This is the second in my series of posts on current rim trends.
It seems like hard-anodized aluminum rims are becoming more common.
Anodized aluminum simply means a coating of aluminum oxide. Thin coatings are often combined with dye to produce cosmetic anodizing. A thicker layer of undyed aluminum oxide forms the grey "hard anodizing" that was common on many rims in the 1980s and 1990s.
At the time, hard-anodizing was marketed to "increase strength" and "increase stiffness" and "increase brake track durability." Turns out to have minimal effect on strength or stiffness of a built-up wheel, and
Jobst Brandt claims that the hard brittle coating increases the risks of cracks propagating through the softer aluminum. The brake track is indeed more durable, but that's because it provides worse braking until the hard coating wears away and the brake pads can contact the bare aluminum underneath.
Keith Bontrager isn't quite as confident as Jobst on the cracking-risk, but also sees zero functional benefits to hard-anodizing.
It seems to me that the main value of hard-anodizing is cosmetic, either for people who like the look for a certain kind of period-correct, or for people who get annoyed by shiny aluminum showing dirt and scratches.
Given the critiques and lack of benefit, hard-anodized rims seem to have died off for awhile.
However, they are apparently becoming more common. Many newer rims, such as the HPlusSon TB14 or Archetype, are available in hard-anodized coating, and silver (bare/polished aluminum finish) rims are becoming less common.
I'm curious whether the conventional wisdom that I learned - e.g., Jobst's claims of no advantage, only disadvantage for hard anodized rims - has been overturned. Or, are we simply seeing a resurgence because some people like the look, and the disadvantages are fairly minimal?
Note: I'm curious why hard-anodized rims seem to be making a comeback, and whether aggregate opinion on the value/downsides has changed. Not wanting this to become anecdote city of "I had a good experience with my hard-anodized Weinmann rims" or "my Mavic MA40 cracked at the drive-side eyelets."