A customer brought in the front and rear wheels of a Zonda for me to work on.
They wanted an inspection.
Let me start with the front wheel.
The hub rotation felt like the grease had washed out,
so I opened it up to check and found that was indeed the case.
I cleaned and reassembled it.
↑These are photos after truing, but
the temporary centering before disassembling the hub
and the temporary centering during hub assembly were both spot-on,
so I'm only showing the final state.
The opening image was shot from the side that is "not" the hub bearing cone adjustment nut,
but it appears this wheel was installed on the front fork treating that side as the right.
That's because in the image above, on the brake zone of what we're calling the right side,
there's an area where the brake shoe isn't contacting the inner rim edge, but
on the brake zone of the opposite side,
it's hitting in quite an extreme way.
This wheel wasn't owned by the current customer initially—
since this is the first inspection we did at the shop after they acquired it
and before using it, the customer hasn't been operating it in this condition long-term.
With a dual-pivot front brake,
the left side becomes the C-arm side, creating a scooping arc.
This rim is a Zonda with a C15 rim before the wider rim conversion to C17,
so if this were swapped from a wheel with a wider rim
and the brake settings remained the same,
it's possible that only the lower end of the brake shoe
would contact near the upper end of the rim.
Now for the rear wheel.
There was a wear mark on one side of the rim showing
"the brake shoe was at this height when metal debris was lodged here,"
but since there's no step perceptible when I scrape it with a fingernail,
there's no issue.
The temporary centering before disassembling the hub was spot-on.
With a steel freewheel body,
the cavity closer to the hub shell is large, so
when usage history is shallow, the original grease
accumulates cleanly like this.
Unlike the front wheel, the rotation didn't have a rasping feeling,
but various things seemed unreliable, so
I overhauled the hub.
I'm cleaning all the parts.
The previous owner
seemed to have done a poor job with brake and derailleur adjustments.
Regarding brakes, based on
the wear marks on the front wheel and debris lodged in the brake shoes,
the derailleur adjustment being poor was evident from
the marks on the hub flange where the chain had been dropped,
though there was no spoke damage.
before
after
The temporary centering that was spot-on before taking apart the hub
is now severely off, with the rim shifted toward the freewheel side (right side).
It's not that the right end nut was loose from the initial temporary centering.
During hub disassembly and reassembly,
centering deviation can occur depending on how much the
split-seating centering wedge washer bites into
the left cup on the hub shell,
but in that case it's at most a paper-thickness difference.
It doesn't shift this much.
The likely cause is that since there was a big runout on the anti-freewheel side,
I happened to take the initial temporary centering near that phase.
Here's the temporary centering at the completion of the initial truing pass.
When the rim was shifted toward the freewheel side
and I trued with emphasis on tightening the freewheel-side nipples,
the amount of centering deviation should have increased,
but actually it decreased slightly.
This suggests that correcting the large lateral runout on the anti-freewheel side
had a significant beneficial effect on wheel center improvement.
The initial temporary centering changes depending on
which phase the centering gauge is applied at,
but after truing, the result is the same regardless of where you measure.
It's not quite as gratifying as a left-right balanced rear wheel,
but I approached centering by interpreting the ability to tighten
the anti-freewheel side as a "tightening bonus."
They wanted an inspection.
Let me start with the front wheel.
The hub rotation felt like the grease had washed out,
so I opened it up to check and found that was indeed the case.
I cleaned and reassembled it.
↑These are photos after truing, but
the temporary centering before disassembling the hub
and the temporary centering during hub assembly were both spot-on,
so I'm only showing the final state.
The opening image was shot from the side that is "not" the hub bearing cone adjustment nut,
but it appears this wheel was installed on the front fork treating that side as the right.
That's because in the image above, on the brake zone of what we're calling the right side,
there's an area where the brake shoe isn't contacting the inner rim edge, but
on the brake zone of the opposite side,
it's hitting in quite an extreme way.
This wheel wasn't owned by the current customer initially—
since this is the first inspection we did at the shop after they acquired it
and before using it, the customer hasn't been operating it in this condition long-term.
With a dual-pivot front brake,
the left side becomes the C-arm side, creating a scooping arc.
This rim is a Zonda with a C15 rim before the wider rim conversion to C17,
so if this were swapped from a wheel with a wider rim
and the brake settings remained the same,
it's possible that only the lower end of the brake shoe
would contact near the upper end of the rim.
Now for the rear wheel.
There was a wear mark on one side of the rim showing
"the brake shoe was at this height when metal debris was lodged here,"
but since there's no step perceptible when I scrape it with a fingernail,
there's no issue.
The temporary centering before disassembling the hub was spot-on.
With a steel freewheel body,
the cavity closer to the hub shell is large, so
when usage history is shallow, the original grease
accumulates cleanly like this.
Unlike the front wheel, the rotation didn't have a rasping feeling,
but various things seemed unreliable, so
I overhauled the hub.
I'm cleaning all the parts.
The previous owner
seemed to have done a poor job with brake and derailleur adjustments.
Regarding brakes, based on
the wear marks on the front wheel and debris lodged in the brake shoes,
the derailleur adjustment being poor was evident from
the marks on the hub flange where the chain had been dropped,
though there was no spoke damage.
before
after
The temporary centering that was spot-on before taking apart the hub
is now severely off, with the rim shifted toward the freewheel side (right side).
It's not that the right end nut was loose from the initial temporary centering.
During hub disassembly and reassembly,
centering deviation can occur depending on how much the
split-seating centering wedge washer bites into
the left cup on the hub shell,
but in that case it's at most a paper-thickness difference.
It doesn't shift this much.
The likely cause is that since there was a big runout on the anti-freewheel side,
I happened to take the initial temporary centering near that phase.
Here's the temporary centering at the completion of the initial truing pass.
When the rim was shifted toward the freewheel side
and I trued with emphasis on tightening the freewheel-side nipples,
the amount of centering deviation should have increased,
but actually it decreased slightly.
This suggests that correcting the large lateral runout on the anti-freewheel side
had a significant beneficial effect on wheel center improvement.
The initial temporary centering changes depending on
which phase the centering gauge is applied at,
but after truing, the result is the same regardless of where you measure.
It's not quite as gratifying as a left-right balanced rear wheel,
but I approached centering by interpreting the ability to tighten
the anti-freewheel side as a "tightening bonus."