Regarding DT's Revolution spokes,
I'll talk about this from the builder's perspective rather than the rider's experience.
Before that.
There's an article I wrote about the threads on Ritchey's WCS stem
so please take a look. (→here)
That linked article was written by me a long time ago.
Among the 10 strength grades of JIS-standard screws,
the top 3 on the strong end are:
8.8 screws break at 80kg, and don't stretch beyond 64kg (80% of that).
10.9 screws break at 100kg, and don't stretch beyond 90kg (90% of that).
12.9 screws break at 120kg, and don't stretch beyond 108kg (90% of that).
That's what it means.
For example, on this Vision's TT bar,
the fixing screws on the arm pad bracket have a 10.9 marking.
This means they're not ordinary screws but "spec screws"
engineered to target strength properties within a very narrow range.
If you keep tightening a stem's screws beyond their limit, stretching occurs.
Eventually they'll break.
If you look closely at the threads of a stretched stem screw,
the pitch of the threads below the neck (the part that doesn't enter the threaded hole)
sometimes becomes uneven.
This preamble is long, but the point I'm making is
that both screws and spokes experience stretching.
I calculate spoke length using my own custom formula.
Many of the calculation formulas you find online have errors,
and special spoke patterns require correction values,
but I've never seen a formula that covers all of that.
My calculated spoke length is
the length where the spoke end and nipple end should be flush.
The images above show the actual state of a finished wheel build.
The other day, while building a wheel with DT Competition spokes,
when the wheel was almost done (meaning spoke and nipple ends were flush)
and the rim was centered,
I noticed the square face of the nipple (where the tool engages) was starting to strip.
I loosened and removed the nipple, then replaced it.
With the nipple off, it's the same as if a spoke broke,
and that area develops significant lateral runout. The wheel center naturally shifts too.
When I tighten the replacement nipple back to the previous position,
the lateral runout, radial runout, and center should return to where they were.
In practice, it usually does pretty much exactly that, but
this time it was different. Even tightening until the spoke was pulling far out of the nipple,
the rim wouldn't return to center.
The resistance while tightening didn't increase "with each turn."
It felt like turning an infinite screw.
This is spoke stretching.
Using the stem screw analogy from earlier,
I'd entered the stretching phase when 1-2 tenths away from breaking.
Once this happens, "tightening the nipple = shortening the spoke" no longer works.
Once a spoke has stretched, it will never again
properly handle spoke tension perfectly.
In this case, replacing the spoke solved it.
This phenomenon has only happened twice with Competition spokes,
so getting stretched spokes to examine has been nearly impossible.
The image above shows the stretched spoke on the lower side.
I aligned the spoke heads and photographed the ends.
These were originally the same length.
What happened before is that this occurred inside the rim.
Comparing DT's round-section butted spokes:
Competition and Revolution.
Revolution has a 2.0mm and 1.8mm thread diameter model,
both with a 1.5mm butted section.
I recently noticed the 1.8mm Revolution has been discontinued.
The breaking risk must have been too high.
Competition has a 1.8mm butted section for the 2.0mm thread diameter model,
and a 1.6mm butted section for the 1.8mm model.
The length of the butted section also differs—with Revolution, almost everything except
the neck and threads is butted, making it extremely light.
Comparing the specific gravity to 2.0mm plain spokes:
2.0mm Competition is 85.6%,
2.0mm Revolution is 64.2%.
Since it's discontinued, I'm removing it from my spec sheet,
but the 1.8mm Revolution is 59.8%.
As for Revolution,
the "spoke stretching" phenomenon that's extremely rare with Competition
happens fairly frequently with Revolution.
While building, I say "ah, the wibbly-wobble showed up," but
tightening the nipple any further just converts to spoke stretching—
this becomes pretty common.
In other words, building a crisp wheel is very difficult.
Of course I can build them to a usable state, but
stretching often occurs well before reaching the rim's spoke tension limit.
