Hello All: After making a holy mess of a rear CB750 Hub, I decided to get a proper tool to remove the Bearing Retainer ring. (First I didn't know to drill out the punch marks that serve as a lock to the retainer, learned that from a searech on this site...AFTER I had screwed it up.
) I did a web search on pin spanners. Came up with a lot of bicycle tools which may work but didn't seem beefy enough. Then some automotive ones which were way cool, but pricey in the $65+ and up range.
So following many suggestions here, I inventoried my resources. I came up with a length of wheelbarrow handle and two nails used to build concrete forms.
The nails are double headed, one to drive the nail and the second to seat the nail without burying it. That way the framer can get his pry bar on it and take the form apart easily. I cut the drive head off, leaving a pin of nearly exactly the right size. Then measured the center to center spread of the pin holes in the retainer with a caliper, transferred it to the wooden handle and drilled two holes slightly smaller than the nail. That way I could drive the nails in without them drifting apart or closer together. Sawed off the pointy bits and voila!
I tested it on a spare hub, which had no wheel making it harder to hold. By placing the hub on the neoprene floor mat, the tool in the retainer, my knee on the tool to hold it in, and a slight tap with a hammer, the ring turned easily and spun the rest of the way out with just the leverage of the tool.
I will rotate the handle 90 degrees and do it again for the front retainer, the pins are closer together.