Need Help: B SCEW - Guide Pulley Alignment Problem

Is the derailer properly attached to the hanger and the hanger straight? Is it matched to the cassette or is it a brumby? Just my 2c

Ariel said:

Hello,
I'm looking for some helpful advice.. I am trying to adjust the upper/guide pulley away from the cogs. I know that the B Screw is supposed to accomplish this but my B Screw is tightened all the way down and the pulley is still too close. Is the problem in the Spring? Do I need to move the spring to a different spring hole in the plate? Or what else could be the problem? I'm kind of stuck. Thanks in advance! 🙂
-Ariel

There's a lot of vital data that you've left out. What kind of derailleur? How many teeth on the largest rear cog?

chamelion said:

Is the derailer properly attached to the hanger and the hanger straight? Is it matched to the cassette or is it a brumby? Just my 2c

thanks for the reply. the deraileur is attached to the hanger and the hanger looks straight. not sure what 'brumby' means. but these are all original parts that came with the bike. i know there is supposed to be about 6mm clearance from the guide pulley to the largest sprocket. and i definitely don't have that. it is really close.

thanks, Ariel

Retro Grouch said:

There's a lot of vital data that you've left out. What kind of derailleur? How many teeth on the largest rear cog?

thanks for the reply. the bike i'm working on is a 2005/2006? Trek 1000 triple chainring bike. this is Shimano Tiagra derailleur. the largest cog has 26 teeth.

thanks, Ariel 🙂

Have you double checked that your chain length is correct? My first thought is that it might be sized incorrectly. see:
parktool.comreadhowto.aspOpen ↗

serenaslu said:

Have you double checked that your chain length is correct? My first thought is that it might be sized incorrectly. see:
parktool.comreadhowto.aspOpen ↗

thanks for the reply. the chain looks like a good length. but today after calling Shimano, they suggested shortening the chain. so i took 2 links out of the chain, but it doesn't seem to make any difference. also i can't even really tell that that b-screw really makes the pulley move at all in any direction really. i'm still stumped. 😕

Well what started this was when I was reading a repair manual that said I needed 6mm of clearance between the guide pulley and the largest cog. I only had about 2-3mm. But after talking to my LBS tonight, they said that they usually set the guide pulley as close to the cogs as possible without it touching. So I guess I'm ok after all! Thanks for all your suggestions. I got the bike working well and I got to give it back to it's happy owner tonight. Now maybe I'll have some free time to get my own bike tuned-up. 🙂

Happy riding,
Ariel