Just to be clear, I was discussing the currently manufactured black painted Stronglight A9 steel headsets. They are currently selling on eBay for $16 to $30. You get what you pay for!

Aside from the black painted surface vs. chromed plating, they're most likely case hardened low quality steel with unground bearing races.

The original aluminum A9 headsets were much better quality than the cheap black steel ones. The new ones with the sealed cartridges are even better made than the original A9s. They're selling for ~$60.

A cheap headset lower bearing cup. Notice the rough surface of the chrome plating in the bearing races.



Precision ground bearing races in a quality headset cup.



Caged headset bearings. One problem with cages is the tend to keep the balls in the same position which increases the likelihood for indenting via wear and/or impact.


Indented crown race


The indentations most frequently occur in the crown race and lower headset cup. They are located in the same position in both parts which results in "indexing". There's a cheap temporary fix for indexing. Remove the fork and remove either the bottom head tube cup or crown race. Rotate it a few degrees and reassemble.

verktyg