This is where Sapim's CX-RAY comes in.
At 64.0% specific gravity, it can be thought of as a flattened version of the 2.0mm Revolution,
but CX-RAY is far less prone to stretching and I can build much crisper wheels.
For me, the CX-RAY's aero performance (wind-cutting) is frankly not that important.
What I appreciate is: a 64% specific gravity spoke that resists stretching better than Revolution,
and being flat means I can prevent nipple co-rotation while tightening.
Despite having nearly identical specific gravity, CX-RAY stretches less than Revolution,
which has little to do with aero sections—it comes down to
differences in tensile strength from spoke material and heat treatment.
Someone will probably say, "Then why not switch to Sapim for round-section butted spokes too?"
But that particular resistance to stretching isn't a property of all Sapim spokes,
only CX-RAY has it.
With round butted spokes, DT and Sapim are pretty much the same,
but DT has the advantage that I can stop by my distributor on the way to work in the morning.
Sakai and Osaka have lots of distributors, so it's very convenient.
This morning too (though by the time I'm writing this it's already yesterday's story)
I picked up one set of Dura-Ace and two sets of electronic Ultegra,
stuffing them into a large Ortlieb bag before coming in.
Getting back on topic, a spoke that's almost the same weight as 2.0mm Revolution
but with zero wibbly-wobble risk—
that's "CX-RAY from a builder's perspective."
It's a seemingly impossible but true story: the same-weight spoke having completely different
wheel crispness because of tensile strength differences.
Actually, I've been corresponding with a certain customer for a while now, and
based on the cross-sectional area ratio of CX-RAY and Revolution,
they had suggested that "crispness = resistance to wibbly-wobble"
should be about the same for both,
but I still needed to reply: "They're completely different when you build with them."
That's what all of the above is about. Sorry for the long post.
Of course, if a customer requests DT Revolution, I'll build with them.
I just don't use them for the standard Nomu Lab wheel specs or my personal wheels.
I'll talk about this from the builder's perspective rather than the rider's experience.
Before that.
There's an article I wrote about the threads on Ritchey's WCS stem
so please take a look. (→here)
That linked article was written by me a long time ago.
Among the 10 strength grades of JIS-standard screws,
the top 3 on the strong end are:
8.8 screws break at 80kg, and don't stretch beyond 64kg (80% of that).
10.9 screws break at 100kg, and don't stretch beyond 90kg (90% of that).
12.9 screws break at 120kg, and don't stretch beyond 108kg (90% of that).
That's what it means.
For example, on this Vision's TT bar,
the fixing screws on the arm pad bracket have a 10.9 marking.
This means they're not ordinary screws but "spec screws"
engineered to target strength properties within a very narrow range.
If you keep tightening a stem's screws beyond their limit, stretching occurs.
Eventually they'll break.
If you look closely at the threads of a stretched stem screw,
the pitch of the threads below the neck (the part that doesn't enter the threaded hole)
sometimes becomes uneven.
This preamble is long, but the point I'm making is
that both screws and spokes experience stretching.
I calculate spoke length using my own custom formula.
Many of the calculation formulas you find online have errors,
and special spoke patterns require correction values,
but I've never seen a formula that covers all of that.
My calculated spoke length is
the length where the spoke end and nipple end should be flush.
The images above show the actual state of a finished wheel build.
The other day, while building a wheel with DT Competition spokes,
when the wheel was almost done (meaning spoke and nipple ends were flush)
and the rim was centered,
I noticed the square face of the nipple (where the tool engages) was starting to strip.
I loosened and removed the nipple, then replaced it.
With the nipple off, it's the same as if a spoke broke,
and that area develops significant lateral runout. The wheel center naturally shifts too.
When I tighten the replacement nipple back to the previous position,
the lateral runout, radial runout, and center should return to where they were.
