Originally Posted by
fietsbob
This is where bypassing a bike shop fails you.. they will sell you the right chain and dissolve
your ignorance of common terminology, and for a modest cost even put it on for you.
but the basics, math, 21 is what? 7x3, right? do you count 7 cogs
stacked up on the back wheel..?
your first hint...
Wrong. Youtube how to size a chain by mock fitting it, then buy a cheap chain breaker and a universal chain. No math needed, no LBS upselling, you get the chance to learn a fundamental skill, and you can show up the forum know-it-all who thinks that using the word 'terminology' against someone is a put-down.