Derailleur Idler Pulley Grinding

[Hayden0101]

Hello, the rear derailleur idler pulley is grinding on the casette. The grinding only happens when I shift it to first gear. I have tried adjusting the limits, B screws, and cable tension, yet the grinding still persists. Thank you to whoever responds.

 

[Sharky]

First gear? Do you mean the largest or smallest sprocket?
Better experts than me, might be able to advise, if you tell us the cassette size and the RD type.

Also what's at the front? A double? And does it happen on both chain rings?

Good luck in trouble shooting.

 

[Hayden0101]

First gear? Do you mean the largest or smallest sprocket?
Better experts than me, might be able to advise, if you tell us the cassette size and the RD type.

Also what's at the front? A double? And does it happen on both chain rings?

Good luck in trouble shooting.

Thanks for the reply, I do mean the largest rear sprocket. The rear derailleur is a medium cage. Cassette: 5 cog 14-28T and chainring: 3 cog 28-48T.

 

[Ajax Bay]

Make and model of RD please? The set up should be fine and one which served those riding in the 70s and early 80s fine. The pulley nearest the sprockets is the guide pulley btw: it's not in the slightest bit 'idle'.
If you really have screwed in the 'B' screw to its fullest extent without adequate effect, you can remove it and screw it in from the opposite direction to achieve the aim.

 

[Hayden0101]

Make and model of RD please? The set up should be fine and one which served those riding in the 70s and early 80s fine. The pulley nearest the sprockets is the guide pulley btw: it's not in the slightest bit 'idle'.
If you really have screwed in the 'B' screw to its fullest extent without adequate effect, you can remove it and screw it in from the opposite direction to achieve the aim.

Shimano Model #RD-TZ20 HE. I tried removing the B screw and screwing it in the other side and it didn't move it enough.

 

[Sharky]

Another couple of question -
Has it always been like this or only recently?
Has anything been changed recently? Wheel taken off, new cassette, new chain etc?
Does it make the same noise on all three of the chainrings?

 

[Cycleops]

If it was fine previously it sounds like something has happened to the derailleur, likely worn. A new one would solve it but someone more versed in RD problems could maybe suggest what has worn and if it can be fixed.

to CC

 

[Hayden0101]

Another couple of question -
Has it always been like this or only recently?
Has anything been changed recently? Wheel taken off, new cassette, new chain etc?
Does it make the same noise on all three of the chainrings?

I just setup the bicycle since it had no rear derailleur. The noise happens on all three chainrings and when I shift to a larger cog on the chainring the sound gets worse.

 

[antnee]

Seems like you've got a bit of a problem perhaps if you put a picture up? Also I'm presuming the bike had a RD on before or else you'd not have fixings for the derailleur hanger, having had somewhat similar problems when I converted from 8 speed cassette to a 9 I found the basic problem was the B screw wasn't long enough so fitted a longer one which soon moved the guide pully away from the sprockets .( as did put a 11-34 cassette on in place of a 12-28) Let us know how you get on with it.

 

[Cycleops]

I suspect what has happened is that the derailleur you've fitted is not a match (in capacity) for the cassette/ freewheel you have.
In which case you need to either change the derailleur to one that can handle range of the cassette or change the cassette to one that can work within the capability of the derailleur.

 

[Paulus]

I suspect what has happened is that the derailleur you've fitted is not a match (in capacity) for the cassette/ freewheel you have.
In which case you need to either change the derailleur to one that can handle range of the cassette or change the cassette to one that can work within the capability of the derailleur.

Might need a long cage derailuer.

 

[Ajax Bay]

I suggest any RD will cope with a 14-28 (5sp) block, certainly as far as largest sprocket is concerned (chain wrap capacity a different parameter).
Shimano RD-TZ20 HE is part of the Tourney range: very widely used.