A customer brought in two pairs of Zonda wheels with C15 rims that aren't tubeless-compatible for inspection.
These wheels aren't the original owner's, so they wanted a thorough inspection.
Looking at the front and rear wheels with the cone adjustment nut side of the front hub considered as the left side, all the hub body stickers were facing the correct direction. If the rear hub's sticker were reversed, there'd be no way to fix it.
With C15 rims, you can just reverse the hub axle direction, but with C17 rims, the hub has distinct left and right orientations.
With C15 rim-era hubs, you can flip the left and right dust caps to switch the hub sides, but with C17 rim-era hubs, while the right dust cap has the same shape, the left dust cap—whose actual function as a dust cap was questionable—has been integrated into the hub body and no longer exists separately.
One pair of wheels had a relatively clean brake zone, but
the other pair shows some signs of use.
Not only that, but the sticker on the presumed right side had been worn away by the brake shoes. Since there's no wear mark on the outer edge of the rim, it seems the brake shoes were positioned quite far inward.
With a dual-pivot front brake, the Y-arm side uses the center pivot for the right brake shoe, and the C-arm side uses the shoulder pivot for the left brake shoe.
The Y-arm moves in a covering motion while the C-arm moves in a scooping motion, which causes the brake shoes to develop L-shaped or reverse L-shaped uneven wear over time. With the standard brake shoe positioning near the top of the brake zone, the reverse L-shaped wear of the C-arm shoe is commonly seen, so it's good to lower the C-arm side position slightly at some point during the shoe's life.
In the diagram above I've drawn it, but the L-shaped wear on the Y-arm side is rarely seen in practice because the center pivot doesn't change the contact between shoe and brake zone much as the shoe wears. This front wheel would have that happening on the right brake shoe, but the stepped Campagnolo aluminum rim brake zone that's only wide there, combined with the shoe positioning being too far inward, is simply causing L-shaped wear.
↑This is the side with the cone adjustment nut, which we're calling the left side,
and the left side had more extensive sticker wear. It's possible the shoe positioning was just too low, or they may have been using this as the right side.
Because of this, the customer wanted the sticker replaced on the front and rear wheels with the used brake zone, but since Campagnolo's warehouse only has C17 stickers in stock, we decided to just remove them instead.
Removing the sticker is reasonably difficult itself (the image above makes it look like it just peeled right off, but considerable effort went into making it peel that way), but the adhesive removal work afterward is genuinely time-consuming. It requires persistence more than technical skill, so even though the labor charge might seem inverted, it actually takes longer than the wheel truing work itself.
I'll start with the front and rear wheels that show brake zone wear. I overhauled the front wheel.
From now on, I check centering after hub overhaul. The rim had shifted slightly to the left side.
↑About this much
I trued the wheel and got the centering dialed in.
Next, the rear wheel.
As I mentioned earlier—"questionable whether it actually does its job"—the left dust cap was missing.
The freewheel body doesn't come off the hub axle easily, and there's light surface rust on the axle just below the outer bearing of the freewheel body.
The inner race of the outer freewheel body bearing is rusty and feels gritty when I rotate it, so I'll replace it.
The retainer bearing on the right side of the hub body is missing one ball bearing. It didn't fall into the hub body. I replaced it with a steel ball of the same size.
The freewheel pawl spring has a section that overlaps more than one full rotation that's out of round, so I'll replace it. If the spring deforms or breaks, you can end up in a really bad situation out on the road, but since it's an inexpensive part, I don't hesitate to replace it even for minor deformation.
↑This would be a reject in my assessment.
The provisional centering was spot-on. There was slight runout, but the center didn't shift after truing, and since I'd be posting nearly identical images, I didn't photograph the true final state.
Also, the anti-freewheel side image is highlighting that I replaced the left dust cap. With C17 Zonda, that dust cap area has become part of the hub body itself.
Next, the front wheel with the relatively clean brake zone.
Provisional centering was spot-on with virtually no runout.
This one's left dust cap was originally installed, but apparently had a crack in it. I wasn't deliberately trying to remove it, but it snapped and fell off during work. From this angle, you could arguably say it was doing its job as a dust cap.
Next, the rear wheel.
There's barely any surface rust on the axle side, and the freewheel body comes right off, but
the outer bearing is damaged, and
has more internal rust than the same spot on the rear wheel with the used brake zone (left side of the image).
The pawl spring doesn't need replacement.
↑From an angle it looks like this
This rear wheel also had spot-on provisional centering. It had some runout, so I expected centering shift after truing, but there wasn't any, so↑these are also the provisional centering images.
Done.
