Lighter weight also means extra bucks and reduced longevity compared with what you have. Which means you'll end up paying out even more dollars in more frequent replacements, and more so if you're hard on your equipment.

Unless you're already down to 15% or less fat mass, I'm with the others on losing body weight first -- much cheaper (but maybe not easier) to drop three kilos off the bod, than try doing the same thing on the bike. Drop 5kg off your body weight, and you've probably exhausted the lightweight options to do the equivalent on the bike. Lighter wheels are a good starting point (given the longevity issues), but I believe they do more to improve acceleration than increase sustained speed. Acceleration still has an influence on average speed, of course, especially going uphill.

FWIW

R