ennchicago

I've been doing some drivetrain cleaning on a new-to-me bike and have noticed some roughness/grinding in the lower jockey pulley on the Huret Duopar derailleur. (The pulley is smooth, not toothed.)

Is it safe/possible to open up the pulley and clean the bearings, or will I destroy a seal by doing so? If it's safe, is ordinary Phil's grease suitable here or do I need something lighter? Should I replace the pulley? (These do seem to be fairly readily available on eBay.)

Thank you in advance for any help.

bikemig 

Easy enough to open up; a bit of oil works well here. You're talking about a bushing, right?

Edit: here is a thread on huret duopar jockey wheels, https://www.bikeforums.net/classic-vi...key-wheel.html

ennchicago

No, not a bushing; I opened it up and there are definitely ball bearings.

RubeRad

I once disassembled, cleaned, greased, and reassembled toothless steel jockey wheels in a vintage campy rd, I bet yours is comparable. You can find pics here (mixed in with pics from the rest of the overhaul)

JohnDThompson 

BITD, almost all derailleur pulleys used ball bearings. Over the years, manufacturers started using bushings instead. Huret was one of the last hold outs with ball bearing pulleys, well into the 1980s even after Sachs purchased Huret.

Yes, it's perfectly fine to open it up and clean things out. But if the cones are pitted, you'll be hard-pressed to find replacements. In that case, replacing it with a bushing pulley or even one with a sealed cartridge bearing would be fine. The lower pulley on the Duopar is bog-standard, unlike the upper pulley.