RIMS Cromodoras/campys fitment

[Conserv]

8 hours ago, uai said:

No. Some are Electron (>=90%Mg, >9% Al) others are just normal alloy. Every Rim (unless it's billet) will probably be a blend of AL/Mg (and other Zn, Cu, Si etc..) Scales will tell what you've got.
However the "usual" ragnos are not Electron, the 7x13 40549 and 5,5x13 40512 are Electron.

Uli,

 

Wait. What?

 

The attached Campagnolo brochure (first photo) is from 1979, so clearly after the ‘02 era. But it clearly shows Campagnolo’s Elektron offerings as of 1979 (“Ultralight Elektron rims”). And a Ragno rim is shown in the first column, with 5 1/2” and 6” versions listed for e21’s.

 

So:

 

(a.) Is this only a partial listing of Campagnolo rims as of 1979, one that omits models, perhaps versions of the same design, made from something other than the Elektron alloy? or 

 

(b.) Did Campagnolo switch entirely to Elektron by 1979, whereas their earlier production was a mixture of alloys?

 

But if a Ragno is not Elektron before 1979, or other magnesium-based alloy, this still leaves me with questions. A 5 1/2” Ragno (model 40514) weighs 10 lbs (4.5 kilo.). That’s pretty light for what I would call a “meaty” casting. (This probably doesn’t translate well, but I’m distinguishing the thick-walled Ragno to a thin-walled Borrani bimetal — which is not a magnesium alloy!). And a bare Ragno oxidizes and corrodes much more rapidity, and much more dramatically, than a predominantly-aluminum rim. Old Ragno’s, with failed paint, frequently have facial pockmarks that one doesn’t typically find on predominantly-aluminum rims (second and third photos below).  After two months un-painted, a bare Ragno looks like living hell: dull and dark, with pitting “on the way”. After two months un-painted, a typical aluminum alloy rim looks… meh.

 

Could there be magnesium-alloy and aluminum-alloy Ragno’s? When I was looking for a restorer for my Ragno’s, I found an experienced and highly reputable Ferrari restorer who insisted that they, like the Ragno’s available as an option on Ferrari 246’s, were magnesium alloy and had to be kept painted to avoid the rapid and dramatic deterioration I’ve witnessed on Cromodora’s and Campagnolo’s?
 

I’m happy to be wrong as long as I learn something in the analysis! But let’s get whatever info we can out into the forum!

 

Thanks and regards,

 

Steve

 

 

 

[jimk]

Magnesium becomes the sacrificial element where galvanic corrosion conditions exist.  Road sale, moisture and the rim in contact with iron is the perfect mix.

Home water heaters have magnesium sacrificial anodes to be eaten up instead of the steel.

Lots of mystic, but a poor choice for an everyday tire rim.

[uai]

2 hours ago, Conserv said:

Could there be magnesium-alloy and aluminum-alloy Ragno’s?

 

Thanks and regards,

 

Steve

That's what I meant. Usual =Alu and unusual = electron
The "usual" are the ones I had in my hands and they were all too heavy for an electron wheel.
But It's not a a statistically sufficient amount. So all 3 sets I had physically in my hands were aluminium.
Cheers

Uli

Edited October 18, 2022 by uai

[Tbone1209]

9 hours ago, uai said:

No. Some are Electron (>=90%Mg, >9% Al) others are just normal alloy. Every Rim (unless it's billet) will probably be a blend of AL/Mg (and other Zn, Cu, Si etc..) Scales will tell what you've got.
However the "usual" ragnos are not Electron, the 7x13 40549 and 5,5x13 40512 are Electron.

So you said No. Electron is a blend of Mag and alloy.  I said "They are a blend of mag/alloy so with care and proper storage are fine with age." I suppose you are right. They are a blend of Mag and alloy which is a more accurate way to say what I said, which is they are a blend of Mag and alloy. Lol. This is all in the context of the wheels the OP showed which appeared to be 5.5 x 13 Ragno wheels....apparently left outside. 

 

I have 5 Ragno 5.5x13 wheels. Three from 77 and 2 from 72. The weight appears to be the same (I've yet to weigh them). They are light. They are close to NOS which is to say they have what appears to be the original finish with the BMW Opel stickers on the tire side. The key difference is the early wheels only have Campagnolo and the offset cast on the face whereas the later 77 wheels have the added KBA number. 

Edited October 18, 2022 by Tbone1209

[Conserv]

20 hours ago, uai said:

That's what I meant. Usual =Alu and unusual = electron
The "usual" are the ones I had in my hands and they were all too heavy for an electron wheel.
But It's not a a statistically sufficient amount. So all 3 sets I had physically in my hands were aluminium.
Cheers

Uli

Agreed, Uli: Casting the same rim in both aluminum alloy and magnesium alloy (Elektron in this case) would not be unheard of. An ad by Faza, a major and well-known U.S. dealer of Italian “hot-rod” automotive equipment, suggests that Stil-Auto offered the same rim in aluminum and magnesium. See the listing and rim highlighted in blue in the first photo.

 

”E)—Stil-Auto 6X13” aluminum/mag. same 6X13”

 

And weren’t the original Mini-Lites also offered in both aluminum alloy and magnesium alloy?

 

But this 1972 Faza ad, as well as other Faza ads of the same era (second photo with close-up in the third photo), also states that Faza was either only selling Elektron Campagnolos, or Campagnolo was only manufacturing Elektron rims. And many readers would read the ads’ texts and titles to state the latter, i.e., that Campagnolo only manufactured Elektron rims.

 

“All Campagnolos wheels have the same Elektron alloy and are manufactured the same way regardless of the intended use.”

 

Regardless of how one reads this ad language, you certainly weren’t buying aluminum alloy Campagnolos from Faza!

(Faza ads were contributed by c.d. some years back.)

 

Best regards,

 

Steve