Anodized Nipple Failure
05-27-21, 01:21 AM
#26
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Originally Posted by cyccommute
There are some things you aren’t considering. First, no spoke/nipple should be assembled without spoke prep. The spoke prep serves as a insulator to prevent corrosion. This doesn’t 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, I’ve found far more frozen brass spoke nipples than aluminum. That’s mainly because the vast majority of spoke nipples are, and have been, brass. And, as I’ve said above, aluminum is used with generally used with more care and preparation than brass.
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, I’ve found far more frozen brass spoke nipples than aluminum. That’s mainly because the vast majority of spoke nipples are, and have been, brass. And, as I’ve said above, aluminum is used with generally used with more care and preparation than brass.
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.
05-27-21, 08:38 AM
#27
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Originally Posted by 79pmooney
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.
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.
05-27-21, 09:00 AM
#28
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Originally Posted by Chombi1
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.
I didn’t say the anodization was an “impregnable armor against corrosion”. 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 doesn’t 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.
Based on years of wheel building experience and years of riding those same wheels in winter conditions, I can tell you that, personally, I’ve 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 wasn’t 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 didn’t 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 I’ve 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.
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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.
05-27-21, 09:23 AM
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Originally Posted by Chombi1
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.
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.
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.
05-27-21, 09:28 AM
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Originally Posted by cyccommute
Aluminum spoke nipples are no more prone to corrosion, seizing, or galling than brass. I’ve 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. I’ve 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 don’t like square aluminum for that reason but I’m 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 I’ve used. Their pin vise nipple loader is also really nice, too. I’ve also lusted after their dishing tool for about 20 years...even seen one in the flesh...but can’t 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.
Yep. Splined nipples. I’ve 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 don’t like square aluminum for that reason but I’m 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 I’ve used. Their pin vise nipple loader is also really nice, too. I’ve also lusted after their dishing tool for about 20 years...even seen one in the flesh...but can’t 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.
05-27-21, 09:55 AM
#31
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Originally Posted by repechage
I do vote for Goofy there.
. Thanks to some fortuitous finds, I’ve even been able to use the color scheme on the shifters.
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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.
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.
