new chainset for my trek 1.2 compact

If you already have a compact, I can't see a triple giving much extra flexibility. With 10 speed gearing it is entirely possible to go with a wider range cassette (like a 28-12 or 30-12 ish) to achieve the same thing as and when you need to.

Upgrading to a triple would be expensive. Not only would you have the cost of the crankset but you would need a new left triple compatible shift lever, a new triple compatible bottom bracket, a new triple compatible front derailleur, and possibly a new triple compatible rear derailleur. Oh, and a new chain. It is a lot of work and expense for something that you don't really NEED. You would be better staying with your compact crankset and getting a new cassette with a lower gear like tafi suggested. Just be sure that you don't get a cassette with a low gear that is larger than what your rear derailleur will handle.

hmmm thanks guys! well either way i need a new crankset, and so i bought a tigra double@

parker-international.co.ukShimano Tiagra 4500 9 Hollowtech II Double Chainset.htmlOpen ↗

along with the bb

I don't need to change anything else would i? cause i wasn't sure about compact and double, from what i've read it jsut seemed like a compact had smaller chain rings which made hills easier.

I'll probably change the casset later when it wears down then!

you had a compact, now you have a std double, depending on how strong of a rider you are, you will probably be fine. the compact double gives roughly the same range of gears as a triple would because you usually mate a compact double to a larger casette like an 11/28 or 11/32 while many people who ride a std double do so with an 11/25 casette in the back which really doesn't provide a very low gear for hill climbing. I'm 6'3" 240 so a compact double or a triple is pretty much std equipment for me.