Go Back  Bike Forums > Bike Forums > Classic & Vintage
Reload this Page >

Anodized Nipple Failure

Notices
Classic & Vintage This forum is to discuss the many aspects of classic and vintage bicycles, including musclebikes, lightweights, middleweights, hi-wheelers, bone-shakers, safety bikes and much more.

Anodized Nipple Failure

Old 05-27-21, 01:21 AM
  #26  
Chombi1 
Senior Member
 
Chombi1's Avatar
 
Join Date: Nov 2015
Posts: 3,834
Mentioned: 98 Post(s)
Tagged: 0 Thread(s)
Quoted: 1363 Post(s)
Likes: 0
Liked 459 Times in 316 Posts
Originally Posted by cyccommute View Post
There are some things you arenít considering. First, no spoke/nipple should be assembled without spoke prep. The spoke prep serves as a insulator to prevent corrosion. This doesnít always happen but aluminum spoke nipples are far more likely to be used in high end builds so more effort is up into preparation.

Second, aluminum nipples, especially colored ones, are anodized to make give them the color desired. The color is unimportant but the anodization is the oxidization of the aluminum to form an aluminum oxide layer. That is another layer of insulation.

Yes, aluminum is softer than brass but only just. On the Mohs hardness scale, aluminum has a harness of 2.5 to 3. Brass has a hardness of 3.

Finally, Iíve found far more frozen brass spoke nipples than aluminum. Thatís mainly because the vast majority of spoke nipples are, and have been, brass. And, as Iíve said above, aluminum is used with generally used with more care and preparation than brass.
The anodizing oxide layer is something like 1 micron thick. Easily scratched when just putting a spoke wrench against the flats on an aluminum spoke nipple, especially when you get to the final tensioning phase of building a wheel when the pressure against those flats are the greatest. Once that anodized "skin" is broken you have raw aluminum exposed to the elements which where corrosion starts. So you cannot really consider anodizing as some sort of impregnable armor against corrosion when dealing with spoke nipples.
As for spoke prep, yes, you have that lubricant present during wheel building which can initially provide some isolation between the spokes snd the nipples, but then that spoke prep compound does eventually dry out and go away with miles and exposure to the elements. And that's when corrosion/seizing between the steel spoke and the aluminum nipple threads starts.
Chombi1 is offline  
Old 05-27-21, 08:38 AM
  #27  
Mr. Spadoni 
Senior Member
Thread Starter
 
Join Date: Jan 2015
Posts: 633
Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 234 Post(s)
Liked 183 Times in 100 Posts
Originally Posted by 79pmooney View Post
No, the colors are located relative to the vessel. So if you see green you are looking at the starboard (right) side of the ship whether it is going forward or backwards. If you see both, you know you are in front of it. (The running lights, red and green, only shine to the sides and forward, not back. Back is a white light.)

This gives a captain very good information about what he is seeing at night and can therefore calculate or observe whether they are on a collision course. They also indicate which ship has right of way and is to hold its course and which is to yield. Important stuff when the actions to avoid collision may have to be taken a mile in advance.
Well, thereís one more thing that I can file under ďstuff my older brother told me but wasnít quite right.Ē
Mr. Spadoni is online now  
Old 05-27-21, 09:00 AM
  #28  
cyccommute 
Mad bike riding scientist
 
cyccommute's Avatar
 
Join Date: Nov 2004
Location: Denver, CO
Posts: 25,211

Bikes: Some silver ones, a red one, a black and orange one, and a few titanium ones

Mentioned: 136 Post(s)
Tagged: 1 Thread(s)
Quoted: 4844 Post(s)
Liked 2,398 Times in 1,419 Posts
Originally Posted by Chombi1 View Post
The anodizing oxide layer is something like 1 micron thick. Easily scratched when just putting a spoke wrench against the flats on an aluminum spoke nipple, especially when you get to the final tensioning phase of building a wheel when the pressure against those flats are the greatest. Once that anodized "skin" is broken you have raw aluminum exposed to the elements which where corrosion starts. So you cannot really consider anodizing as some sort of impregnable armor against corrosion when dealing with spoke nipples.
The anodized layer can vary from 1 Ķm to 100 Ķm depending on the process used for anodization. Itís not all that easy to scratch either. Aluminum oxide has a hardness of 9 on the Mohs hardness scale...only diamond is harder. The underlying aluminum is soft and the alumina coating is brittle but itís still pretty tough. It also doesnít matter if the outside of the nipple is damaged. Thatís not where the corrosion is a problem. Aluminum is also reactive so any exposure of the aluminum is quickly...almost instantaneously...oxidized.

I didnít say the anodization was an ďimpregnable armor against corrosionĒ. But it does serve as an insulating layer that slows galvanic corrosion. Corrosion of spokes and spoke nipples are driven by chloride erosion of the materials and all three materials...steel, brass, and aluminum...are highly susceptible to chloride ions corrosion. If you ride a bike in winter conditions, road salt exposure is going to corrode spoke nipples no matter what the material. One doesnít have an advantage over the other.

As for spoke prep, yes, you have that lubricant present during wheel building which can initially provide some isolation between the spokes snd the nipples, but then that spoke prep compound does eventually dry out and go away with miles and exposure to the elements. And that's when corrosion/seizing between the steel spoke and the aluminum nipple threads starts.
Every spoke prep compound Iíve used from linseed oil to Wheelsmith spoke prep to the Fix spoke prep I referenced above is made of materials that donít ďdry outĒ or evaporate over time. First, all of them are ďdryĒ to begin with. Second, the compounds donít have an appreciable vapor pressure so here is no way for them to evaporate. Third, the spoke prep is trapped inside the threads of the nipple and arenít exposed to the elements. Fourth, these compounds donít have an appreciable water solubility. If youíve ever tried to remove dried linseed oil or Wheelsmith spoke prep from a spoke, youíd know what Iím talking about.

