Noticed this when changing the chain. I tried to snug up that bolt holding the wheel onto the rear derailleur, but it's already tight. The other wheel doesn't have this kind of play. I'm assuming this is a problem, but I'm not sure what to do about it.
Jockey Wheel Lateral Play
byu/MisanthropicAnthro inbikewrench
by MisanthropicAnthro
8 Comments
Jockey wheels need to be replaced every so often. This one looks like it’s worn enough to need it. I’ve seen some real gums, but the wear on this one seems to be where the bushings are.
Replace
Replace it.
You can get spare/new jockey wheels. It’s common enough for them to go eventually, well done on riding your bike so much! With that much play it’s unlikely that this one can be easily salvaged.
Web search, or someone will come up with the compatibility details shortly.
It’ll help your shifting immensely when it’s the upper jockey wheel at fault.
This era of 105 still had the “Centeron” pulley. Some lateral movement was built into the upper pulley, allowing to center under the cog if a shift went almost but not quite right. But the amount of play in the footage is way too much; that’s worn out. Replace the pulley and its bushing with parts from a less-worn derailleur of the same era (mid to late 80s), which you can likely find at a co-op/nonprofit shop.
It’s normal for the guide pulley to have some more play than the tension pulley but that’s too much, almost like its missing the bushing/bearing
It doesn’t have to be the identical part. Almost any wheel of similar size will work. Anyway, you’ll find out pretty quickly if it doesn’t.
https://preview.redd.it/h7hs7bvh4djg1.jpeg?width=3024&format=pjpg&auto=webp&s=f070ac6378bda6c64ec18384ff91571a7d0c96a5
Took it off the bike. The root cause of the wobble seems to be that the tubular piece (left) has significantly smaller outer diameter than the inner diameter of the center of the pulley where it sits.