I am trying to put a neglected bicycle back on the road. It has a pedals marked with W. GermanyK10491. Google search revealed that they are Union K10491 pedals. I have found good pictures on ebay. My pedals are almost the same. A bit more rust, one dust cap missing and the other rusty and dented. But in it better days it might resemble the dust caps one the pictures.

Since the pedals were almost siezed I took them apart. Ball bearings did not look too bad. No spalling, almost shiny grey color. The grease had a healthy consistency of dried up clay and a color of pitch tar. What puzzles me that the ball bearings inside (10 per bearing) were roughly 3.68 mm in diameter. Measured with vernier caliper. A Sheldon's crib sheet http://www.sheldonbrown.com/cribsheet-metric.html says there is no such dimension used regularly in bicycle world. It says most pedals use 5/32" balls.

So, do these pedals use funny ball bearings? Perhaps someone changed the bearings and put in there what ever he had by hand at the moment. Also, front and rear hubs have funny sized bearings also, which would support this hypothesis. Third possibility is that ball bearing wore down from 5/32" down to 3.68 mm. I find that last one pretty hard to swallow. Is it possible for bearings to wear this much?

Can anybody tell me what is the correct size and number of bearings for these pedals?

Good pictures of pedals are on ebay.

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