My son told me that that is pretty standard with the gearing on nearly all bikes in that price range (Mine is a trek 1000 too and so is hubbys) You have seen how my bike shifts at times. It isn't just the treks either - it is ALL the bikes with that gear set apparently. It peeves me too. Thankfully my son can make minor adjustments to it and fix it, but when he goes back to school in August, I will be hosed.

This is the specs on the gear set on the trek 1000: (Tiagra set)
Front Derailleur Shimano 2203
Rear Derailleur Shimano Tiagra
Crankset Bontrager Sport 52/42/30
Cassette SRAM 850 12-26, 8 speed

I don't need Dura-ace by any means, but I want something I don't have to monkey with! The 105 is the next step up in gearing, then Ultegra and then top of the line Dura-Ace. The 105 gear set can be had for about 900.00 on a trek 1200 or other brand bike, the Ultegra can be gotten on about a 2000.00 bike of any given brand. My next gear set will likely be a 105.

I am already eyeing my next bike....but to get a real difference in gears, It means spending a lot more money....

If you would like my kiddo to show you how you can adjust it some yourseslf so you don't always have to take it in to the shop, bring it by - he will be home after 8 this evening.