Trek 1.1 gear problem

[DeanN]

I have a problem with two things. One is when the chain is on the front lower sprocket I have a hard time getting it back up to the top sprocket. I have to try several times.
And number two, when the chain is on the top front sprocket, unless I am in the 3 highs gears, it rubs the derailer on every half turn. This bike is only about 3 weeks old and I have taken to the bike shop 3x to have them fix it. The last time I was there they said that the chain rubbing on the derailer was normal. That does not sound right to me.
Does anybody have any ideas about what to do? Should I go back to the bike shop and talk to the owner? Should I call trek and see what they might have to say? Is it normal for this bike to do that? Should I buy a new/better gear system to put on the bike?
Thanks.

 

[tafi]

You shouldn't have to buy a new gear system after 3 weeks of use. and neither should you see rubbing in that many gears. However you can expect rubbing in "cross gears" where the chain must run from the large chainring to large sprockets or from small chainring to small sprockets.

When in the big chainring, you should limit yourself to the smaller two thirds of the cassette sprockets, and when in the small chainring, to the larger two thirds of the cassette sprockets.

Some of the behaviour you describe (the inability to shift into the large chainring) can be attributed to cable stretch which always happens in the frst month or two of ownership. However, your mechanic should be able to adjust for this quite easily.

Your mechanic should also be able to tell if the deraillur is set at the correct heght from the teeth of the large chainring (1~1.5mm is optimal) and aligned parallel to the chainrings. These will also affect how good your shifting is.

I wouldn't accept the current situation if I were you, but I doubt you would get a great ammount of joy out of going back to the same place again (seeing as you've already been three times).

I'd advise the DIY approach, which will reqire some reading.