I have a Stronglight Delrin headset, called B10. The aluminum nut is marked with the name “ B. Hinault,” certainly a famous name. It came on my Trek 610 from 1984, and is listed on Vintage-Trek as the original equipment for the 1984 Trek 610. It’s complete except for the top washer, and I’d like to use it in on my Woodrup rebuild. The B10 is a very similar design to the classic all-aluminum A9, but with the threaded race, upper pressed cup, lower pressed cup, and he crown race made of Delrin rather than aluminum. The Delrin parts were originally deep shiny place, but are now discolored to matte grey with some roughness. Has anybody else had this problem and have any of you been able to restore the finish of the parts to solid shiny black? The bearing seats, bearing races, and the rollers are in excellent condition, after more than 40 years!

The Woodrup used to wear a steel Campy Record headset from the ‘70s or ‘80s. I’ve replaced these with Stronglight A9 in the past with no problems. I’m The dimensions of the B10 (stack heights are the key sizing) are certainly very close.

i haven’t tried many possible solutions, such as solvents and thinners, but I know soap and hot water does not work. I’m first looking to gather up some existing experience.

Anybody have a sense for the chemistry of Delrin? Has it oxidized? Is it similar to Nylon? Can any finish or varnish stick to the Delrin and seal it? Can I just paint it black? Will Testors stick?