[Dhananjay Adhikari asked about buying a Trek 1000.]
Dhananjay, I have a Trek 1000 (my commuter) and an older steel frame with a mix of 105 and Ultegra
components, and I've rode bikes with Tiagra. The Sora group on the 1000 is fine, but you may want to
spend the extra cash to get a bike with a Tiagra group (the next level up from Sora) if you can.
Shifting on Tiagra is noticably better. Shifting up on the front chainring especially is extremely
clunky with the Sora. The thumb shifters aren't a problem for me, but some people find them to be
cumbersome.
If you want to upgrade in the future, the 9-speed Tiagra is more upgradable than the 8-speed Sora.
With Sora, you can't do it piecemeal -- the 8-speed components are not at all compatible with the
9-speed world.
There's a world of difference in reliability between my (mostly) 105 bike and my Sora-equipped Trek.
I don't know how Tiagra would compare in this department.
These are engineering compromises to keep the cost low rather than real pitfalls. If the
shortcomings aren't that important to you then Sora will work just fine. Be sure to go for more than
a spin in the parking lot -- work the levers and get the feel for the bike. Keep in mind that if
something is just mildly annoying in your short test ride, that mild annoyance will be magnified
manyfold during a three-hour ride.
When I test rode my Trek 1000, for example, I noticed the front-chainring clunkiness but I thought
it'll just be a commuter, I won't be using the front derailer much, and I can compensate. (I have 3
rings, and the small ring helps on steep hills on my commute). I bike commute about 200
miles/month, and because of that stupid clunky front derailer I now wish I had gotten a Tiagra
equipped bike instead.
RFM