Road Cycling - an upgrade worth doing?

Could use advice here. Have Trek 5200 with standard ultegra double crank set and on the back she's got a 12/25 cassette. I'm thinking of getting the FSA Pro Elite crank set, I think its only 515 grams (looks VERY nice) with the chain rings geared at 34/50. Figured it would offer good range of gearing especially for hills but wondered if the loss of a couple hundred grams at in that area of the bike would be noticable since it is roatating weight. Anyone ever change over to one of these FSA cranks?

Could use advice here. Have Trek 5200 with standard ultegra double crank set and on the back she's got a 12/25 cassette. I'm thinking of getting the FSA Pro Elite crank set, I think its only 515 grams (looks VERY nice) with the chain rings geared at 34/50. Figured it would offer good range of gearing especially for hills but wondered if the loss of a couple hundred grams at in that area of the bike would be noticable since it is roatating weight. Anyone ever change over to one of these FSA cranks?

The basic benefit to you will be the better ability to climb hills. Secondarily will be the weight factor. I don't know the weight differences between the Ultegra and FSA, but if it's about 200 grams as you say, that's .44lbs. However the weight loss will not be noticeable as a rotating weight loss, such as a lighter tire, but as an overall weight loss to the bike.

There is a certain cool factor with FSA cranks, and that in itself has intangible benefits to you. Personally I would discount the weight loss and figure the climbing ability is the overall reason to change cranks. And, if afterward, you needed even lower gears, you could change out your cassette for a 12/27.

I have the compact carbon cranks on a bike. They are really nice for spinning and hilly rides. My speed with them tops out at about 26 mph- a speed they don't frequently see. Hard to believe that she could feel the weight difference.
BTW they make an alum. version for less than $150.

the cranks are rotating weight too (you rotate the cranks (rotation) which move the chain (translation) which moves the cogs attached to the wheel which moves the wheel (rotation)). but the rotational inertia is much smaller because of the small radius (as compared to the wheels). basically, the more weight you take off further away from the axis of rotation, the more significant a difference you will feel.

don't think this is a moot point, because it's not. people have noticed a significant increase in performance after changing to a lighter pedal/shoe system. these and the crankset are a significant part of the rotating mass of the bike.

thanks for the advice guys.. its either the crank change or American Classic wheel set the lightest one they make. I only weigh 135 so I can use the lightest one they make.If I remember right there is a 400 gram difference between my stock wheel set and the American Classic Im looking at. That has to be awsome. I have been reconcidering the gearing on the cranks mentioned above and think I will spin out too fast. I like to go fast.

you can get those cranks, and mess around with the chainrings if you think you'll spin out too fast. they use a 110BCD, so finding chainrings to fit might be a little difficult, but i know TA makes a bunch of different sizes for 110. 34 is a bit small, but if you do a lot of hill climbs, it might be advantageous.

i'd reccommend going for the wheels if you're trying to save weight and looking for the biggest performance difference. you can upgrade the cranks later if you feel like it.