105 Shifter compatability - double to triple

[boy in a kilt]

Generally, the difference between a front mech for a double and a triple is in the cage length.

For your purposes, if the front derailleur worked on a triple, it'll work on a double.

Also, here is the Park web site. It'll tell you most of what you need to know.

[echidna]

Hi -
You will find that the 5500 shifter/brake levers are double/triple compatible - i.e. even though they were originally set up on a double they'll shift all three rings of the triple without breaking a sweat. IMPORTANT: This is not true of Ultegra or Dura-Ace shifters - you have to get a specific triple set to shift all three chainrings.
I say go for it, cable the beast up, and let 'er rip!

[SadieKate]

Generally, the difference between a front mech for a double and a triple is in the cage length.

For your purposes, if the front derailleur worked on a triple, it'll work on a double.

Also, here is the Park web site. It'll tell you most of what you need to know.

Front derailleurs for triples have taller back plates and wider spacing between the plates, and can have a different curve. Often the two plates are splayed also, a little wider at the back, to accomodate the chain line to the cogs. The splay is not as common as it used to be because front mechs have evolved over the years but there is a HUGE difference between double and triple derailleurs.

If you are using the triple derailleur that came with the bike and crankset, you should be fine. But if you need to replace it, note the above and be sure to get a 9-spd derailleur as 10 spd derailleurs are for narrower chains and chainrings.