Originally Posted by
rhenning
I wouldn't spend the money to up grade what you have. As you wear things out just replace them with Ultegra parts. If you want to get faster work on yourself more than the bike. Roger
+1 to everything he said. The weight savings from upgrading to Ultegra or even Dura Ace will have minimal to no effect on your "speed" and will only serve to lighten your wallet. Upgrade components only as things wear out and work at upgrading you. That will pay far more dividends.
Your current high gear is 127 gear-inches and will produce 38 mph at 100 rpm if you are strong enough. That's the sort of gear very good professional level sprinters use so you are in no way limited by your current gearing.