Changing from Tiagra to LX
 

Hi guys i have a touring bike which has a mix match of components which came with the bike since brand new what i have been thinking of doing is getting rid of the tiagra thriple crank only because the smallest cog i can put on is a 30 tooth the LX which i am told wont fit on to the tiagra has as low as 22 tooth which if i am right will make a huge difference would that be right?

Will i have to change the chain as well?
Will i have to change the front derailleur
and is it all worth the money its going to cost

You can put a 24t on the Tiagra crank. shimano makes racing triples because they can't make the front brifter shift from a 24 to a middle ring flawlessly. The shift can still be made, but it takes a little practice.

You could easily go to a 28 or 26 on the Tiagra. What size is the middle ring? The difference is sizes is where you could potentially have a problem. The chainrings can be replaced without even breaking the chain. Making the front derailleur work with a mountain type crankset could be a problem.

Al