In a lot of situations 10 speed, 12 speed, 18 speed, 21 speed, and so on are just marketoid fantasies. On many old 10 speed bikes, 8 different gear combinations were all that was practical.

The rule of thumb was DON'T USE BIG-BIG, SMALL-SMALL sprocket combinations.

Modern bushingless chains have a lot of lateral flexibility, also, they are generally narrower. Short chainstays compound problems.

verktyg

Chas.