garrettpen

I have a roughly 2004 Specialized Seqouia with a 9 speed rear Tiagra derailer. When I purchased the bike the derailer was missing a bolt and a Idler wheel, I purchased a replacement off ebay bolted it on and the tensioner pulley is rubbing on the biggest gear. Even with the screw turned in all the way so I bought a longer screw but I still have the same problem. Thinking maybe it was the derailer itself I swapped the pulleys onto the original derailer and bolted it on but I still have the same issue. Any suggestions? Thanks in advance.

FastJake

What size cassette are you trying to run? Have you checked your chain length?

AnkleWork

Which pulley was missing -- upper or lower?
Which pulley is touching?
Which cassette do you have?
What cage length?
Is the chain length correct?

FBinNY 

OK, before going further, I want to confirm that I'm reading his right.

1- the upper pulley is touching a cassette sprocket -- hopefully the original and not a larger replacement.
2- you've tried adjusting the B-screw in the back of the upper body, to no avail, even with a longer screw you added.

Assuming that's the gist, start by removing the rear wheel and looking at the back of the hanger and seeing if the screw is touching the stop tab on the hanger, or is trapped next to it, or if the angle it's at is causing to slide under and beyond the stop.

Let's confirm my assumptions and check that the B-screw is engaging the hanger stop before going further.

garrettpen

Not sure on the chain length or cassette as far as I know everything is stock. Here is a pic to clarify.

FBinNY 

See post 4, I suspect that your B-screw isn't touching.

garrettpen

I'll check when I get home it makes since especially with the longer screw that if I turned it in too far it could come off the frame but if that is the case and when I have the screw turned in as far as I can while still on the frame and the plastic gear is still touching the cassette then what?

FBinNY 

There are fixes for that, but let's take it one step at a time. From the photo, the RD is higher than I'd have it for a wide cassette, and you should be able to get it lower, so I'm suspecting that the screw isn't touching the cam. I'd like to see a photo from the back, because if that's the problem, I'd need to see the exact situation to suggest a remedy.

RoadGuy

I took a quick look at Bikepedia to look up the specs for your bike since I am not familiar with that model. Your bike would have come with a 12-25 cassette from the factory. Looking at the photo you provided, I can see that the cassette that is on there current has a much larger large cog. I suspect that the problems you are having with the bike are all due to the improper way that the cassette was replaced.

The missing pulley was properly removed by the previous owner when he/she notice the pulley hitting the cassette cog after replacing the cassette with the different one that he/she did.

If the chain was not replaced with a longer chain at that time, the chain could be too short, can could have caused the derailleur hanger to bend. Being too short can also cause other problems like shifting problems.

I would suggest either taking the bike to a LBS and getting the problems sorted out since there are more than one, probably that started with the installation of the cassette with larger cogs. If you want to try to iron the problem out yourself, maybe the place to start would be with the replacement of the cassette with an original size 12-25 cassette to see if the bike will run properly and that can give you an idea of whether the chain length was part of the problem. The rear derailleurs that you have (original and the replacement) may not be compatible with the cassette that is currently on the bike, and the existing chain may be too short to run with the currently installed cassette.

When the size of the cassette is changed, it is often necessary to change the chain (length), and the rear deralleur (capacity due to cage size). You cannot change one part, and expect everything to wlrk the same because the parts were spec'cd to work as a system, and changing one part affects how other parts work.

garrettpen

Nailed it Road guy! It has an 11-32 cassette on it, I'll get it swapped out for a 12-25 and see what happens. Thanks!

garrettpen

So apparently the previous owner also decided to put a 9 speed derailer on it (it has 8 speed shifters) I can't find an 8 speed derailer anywhere is there something else that would be compatible?

BikingGrad80

I have a 9 speed ultegra RD-6500 running an old 7 speed drive train with dt shifters and it works beautifully on my beater. 9 Speed RD's should be fine on an 8 speed drive train.

SkyDog75

8-speed and 9-speed Shimano derailleurs use the same cable pull ratio and are therefore interchangeable.