Based on years of wheel building experience and years of riding those same wheels in winter conditions, I can tell you that, personally, Iíve never had a spoke of any material seize due to corrosion. I recently disassembled a decades old wheel se to salvage the hubs. The wheel wasnít one I built but I did use the wheel for many years as a winter wheel. It had anodized spoke nipples...purple ones...but it came apart very easily. I didnít even have to lubricate the nipples before unscrewing them.

Just to be clear, using a spoke prep...even just linseed oil...and oiling the nipples while building will go a very long way towards preventing corrosion. The vast majority of spoke nipples that Iíve had to deal with that are seized due to corrosion are OEM wheels where no spoke preparation or lubrication has ever been used. I often tell clients at the local co-op to use a drop of Triflow on each spoke nipple before they start to true an old wheel...or even a new one for that matter. Corrosion and binding of spoke nipples is more a matter of improper wheel building than it is of the material used in making the spoke nipple.
__________________
Stuart Black
Gold Fever Three days of dirt in Colorado
Pokin' around the Poconos A cold ride around Lake Erie
Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
Days of Wineless Roads. Bed and Breakfasting along the KATY
Twisting Down the Alley. Misadventures in tornado alley.
cyccommute is offline  
Old 05-27-21, 09:23 AM
  #29  
repechage
Senior Member
 
Join Date: Jun 2006
Posts: 17,389
Mentioned: 113 Post(s)
Tagged: 0 Thread(s)
Quoted: 2386 Post(s)
Liked 1,306 Times in 986 Posts
Originally Posted by Chombi1 View Post
The anodizing oxide layer is something like 1 micron thick. Easily scratched when just putting a spoke wrench against the flats on an aluminum spoke nipple, especially when you get to the final tensioning phase of building a wheel when the pressure against those flats are the greatest. Once that anodized "skin" is broken you have raw aluminum exposed to the elements which where corrosion starts. So you cannot really consider anodizing as some sort of impregnable armor against corrosion when dealing with spoke nipples.
As for spoke prep, yes, you have that lubricant present during wheel building which can initially provide some isolation between the spokes snd the nipples, but then that spoke prep compound does eventually dry out and go away with miles and exposure to the elements. And that's when corrosion/seizing between the steel spoke and the aluminum nipple threads starts.
Reminds me of the long lost Batfink Cartoon, character, "my wings are like a shield of steel"
not a fan of alloy nipples that I have encountered so far.
The friction of the spoke nipple against the rim will scratch the anno off directly.
Will win on styling points when new.

on a sailboat, the typical sound turnbuckle is stainless to bronze. Stainless to aluminum, anti-galvanic paste between.

Last edited by repechage; 05-27-21 at 09:27 AM.
repechage is offline  
Old 05-27-21, 09:28 AM
  #30  
repechage
Senior Member
 
Join Date: Jun 2006
Posts: 17,389
Mentioned: 113 Post(s)
Tagged: 0 Thread(s)
Quoted: 2386 Post(s)
Liked 1,306 Times in 986 Posts
Originally Posted by cyccommute View Post
Aluminum spoke nipples are no more prone to corrosion, seizing, or galling than brass. Iíve had to deal with plenty of brass spoke nipples that are all three. Brass is not inert to salt corrosion. Any spoke nipple benefits from a spoke prep compound and oiling while building. Oiling while tuning will help too.



Yep. Splined nipples. Iíve been building with them for about 5 years now. They are very nice and work very well. The spline makes the spoke wrench engagement much more positive...no more rounded off nipples. I donít like square aluminum for that reason but Iím not much more of a fan of square brass, either. Aluminum does have the advantage of colors. You can do goofy stuff like this


But the red/blue/yellow/green matches the rest of the bike.



While at Wheel Fanatyk, get some Fix spoke prep which is the best spoke prep Iíve used. Their pin vise nipple loader is also really nice, too. Iíve also lusted after their dishing tool for about 20 years...even seen one in the flesh...but canít quite justify the cost.

I have, by the way, had a lot of problems with Specialized OEM wheels with aluminum nipples but they break at the spoke because they are using spokes that are too short.
I do vote for Goofy there.
repechage is offline  
Old 05-27-21, 09:55 AM
  #31  
cyccommute 
Mad bike riding scientist
 
cyccommute's Avatar
 
Join Date: Nov 2004
Location: Denver, CO
Posts: 25,211

Bikes: Some silver ones, a red one, a black and orange one, and a few titanium ones

Mentioned: 136 Post(s)
Tagged: 1 Thread(s)
Quoted: 4844 Post(s)
Liked 2,398 Times in 1,419 Posts
Originally Posted by repechage View Post
I do vote for Goofy there.
Thanks. Thatís just the latest addition. The whole 4 color thing started when I found cable donuts of various colors at my local co-op. Iíve repeated the pattern throughout...even in the valve caps. Thanks to some fortuitous finds, Iíve even been able to use the color scheme on the shifters.
__________________
Stuart Black
Gold Fever Three days of dirt in Colorado
Pokin' around the Poconos A cold ride around Lake Erie
Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
Days of Wineless Roads. Bed and Breakfasting along the KATY
Twisting Down the Alley. Misadventures in tornado alley.
cyccommute is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright © 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.