Adding lower "hill climbing" gears to a older Specialized Allez.
I have an aluminum Specialized Allez that I bought used about 14-15 years ago. I'm not sure what year model it is. It has Shimano Tiagra components.
Also, it has a 59x39 crankset (two rings) and a 12x25 cassette (nine rings) . This makes it hard for me to go up long steep hills. I have a ride coming up that will involve a lot of mileage with lots of steep hill climbing.
How feasible would it be to change the gearing to make it easier to add hills. Maybe by adding a smaller third chainring? Would this be a good idea or bad idea?
Looking for suggestions for the easiest to implement, most cost-efficient solution. All suggestions are welcome. Thanks!
(Note: I am new to these forums and this is my first post. If this is in the wrong subforum, let me know and I'll move it.)