do i have to replace front derailler?
 

i have a shimano 105 triple front derailler for a 52-42-30 crankset, i wish to switch to a double crank since i dont use the 30. is there a way to use the attached triple front derailler? are there any instructions online that i could follow so that i wont have to replace the derailler too to a double?

because from my basic understanding, if i downshifted on the 105 triple shifter, it might just drop to the crankcase in the absence of the 30 gear.

thanks.

Yes, this can be done. Shift down to the smallest chainring, flip the small shifter a few extra times to make sure that all of the cable is out of the shifter.
Release the cable from the derailleur. With the double crankset on the bike adjust the front derailleur following all of the instructions found at http://www.parktool.com. Do all of the steps in proper sequence leaving nothing out.
The triple derailleur should work OK with the double crankset but not as well as a double derailleur. It is always best to use derailleurs and cranksets designed for each other but there is quite a bit of tolerance for mismatched components. The triple derailleur is wider than the double.

Al

what about the shifter, it's triple too
 

i just saw the prices of front derailler and they worth considering since its not that expensive but what about the shifter? it's triple too shimano 105. can a double derailler and double crank work with the triple shifter?

With the new double setup, the third shifter position (the highest) will disappear...or actually be locked out by the derailleur's high limit screw. The second position (which formerly was for the middle ring) will be your new high position.

Works fine.

Just be mindful of your shifting. You can still push the lever and damage the STI if you push it against the F.D stops enough. There's a warning pamplet attached to the shifters new that specifically warns you of this.

Yes, the triple shifter can work with the double crankset. However there have been issues with the 10-speed 105 triple front shifter when used with a double crankset. In the past all 105 STI shifters were considered double/triple compatible. But recently Shimano has been issuing a 105 double shifter.
All 9-speed Shimano shifters except Dura-Ace were double/triple compatible.
The problem with the 10-speed triple shifter on a double setup has been due to overshifting to the big ring and locking up the shifter. I have not personally seen this.

That's the warning pamphlet.

You'd have to be a mega ****** to do this. That being said I can easily see a newb doing this by accident.

Are you loth to replace the derailleur because you don't have the money, or because you're not sure that you can set it up properly?

If it's the setup, see the links in this thread.

If it's because of the money, please be aware that replacing the crankset is a silly use of money in the first place. If you don't use the 30, then don't use the 30. Put your money in the bank.

I agree. And if the issue is that you don't want to accidently shift onto the small chainring, I assume that you could set up the derailleur and shifter as if it were a double, just like you'd have to if you changed the crank. Frankly, I'd leave it as it is. I "never" use my granny ring on my triple. That is until I was in the middle of a ride I'd never done before and hit 4 very steep hills in succession that inspired me to use it. I might not have made it home without granny's help. I even passed a couple of much stronger riders struggling up the hills with their lowest gear on their doubles.

Cranksets ARE pretty expensive. Front derailleurs are cheap. If I was going to replace the crankset, I'd probably just shell out for the new derailleur too. IMO, you could save $ by buying a lower level front derailleur - there's not a whole lot to distinguish a Sora from a Dura Ace, except weight.

You and I were posting at the same time. I had not seen your post when I typed mine.

Jinx ?

No, great minds think alike.