Yet another shifting question

[southerngirl]

Hi,

My chain broke so I replaced it and I just got back from my LBS where they replaced my rear cog. I also replaced my shifter cables. That said, the LBS says my rear derailler is slightly bent and I may still have some shifting troubles. But, I rode today and it seems strange that while in my biggest and smallest ring in the front I have no problems shifting in the rear, but in my middle ring in front and putting pressure on the pedals up a hill, the chain is grinding in between gears. I also notice that I am getting scratches on my chainstay. Do you know if the LBS is right and I need to replace my rear derailler? or is there another problem? (I have already dropped so much money there, just want to make sure this will solve my problem.)Thanks for your help.

[No I'm Spartacus]

Firstly, why did the chain break? If your rear derailleur is bent, then yeh, it probably will shift/run a little nicer with a new one. BUT, as you have problems in only the middle ring, I'd be looking elsewhere first. When you say "grinding in between gears" is that in the rear cogs, or is it grinding up front? Did they use an 8 speed chain and cassette? (assuming the rest is all 8 speed parts).

[southerngirl]

It is a 9 speed chain on a 9 speed cog. It is grinding in the rear chain when the front cassette is in the middle. That is what bothers me, why just in the middle cassette? I am pretty sure the chain broke because of NO maintenance after a 100 mile mountain bike race including in the rain and rivers, and it sat for 2 months So, that is why I replaced the cables also. Also, I notice chain slap on top of the chain stay but close to the front cassette, which has never happened before. BTW, it is titanium so I thought that would never be a problem.

[What&son]

that might be one of the problems, if has excesive drag...