In my earlier post about spokes, I wrote that DT, Hoshi (star), and Sapim stainless steel spokes are "technically not stainless steel,"
but that's just because they're a bit weak in corrosion resistance for the name "stainless" (rust-less) to be strictly accurate.
That said, they are a type of stainless steel (whatever that means).
Stainless steel refers to steel mixed with chromium, or with both chromium and nickel.
Stainless steel made with chromium and nickel is non-magnetic,
meaning magnets don't stick to it.
Stainless steel kitchen sinks are all made this way. Chromium + nickel stainless steel
has excellent corrosion resistance (doesn't rust easily), so it's perfect for areas with water.
However, it's inferior to chromium-type steel in tensile strength.
High tensile strength = when used as a spoke, the head is less likely to snap off.
Chromium-type stainless steel attracts magnets (with some exceptions).
So by holding a magnet nearby, you can determine whether the stainless steel is chromium-type or chromium + nickel-type.
Since chromium-type has higher tensile strength, to put it bluntly:
"The more strongly a magnet sticks to a spoke, the less likely it is to snap at the head, but the more it will rust."
↑This is DT's Champion 2.0.
Let me try lifting it with a magnet from a Cateye (speed sensor magnet).
The magnet sticks to it. But if I lift it any higher,
the magnetic force can't support the weight of a single spoke, and it falls.
I held the magnet against a bundle of Champion spokes, but it won't lift them.
Spoke makers usually stamp a mark on the head that identifies the manufacturer.
This one's a bit hard to read, but
↑it's stamped with "DT" like this.
Next, Hoshi's Starbright.
This is a discontinued Aero Starbright Type 3, which has flattening treatment.
A plain Starbright also exists.
In Hoshi's case, separate from the Starbright, there's a spoke with the model name "Stainless Steel Spoke."
This one doesn't react to magnets at all.
The Starbright is broadly speaking a type of stainless steel material-wise, but
it's clearly a specially formulated material that's deliberately made different.
It sticks super hard!
The spoke head has an "H" inside a circle.
The Stainless Steel Spoke (Hoshi's model name) has a ☆ star mark inside a circle, so you can tell them apart at a glance.
The Stainless Steel Spoke (Hoshi's model name) lives up to its name as a stainless steel spoke,
and is a spoke that snaps at the head very easily.
Since I don't normally stock them, I can't get a photo.
Next is Sapim's CX-RAY.
This also sticks pretty "Snap!" with the magnet, just like the Starbright.
Even if I swing it around while attached to the magnet, it doesn't fall.
Sapim doesn't have a stamp on the spoke head.
Here it says "SAPIM."
When a spoke snaps at the head, the stamped part flies off, so
you can't tell which manufacturer made it just by looking at the broken spoke alone.
Sapim puts their name in a location that survives breakage,
basically saying with full confidence,
"Our spokes don't break, so it's fine to put our name here."
Of course there are cases of CX-RAY head failures, but
statistically they're very rare.
The Wheelsmith aero spoke also attracts the magnet quite well.
This W-free rear wheel has lots to write about, so I'll cover that another day.
DT spokes have weaker magnet attraction, but to be fair, DT's Champion is
a very head-break-resistant spoke. Depending on the wheel type and building method, there are even cases where I think it might theoretically be better than the CX-RAY.
In fact, one of my rear wheels has Champion on the freewheel side and CX-RAY on the opposite side.
Magnet stickiness is a rough indicator of tensile strength in terms of material,
but spoke head-snap resistance isn't determined by that alone.
However, it's definitely true that stainless steel spokes that magnets won't stick to at all snap at the head frequently.
but that's just because they're a bit weak in corrosion resistance for the name "stainless" (rust-less) to be strictly accurate.
That said, they are a type of stainless steel (whatever that means).
Stainless steel refers to steel mixed with chromium, or with both chromium and nickel.
Stainless steel made with chromium and nickel is non-magnetic,
meaning magnets don't stick to it.
Stainless steel kitchen sinks are all made this way. Chromium + nickel stainless steel
has excellent corrosion resistance (doesn't rust easily), so it's perfect for areas with water.
However, it's inferior to chromium-type steel in tensile strength.
High tensile strength = when used as a spoke, the head is less likely to snap off.
Chromium-type stainless steel attracts magnets (with some exceptions).
So by holding a magnet nearby, you can determine whether the stainless steel is chromium-type or chromium + nickel-type.
Since chromium-type has higher tensile strength, to put it bluntly:
"The more strongly a magnet sticks to a spoke, the less likely it is to snap at the head, but the more it will rust."
↑This is DT's Champion 2.0.
Let me try lifting it with a magnet from a Cateye (speed sensor magnet).
The magnet sticks to it. But if I lift it any higher,
the magnetic force can't support the weight of a single spoke, and it falls.
I held the magnet against a bundle of Champion spokes, but it won't lift them.
Spoke makers usually stamp a mark on the head that identifies the manufacturer.
This one's a bit hard to read, but
↑it's stamped with "DT" like this.
Next, Hoshi's Starbright.
This is a discontinued Aero Starbright Type 3, which has flattening treatment.
A plain Starbright also exists.
In Hoshi's case, separate from the Starbright, there's a spoke with the model name "Stainless Steel Spoke."
This one doesn't react to magnets at all.
The Starbright is broadly speaking a type of stainless steel material-wise, but
it's clearly a specially formulated material that's deliberately made different.
It sticks super hard!
The spoke head has an "H" inside a circle.
The Stainless Steel Spoke (Hoshi's model name) has a ☆ star mark inside a circle, so you can tell them apart at a glance.
The Stainless Steel Spoke (Hoshi's model name) lives up to its name as a stainless steel spoke,
and is a spoke that snaps at the head very easily.
Since I don't normally stock them, I can't get a photo.
Next is Sapim's CX-RAY.
This also sticks pretty "Snap!" with the magnet, just like the Starbright.
Even if I swing it around while attached to the magnet, it doesn't fall.
Sapim doesn't have a stamp on the spoke head.
Here it says "SAPIM."
When a spoke snaps at the head, the stamped part flies off, so
you can't tell which manufacturer made it just by looking at the broken spoke alone.
Sapim puts their name in a location that survives breakage,
basically saying with full confidence,
"Our spokes don't break, so it's fine to put our name here."
Of course there are cases of CX-RAY head failures, but
statistically they're very rare.
The Wheelsmith aero spoke also attracts the magnet quite well.
This W-free rear wheel has lots to write about, so I'll cover that another day.
DT spokes have weaker magnet attraction, but to be fair, DT's Champion is
a very head-break-resistant spoke. Depending on the wheel type and building method, there are even cases where I think it might theoretically be better than the CX-RAY.
In fact, one of my rear wheels has Champion on the freewheel side and CX-RAY on the opposite side.
Magnet stickiness is a rough indicator of tensile strength in terms of material,
but spoke head-snap resistance isn't determined by that alone.
However, it's definitely true that stainless steel spokes that magnets won't stick to at all snap at the head frequently.