Replacing front derailleur

[Yellow Saddle]

It probably would be if my legs could do that!

Seriously for the commute it is about acceleration in traffic and sustaining a reasonable speed when possible - something around 15 - 18 mph

You changed your crank for all the wrong reasons.

 

[Dave the Smeghead]

You changed your crank for all the wrong reasons.

Well apart from the completely worn chainrings pehaps I did....

 

[Ajax Bay]

for the rides I do on the commuter I leave it on the large chainring and only use the rear gears

apart from the completely worn chainrings pehaps I did [change the crank for all the wrong reasons]

How can the middle and small chainrings be 'completely worn'?

Rather than jousting, @Dave the Smeghead please say what's wrong with the FD, so we can help. I suspect that the seat tube is oversized. Confirm your cassette is 7sp 14-28 please. Have you measured your chain recently?