The customer also asked me to clean up the brake zones, but I'm out of rubber stones, so I'm calling it here for today.
These wheels aren't the original owner's, so they wanted a thorough inspection.
Looking at the front and rear wheels with the cone adjustment nut side of the front hub considered as the left side, all the hub body stickers were facing the correct direction. If the rear hub's sticker were reversed, there'd be no way to fix it.
With C15 rims, you can just reverse the hub axle direction, but with C17 rims, the hub has distinct left and right orientations.
With C15 rim-era hubs, you can flip the left and right dust caps to switch the hub sides, but with C17 rim-era hubs, while the right dust cap has the same shape, the left dust cap—whose actual function as a dust cap was questionable—has been integrated into the hub body and no longer exists separately.
One pair of wheels had a relatively clean brake zone, but
the other pair shows some signs of use.
Not only that, but the sticker on the presumed right side had been worn away by the brake shoes. Since there's no wear mark on the outer edge of the rim, it seems the brake shoes were positioned quite far inward.
With a dual-pivot front brake, the Y-arm side uses the center pivot for the right brake shoe, and the C-arm side uses the shoulder pivot for the left brake shoe.
The Y-arm moves in a covering motion while the C-arm moves in a scooping motion, which causes the brake shoes to develop L-shaped or reverse L-shaped uneven wear over time. With the standard brake shoe positioning near the top of the brake zone, the reverse L-shaped wear of the C-arm shoe is commonly seen, so it's good to lower the C-arm side position slightly at some point during the shoe's life.
In the diagram above I've drawn it, but the L-shaped wear on the Y-arm side is rarely seen in practice because the center pivot doesn't change the contact between shoe and brake zone much as the shoe wears. This front wheel would have that happening on the right brake shoe, but the stepped Campagnolo aluminum rim brake zone that's only wide there, combined with the shoe positioning being too far inward, is simply causing L-shaped wear.
↑This is the side with the cone adjustment nut, which we're calling the left side,
and the left side had more extensive sticker wear. It's possible the shoe positioning was just too low, or they may have been using this as the right side.
Because of this, the customer wanted the sticker replaced on the front and rear wheels with the used brake zone, but since Campagnolo's warehouse only has C17 stickers in stock, we decided to just remove them instead.
Removing the sticker is reasonably difficult itself (the image above makes it look like it just peeled right off, but considerable effort went into making it peel that way), but the adhesive removal work afterward is genuinely time-consuming. It requires persistence more than technical skill, so even though the labor charge might seem inverted, it actually takes longer than the wheel truing work itself.
I'll start with the front and rear wheels that show brake zone wear. I overhauled the front wheel.
From now on, I check centering after hub overhaul. The rim had shifted slightly to the left side.
↑About this much
I trued the wheel and got the centering dialed in.
Next, the rear wheel.
As I mentioned earlier—"questionable whether it actually does its job"—the left dust cap was missing.
The freewheel body doesn't come off the hub axle easily, and there's light surface rust on the axle just below the outer bearing of the freewheel body.
The inner race of the outer freewheel body bearing is rusty and feels gritty when I rotate it, so I'll replace it.
The retainer bearing on the right side of the hub body is missing one ball bearing. It didn't fall into the hub body. I replaced it with a steel ball of the same size.
The freewheel pawl spring has a section that overlaps more than one full rotation that's out of round, so I'll replace it. If the spring deforms or breaks, you can end up in a really bad situation out on the road, but since it's an inexpensive part, I don't hesitate to replace it even for minor deformation.
↑This would be a reject in my assessment.
The provisional centering was spot-on. There was slight runout, but the center didn't shift after truing, and since I'd be posting nearly identical images, I didn't photograph the true final state.
Also, the anti-freewheel side image is highlighting that I replaced the left dust cap. With C17 Zonda, that dust cap area has become part of the hub body itself.
Next, the front wheel with the relatively clean brake zone.
Provisional centering was spot-on with virtually no runout.
This one's left dust cap was originally installed, but apparently had a crack in it. I wasn't deliberately trying to remove it, but it snapped and fell off during work. From this angle, you could arguably say it was doing its job as a dust cap.
Next, the rear wheel.
There's barely any surface rust on the axle side, and the freewheel body comes right off, but
the outer bearing is damaged, and
has more internal rust than the same spot on the rear wheel with the used brake zone (left side of the image).
The pawl spring doesn't need replacement.
↑From an angle it looks like this
This rear wheel also had spot-on provisional centering. It had some runout, so I expected centering shift after truing, but there wasn't any, so↑these are also the provisional centering images.
Done.
The customer also asked me to clean up the brake zones, but I'm out of rubber stones, so I'm calling it here for today.