Offered for your consideration , is the fact that an anodized part which happens to become scratched , can not easily have the scratch polished away , even BEFORE it leaves the factory .
I always thought the lack of anodizing on certain aluminum parts had something to with those aluminum parts being held , tightly clamped by large machines , while pieces of steel were pressed into them .
The pressing operation could easily result in scratches , and once the steel pieces were in place that part could not be anodized .
Hubshells have the steel bearing races ( cups ) pressed in .
Front derailleurs have the steel pins pressed in .
Rear derailleurs . . . ?
Seat posts . . . ?
Raoul Delmare
Marysville Kansas
> Why are some of the SR/NR parts anodized and some are not?
>
> If you read my previous post (repro'd below) you'll see that there would
> seem to be no reason not to anodize all the aluminum parts in the group.
> All advantages and no disadvantages, right? Anodizing is not, BTW, a
> good bearing surface, does not increase the strength of aluminum part,
> and resists scratching but only to a very small degree.
>
> There are only a few parts that aren't anodized: Seat post, pedal
> bodies, hubs, shift levers, and front derailleur body and arms.
>
> My educated guess? If the part is likely to get scratched (or worn) it
> was not anodized. If an anodized part gets scratched your only recourse
> is to strip the anodizing, polish out the scratch and then reanodize the
> part. If the part is not anodized and gets scratched, you just polish
> the part and it looks good again.
>
> The seat post and pedal bodies are the prime example of parts that get
> badly scratched (seat post by insertion, and the pedal body by being
> kicked and stepped on to flip right side up) and can be made to look
> good again by polishing.
>
> So why are hubs not anodized (they are not subject to scratching after
> all)? The story I heard was that the pro mechanics liked to be able to
> shine them up (shinier than you get with anodizing) as a matter of pride.
>
> Shift levers? Maybe all the raised bumps and letters would get quickly
> worn through with all the hand contact of shifting? But the brake
> levers get a lot of handling too and are anodized. Don't know.
>
> The front derailleur body and arms? Don't know. You'd think it would
> be anodized to match the rear derailleur but it isn't.
>
> One last point: The cranks are anodized, but not because it keeps them
> from galvanic fusing onto the BB axle as was stated in a previous post.
> Anodizing will not occur inside a hole for the same reasons you cannot
> chrome plate inside a hole unless you use special fixturing. Examining
> the interface between the axle and the crank will show that there is no
> barrier such as anodizing (which wouldn't hold up anyway actually).
>
> Please let's hear your theories...
>
> Chuck Schmidt
> South Pasadena, CA
>
>
> Old post:
> ========================================================================
> Date: Mon, 17 Feb 2003 19:47:41 -0700
> From: Chuck Schmidt <chuckschmidt@earthlink.net>
> Subject: [CR]Campagnolo Nuovo Record and Super Record anodizing
>
> There seems to be lots of confusion on just which aluminum parts in a
> Nuovo or Super Record are anodized. This comes up when questions about
> how best to clean the parts when finding an old bike.
>
> First, some anodizing info...
>
> Definition:
> Anodizing is the successful development and control of a natural
> oxidation process that occurs when aluminum is exposed to the
> atmosphere. Electricity and chemicals are used jointly to produce a
> hard, transparent surface that is integral with base aluminum.
>
> Anodizing Basics:
> Aluminum is anodized for corrosion resistance, abrasion resistance,
> insulation from electricity, adhesion, or aesthetic enhancement.
>
> Characteristics:
> . Hard, comparable to a sapphire
> . Transparent, similar to glass
> . Insulative and static-resistant
> . Wide variety of colors and finishes
> . Integral with aluminum surfaces, non-flaking
>
> Now, which aluminum parts are anodized and which aren't:
>
> Hubs - no
> Pedal bodies - no
> Pedal cages - yes
> Headset - yes
> Rear derailleur - yes
> Front derailleur - no
> Cranks - yes
> Chainrings - yes
> Brake levers - yes
> Brake calipers - yes
> Shift levers - no
> Seat post - no
>
> Incidentally, when the Super Record group first made the rounds of the
> trade shows circuit, the head set, chainrings, and bottom bracket cups
> were black anodized. The production versions were clear anodized.
>
> The non anodized parts can be cleaned and polished (and protected) with
> Semichrome, Wenol, Mothers, etc.
>
> The anodized parts can be cleaned with degreaser, solvent, WD-40, soap
> and hot water, etc.
>
> A simple test to see if an aluminum part is anodized or not. Put a
> little dab of Semichrome (my personal favorite) on a white cloth and rub
> the part a little. If there is a black deposit on the cloth that means
> that there has been a chemical reaction with the aluminum. If the part
> is anodized, there will be no change in the polish on the cloth because
> there has been no reaction (and absolutely no damage to the anodizing).
>
> Now the QUESTION: Why are some of the parts anodized and some are not?
> Class? Anyone?
>
> Chuck Schmidt
> South Pasadena, Southern California
> http://www.velo-retro.com (Campagnolo Timeline, reprints & t-shirts)
>
> .