Originally Posted by hobiek

if you really want to upgrade go with the wheels. a lighter set of wheels will make a noticeable difference. for every 454 grams or 1 pound you take off your wheels it's like losing roughly 7 pounds on the rider, which should ultimately increase your performance. plus you'll have less rotational mass, which will result in faster acceleration and and faster starts from a dead stop. you'll notice going up hills will be a little easier and you'll might even increase your average speed as well.

you can go to any LBS and they'll tell you the wheels are one of, if not the the biggest difference you make on your bike. i'm assuming the wheels on your bike are fairly heavy to start off, so a good light set of wheels will be a huge difference.

I went from Alex R500 wheel set on my Felt Z85 an Easton wheel set (saving 1.70 lbs) and the bike feels totally different, in a good way. As noted before my acceleration has gotten better, average speed has gone up, my top end speed has gone up, i able to maintain a high speed in a lower gear to a longer period of time, going up hills has gotten easier as well.