.
- Special cables and cable housing that for more consistent coordination between the shift lever and derailleur.
- Shimano’s tighter specs for dropout and derailleur hanger alignment.
It wasn’t one big thing… just a bunch of little things that Shimano insisted on that created their steamroller in the ‘80’s.