[dombey19]

My LBS wants to replace the Tiagra front derailleur on my son's bicycle with a 105 front derailleur. At first I thought fine, it will shift better (maybe). Now I am wondering. The Tiagra is a 9 speed derailleur; the 105 is (I think) a 10 speed. Maybe this doesn't make any difference since it's a front derailleur only. It's a triple chain ring. Will this be a problem at all?

 

[davcruz]

It will not be a problem, but why do they want to replace it and why do they not want to put a Tiagra back on it? FWIW, a 105 FD is cheap, but it probably won't shift any different than a Tiagra IMHO.

 

[Mr. Versatile]

In the Shimano component line the 105 is a step up from Tiagara.

 

[zender]

It will work fine. maybe 105 is all they have in stock?

 

[lawrence]

Difference between 105 & Tiagra is maybe a better quality finish? IMO, I don't think you'll notice any better shifting and I agree, maybe that's all what he has in stock but I can't imagine there's not much difference in price, $5? $10?, minimal, even a Ultegra front derailleur isn't much.