Originally Posted by
AngryScientist
ultegra is higher up shimanos line-up than 105. they are both excellent performers.
swapping out sora to used 105 or ultegra 8-sp stuff is a bad move IMO. the sora stuff rides very well if adjusted properly, and you'll get used to planning your shifts. save your pennies until you can afford a new bike, or to take the whole group to current 10-speed.
This is the correct answer. I had a bike with 8spd Sora and I didn't like the shifters. I hemmed and hawed about how to upgrade them, maybe buying some old Ultegra, but at the end of the day I just bought a new bike with 10spd 105 and sold the old one. My new Allez is a thousand times stiffer because I didn't just upgrade the shifters, but also the bottom bracket, crankset and wheels. You'll be happier with a new bike than if you just upgraded your current. It's probably cheaper too. Upgrading my bike cost me $500 (after selling the old one). You couldn't upgrade your whole drivetrain to 105 for that.