Identification Please

[BarkerBrown]

While fiddling with my gear cable this little fellow dropped out. I think it might go on the spring end in the gear adjuster?

[gregoryoftours]

Were you adjusting your gear cable at the derailleur, shift lever or frame mounted barrel adjuster? It looks a bit like a hard stop that a threaded barrel adjuster might come up against when screwing into the rear derailleur. If you're running that adjuster without the plastic surround/spring it might allow it to screw in far enough to push that stop through.

[BarkerBrown]

Were you adjusting your gear cable at the derailleur, shift lever or frame mounted barrel adjuster?

The rear black adjuster. I don’t think now (having seen various diagrams) that the little component was from the adjuster.

[gregoryoftours]

Did it definitely come off the bike as you adjusted the gears? Hard to say without scale but it could also just be a roller from a chain. If it came from your rear derailleur it will have been pushed out of the threaded part of the rear mech, it's not a part of the barrel adjuster itself, the barrel adjuster may have driven it out of place and it won't be in any diagram as a separate part because it's not supposed to be a separate part.

[cycleruk]

My immediate thought it looked like a roller from one of the derailleur pullies. ?
What's the diameter ?

[gregoryoftours]

This is the part I'm talking about:

in the first picture you can see I've pushed it partly out of the derailleur - normally it would be fully recessed inside the aluminum. Second picture it's fully driven out. Press it back in with a pair of channel lock pliers. The derailleur will work fine without it but it's better in than out. The one edge of the inner hole of the ring is chamfered so that a cable running over it at extreme angles won't either saw away at the aluminum without this insert in place, or won't get frayed running repeatedly over the steel edge. Therefore press it back in so the chamfer is on the exit side.

[simonineaston]

re the first photo, without an indication of scale, it's harder to judge... a ruler, or if none handy, a coin alongside, would help.

[BarkerBrown]

This is the part I'm talking about: IMG_20230604_153140.jpgIMG_20230604_152943.jpg
in the first picture you can see I've pushed it partly out of the derailleur - normally it would be fully recessed inside the aluminum. Second picture it's fully driven out. Press it back in with a pair of channel lock pliers. The derailleur will work fine without it but it's better in than out. The one edge of the inner hole of the ring is chamfered so that a cable running over it at extreme angles won't either saw away at the aluminum without this insert in place, or won't get frayed running repeatedly over the steel edge. Therefore press it back in so the chamfer is on the exit side.

Yes, that’s the one. Thank you so much. Been scratching my head all day and have reassembled without this part. Will get it sorted tomorrow.

Much obliged to everyone taking the time to help.

[rjb]

Well that's a first for me. I've never seen one of those rings come out before.