I’m adjusting the shifting on a trek 1000 sl with a shimano tiagra shifter and on the largest 2 cogs on the cassete the jockey wheel is actually touching the teeth of the cog. So I’m trying to adjust the b tension and I find it’s not doing anything at all. I was taking a closer look at it and realize there’s this channel in the derailleur for the tab of the b screw washer or whatever it is and if I have it screwed all the way in it doesn’t even contact the derailleur to adjust anything at all. Do I need a longer B-screw, is it something with a wrong derailleur hanger. I don’t understand, I’ve seen the same thing on another of my friends bike with a shimano derailleur also. The only thing I noticed it do at all, is slightly releive pressure off the teeth of the cassete cog but that’s only because the tab is rubbing on the wall of the channel but not the actual stop at the end of the channel like where it should be I assume.
by Vivid_Bag4462
3 Comments
How big is the cassette? Could be too big for the derailleur.
B screw only does so much.
Max cog on an RD-4400 was 27t when it was brand new. Fully maxing out the B-screw for the life of a derailleur wears out the B spring, so it’s not a surprise that it can’t quite handle a 28t anymore.
Looks like Shimano claims 27 teeth max for the RD-4400.
But it looks like it was ridden a long time (enough to rust) before you noticed the issue? Or did you do something to it and then noticed the issue?