In practice, it usually does pretty much exactly that, but
this time it was different. Even tightening until the spoke was pulling far out of the nipple,
the rim wouldn't return to center.
The resistance while tightening didn't increase "with each turn."
It felt like turning an infinite screw.
This is spoke stretching.
Using the stem screw analogy from earlier,
I'd entered the stretching phase when 1-2 tenths away from breaking.
Once this happens, "tightening the nipple = shortening the spoke" no longer works.
Once a spoke has stretched, it will never again
properly handle spoke tension perfectly.
In this case, replacing the spoke solved it.
This phenomenon has only happened twice with Competition spokes,
so getting stretched spokes to examine has been nearly impossible.
The image above shows the stretched spoke on the lower side.
I aligned the spoke heads and photographed the ends.
These were originally the same length.
What happened before is that this occurred inside the rim.
Comparing DT's round-section butted spokes:
Competition and Revolution.
Revolution has a 2.0mm and 1.8mm thread diameter model,
both with a 1.5mm butted section.
I recently noticed the 1.8mm Revolution has been discontinued.
The breaking risk must have been too high.
Competition has a 1.8mm butted section for the 2.0mm thread diameter model,
and a 1.6mm butted section for the 1.8mm model.
The length of the butted section also differs—with Revolution, almost everything except
the neck and threads is butted, making it extremely light.
Comparing the specific gravity to 2.0mm plain spokes:
2.0mm Competition is 85.6%,
2.0mm Revolution is 64.2%.
Since it's discontinued, I'm removing it from my spec sheet,
but the 1.8mm Revolution is 59.8%.
As for Revolution,
the "spoke stretching" phenomenon that's extremely rare with Competition
happens fairly frequently with Revolution.
While building, I say "ah, the wibbly-wobble showed up," but
tightening the nipple any further just converts to spoke stretching—
this becomes pretty common.
In other words, building a crisp wheel is very difficult.
Of course I can build them to a usable state, but
stretching often occurs well before reaching the rim's spoke tension limit.
This is where Sapim's CX-RAY comes in.
At 64.0% specific gravity, it can be thought of as a flattened version of the 2.0mm Revolution,
but CX-RAY is far less prone to stretching and I can build much crisper wheels.
For me, the CX-RAY's aero performance (wind-cutting) is frankly not that important.
What I appreciate is: a 64% specific gravity spoke that resists stretching better than Revolution,
and being flat means I can prevent nipple co-rotation while tightening.
Despite having nearly identical specific gravity, CX-RAY stretches less than Revolution,
which has little to do with aero sections—it comes down to
differences in tensile strength from spoke material and heat treatment.
Someone will probably say, "Then why not switch to Sapim for round-section butted spokes too?"
But that particular resistance to stretching isn't a property of all Sapim spokes,
only CX-RAY has it.
With round butted spokes, DT and Sapim are pretty much the same,
but DT has the advantage that I can stop by my distributor on the way to work in the morning.
Sakai and Osaka have lots of distributors, so it's very convenient.
This morning too (though by the time I'm writing this it's already yesterday's story)
I picked up one set of Dura-Ace and two sets of electronic Ultegra,
stuffing them into a large Ortlieb bag before coming in.
Getting back on topic, a spoke that's almost the same weight as 2.0mm Revolution
but with zero wibbly-wobble risk—
that's "CX-RAY from a builder's perspective."
It's a seemingly impossible but true story: the same-weight spoke having completely different
wheel crispness because of tensile strength differences.
Actually, I've been corresponding with a certain customer for a while now, and
based on the cross-sectional area ratio of CX-RAY and Revolution,
they had suggested that "crispness = resistance to wibbly-wobble"
should be about the same for both,
but I still needed to reply: "They're completely different when you build with them."
That's what all of the above is about. Sorry for the long post.
Of course, if a customer requests DT Revolution, I'll build with them.
I just don't use them for the standard Nomu Lab wheel specs or my personal wheels.