Front derailluer Question

[Joshman_75]

Ok, I'm a little confused and need some clarity please. I have a TREK road bike that I use for Triathlons. My front derailleur broke and will not shift. I want to replace it, but all I can not seem to find one for a 21 speed. Why? What am I missing? Am I looking for the wrong thing? What should I look for? Are all front derailleurs the same? universal? Help Please. Thanks

[cny-man]

Derailleurs are designed for the number of chainrings, not total speeds. You need a triple front derailleur. Google "install front derailleur" to learn what you need to know. sheldonbrown.com and parktool.com offer the best advice.

[Joe_W]

It also should say "7 speed" (though 8spd will be fine, too). At some point in time people stopped talking about the total # of speeds and started to talk about the cassette (rear) only... Check that the dérailleur is specced for the size of the small and large chain ring (# of teeth)

[Joshman_75]

Thanks guys, I appreciate it. You were a lot of help and I am now more educated today than I was yesterday. Off to shop for a new derailleur. Thanks again.