Cycling Chain Ring replacement

If you're looking at replacing your chain rings all you need to know is your BCD (Bolt Circle Diameter).  It looks like your bike came stock with 50/34 rings which are compact and have 110BCD.  Which means you can buy anything with a 110BCD. If you want to check for yourself all information is stamped on the inside of both rings.

The crank length that Giant spec'd on your bike depends on the size. You can easily find your crank length stamped on the inside of your crank arm near the pedal threads. 

What are you looking to do with this? That could influence some of the information. And why the chainrings as opposed to the cassette?

As stated, the 50/34 is going to be a Compact because of the 110 BCD. You can just get 52/36 chainrings to replace. If this has been way too small you'll have to go bigger, to the 130 for larger rings.

The crank size will be stamped on the crank. Look for a number close to 170 or 175.

I'm thinking mainly down the road.  I'm slowly getting comfortable doing work on my own bike and was curious of the replacement of the crank arms.  Also interested in looking at a 52/36 chainring down the road for the option on flatter courses, and overtime be able to use the 52/36 when I get stronger.

Swapping chainrings is one of the more simple tasks, though it depends on which chainring bolts you have as to what tools you need.

SRAM currently uses a set-up that takes a 5mm allen key on the outside bolt, and a 6mm allen key on the T-nut. Older SRAM takes a Torx wrench (a pain).

Shimano and most others take a 5mm allen key on the bolt, and a special chainring nut wrench (http://www.parktool.com/product/chainring-nut-wrench-cnw-2).

Right now I'm rocking a 50/34 with a 11-28 in the back.  I also have a 12-25 for my trainer wheel.  What would be the benefits of jumping up to a 52/36 or 50/36 like you suggested with my current cassette options? 

Second question: If I did go with a 52/36 and stayed with a 11-28 or 12-25 would it be that much harder to climb?  Would I really notice the difference?  Or.... would staying with my current set up but getting like a 11-23 allow for a similar ride as a 52/36 with a 11-28?

Thanks for all the help guys.

I'm finished with tris at the moment so no need to worry about the run   But great thoughts on the 12 and 11 comparison.  I live in Northern VA near DC so there aren't a ton of hills but my usually range from short steep .2-.6 of a mile climbs around 6-9% and then longer 1.2-1.8 mile 3-5% climbs.  I haven't really attempted the mountains out near West Va quite yet.

There isn't really a need to move up in the size unless you're running out of gears a lot. Not so much on the steep downhills, but on sections you hold for some time.

34 to 36 would be noticeable, but not necessarily that much harder. How are you doing now? Do you have to push it in the bottom gear often? If you can make the climbs at a cadence you're ok with a gear or two off the bottom, you're likely ok to get a tighter cassette.

And jan is right about the spacing on the 11-28. The bottom half has a lot of gaps in it. If you're likely to need that range for awhile and want to do something about it, something like a 12-27 or 12-28 should help some.

That's a rather personal question...

(cue Python Lifeboat sketch)