Originally posted by davek
What about the difference between Sora and 105?
This thread is timely for me because I'm looking at a new touring bike and my choice is between one that comes with Sora as standard and one that comes with 105 as standard but costs a lot more...
Since it's for touring I'm not bothered about performance/responsiveness so much as reliability over long distances. My current bike has friction shifters mounted on the downtube so in any event it will be a totally new experience for me.
Well, Sora is essentially the bottom of the lot as far as true road groups go -- it's really about as low as you can go without crossing over into the realm of low-end general purpose MTB/hybrid systems, as you might find on a department store bike.
Unfortunately, it's generally problematic and not particularly durable at the same time. I know bike shop guys that are only half joking when they complain that Sora components sometimes require a little
bending to get them to work cleanly. Even if you're planning on doing touring mostly, and don't expect to demand race-responsive shifting from your drivetrain, there are better choices. In my opinion, Sora's worth considering if you ride once or twice a month, or
absolutely can't afford anything better.
Aside from being heavy, clunky, and altogether unrefined, it's also of a different basic technology than the entire remainder of the Shimano road group tree. From Tiagra through Dura Ace, the remaining 9-speed systems share a core design and an interchangeability of parts. Some of it is subtle and invisible -- some of it isn't. The shifter design is most conspicuous. Sora shifters lack the integrated brake-lever/paddle that the rest sport; instead, you've got thumb paddles that are pretty imprecise and difficult/impossible to operate from the drops.
If you're intent on saving over 105, I'd certainly recommend a hard look at Tiagra or a comprable Campy group -- though I still view 105 as a tremendous value.
Good luck deciding!