A customer brought in a Mavic
Ksyrium S 25 for service.
This is a rim brake model.
The model name laser-etched on the rim is
"KSYRIUM S 25" and includes rim depth information,
but the Japanese distributor calls it Ksyrium S,
and the disc version of this is Ksyrium S Disc.
Only the disc brake wheels have
a 30mm deep rim model,
and that one doesn't get the S designation—
it's just called Ksyrium 30 Disc.
Separately, there's also a Ksyrium SL model,
but since Mavic discontinued aluminum Zicral spokes,
unlike the same-named model from the past,
this one now comes with steel spokes.
In terms of specs and grade, this Ksyrium S
is pretty close to the old Ksyrium Elite,
but it differs in that the rim isn't offset
and the rear wheel is 24H instead of 20H.
The customer wants a new bike inspection.
Let's start with the front wheel.
↑These aren't the same image.
You can tell from the orientation of the hub body markings
that I photographed from both the left and right sides of the wheel.
What I'm getting at is that
instead of a QRM that grabs four of the six holes
on the left hub nut for bearing play adjustment,
both sides have fixed dropout ends.
It's the same structure you see when removing
the fixed dropout end on the left side of the Instant Drive 360
rear hub—
a washer is sandwiched between the snapring
mounted in the hub axle groove
and the bearing inner race
to absorb fine play.
The preliminary center was off by about a sheet of paper.
There was also lateral runout, and if you looked around,
you could find phases where the gap at the bottom of the upper image
was about twice as far (roughly two sheets of paper).
The customer requested "tension it as much as possible,"
and while this front wheel isn't a slack specimen,
it's true that we can still add more tension
within a range that won't affect wheel longevity.
While correcting runout,
I shifted the rim as much as possible.
Working from here with a tightening trend to center it—
From the original state,
there wasn't a single nipple trending loose—
all the nipples
were adjusted in a tightening direction,
to varying degrees.
Now for the rear wheel.
What Mavic calls Isopulse
isn't a term that refers only to radial lacing on the freewheel side.
The secret lies in the spoke path on the non-freewheel side.
With 20H (5 holes per side / 5 protrusions on the flange)
that worked out conveniently,
but going to 24H theoretically represents a step backward.
With aluminum spokes on the old Ksyrium wheels,
looking at spoke head positions,
the rear hub is effectively reverse high-low flanges,
but this wasn't because the freewheel side was made small—
rather, the non-freewheel side was deliberately made large for a reason.
Perhaps the thinking was "radial lacing doesn't change spoke path much
depending on flange diameter anyway,
so reverse high-low is fine," which is why
they don't use equal-diameter flanges on both sides.
This rear hub also could benefit from
a larger flange on the non-freewheel side,
but it's certain that going from 20H to 24H spokes
is the major factor in overall wheel performance improvement.
The freebody is Instant Drive 360,
but even in unused condition, the white proprietary grease
had already been pushed away from the face ratchet,
and it didn't feel like it was engaging properly.
↑This is the freebody side,
but the grease had been pushed away
on the back side of the ratchet ring as well.
Given that situation,
I applied a generous amount of Scope Cycling grease
(the standard red, not the Silent blue)
to both areas.
Unusually for a Mavic wheel,
the rim was shifted toward the freewheel side.
I corrected runout and tightened the freewheel side
in a way that amplified the center offset,
then achieved center by tightening the non-freewheel side.
This process isn't just a workflow I'm following for taking article photos—
it's genuinely easier to work
by splitting left and right.
Ksyrium S 25 for service.
This is a rim brake model.
The model name laser-etched on the rim is
"KSYRIUM S 25" and includes rim depth information,
but the Japanese distributor calls it Ksyrium S,
and the disc version of this is Ksyrium S Disc.
Only the disc brake wheels have
a 30mm deep rim model,
and that one doesn't get the S designation—
it's just called Ksyrium 30 Disc.
Separately, there's also a Ksyrium SL model,
but since Mavic discontinued aluminum Zicral spokes,
unlike the same-named model from the past,
this one now comes with steel spokes.
In terms of specs and grade, this Ksyrium S
is pretty close to the old Ksyrium Elite,
but it differs in that the rim isn't offset
and the rear wheel is 24H instead of 20H.
The customer wants a new bike inspection.
Let's start with the front wheel.
↑These aren't the same image.
You can tell from the orientation of the hub body markings
that I photographed from both the left and right sides of the wheel.
What I'm getting at is that
instead of a QRM that grabs four of the six holes
on the left hub nut for bearing play adjustment,
both sides have fixed dropout ends.
It's the same structure you see when removing
the fixed dropout end on the left side of the Instant Drive 360
rear hub—
a washer is sandwiched between the snapring
mounted in the hub axle groove
and the bearing inner race
to absorb fine play.
The preliminary center was off by about a sheet of paper.
There was also lateral runout, and if you looked around,
you could find phases where the gap at the bottom of the upper image
was about twice as far (roughly two sheets of paper).
The customer requested "tension it as much as possible,"
and while this front wheel isn't a slack specimen,
it's true that we can still add more tension
within a range that won't affect wheel longevity.
While correcting runout,
I shifted the rim as much as possible.
Working from here with a tightening trend to center it—
From the original state,
there wasn't a single nipple trending loose—
all the nipples
were adjusted in a tightening direction,
to varying degrees.
Now for the rear wheel.
What Mavic calls Isopulse
isn't a term that refers only to radial lacing on the freewheel side.
The secret lies in the spoke path on the non-freewheel side.
With 20H (5 holes per side / 5 protrusions on the flange)
that worked out conveniently,
but going to 24H theoretically represents a step backward.
With aluminum spokes on the old Ksyrium wheels,
looking at spoke head positions,
the rear hub is effectively reverse high-low flanges,
but this wasn't because the freewheel side was made small—
rather, the non-freewheel side was deliberately made large for a reason.
Perhaps the thinking was "radial lacing doesn't change spoke path much
depending on flange diameter anyway,
so reverse high-low is fine," which is why
they don't use equal-diameter flanges on both sides.
This rear hub also could benefit from
a larger flange on the non-freewheel side,
but it's certain that going from 20H to 24H spokes
is the major factor in overall wheel performance improvement.
The freebody is Instant Drive 360,
but even in unused condition, the white proprietary grease
had already been pushed away from the face ratchet,
and it didn't feel like it was engaging properly.
↑This is the freebody side,
but the grease had been pushed away
on the back side of the ratchet ring as well.
Given that situation,
I applied a generous amount of Scope Cycling grease
(the standard red, not the Silent blue)
to both areas.
Unusually for a Mavic wheel,
the rim was shifted toward the freewheel side.
I corrected runout and tightened the freewheel side
in a way that amplified the center offset,
then achieved center by tightening the non-freewheel side.
This process isn't just a workflow I'm following for taking article photos—
it's genuinely easier to work
by splitting left and right.