A customer brought in a
Bora Ultra 35 tubular rim model. They wanted an inspection, but separately from that,
they also wanted the rim cement bed removed. Essentially, they want to transition to tubular tape,
and the person who used rim cement was not the current owner.
Continental Competition tires are mounted,
and the rim cement had completely evaporated and become rock-hard. The tire tread shows almost no wear,
and if continuing with rim cement, it could still be used.
I removed the front tire. This is the thickest bed area, but even so,
there's no spot where the rim surface is visible. Yeah, this is impossible! I thought I'd just teach the customer about the acetone I use and where to get it,
and call it done. But even pushing myself hard,
complete removal with acetone would be such a pain
that it's not impossible, but practically impossible. However, there's a method that doesn't rely so much on willpower
that serves as a meal ticket code, so
I decided to give it a try.
Here's the front wheel with the bed removed. Even knowing the method well, it's a lot of work,
and even for me, I could do it at the shop but not at home. Regarding acetone, on rims like Lightweight or older Colima
where the rim sides have cosmetic paint, or
stickers without a clear protective layer,
the color will disappear if acetone touches them. In the case of this Bola, the cosmetic sticker on the rim is under a clear coat,
so I don't have to worry about acetone dripping on the rim side
(and don't need to protect it), which was also a reason I decided to tackle it.
I didn't take progress photos during the front wheel work, but
the rear wheel looked like this around the valve hole before starting.
The thickest bed area looks like this. It's slightly thinner than the front wheel,
but I don't sense any particular intention to make it thinner for the rear wheel.
I soaked a fresh rag in acetone
and transferred the rim cement to the rag—the image above shows
the side that was facing the rim.
This is the outside of the same spot—the marks where
I rubbed with three fingers pressed in. Where the rag has acetone on it,
the power to remove rim cement becomes quite weak. The loss of fiber nap on the cloth
might be related to this as well. Also, acetone evaporates quickly, and when it dries,
the part with rim cement becomes stiff and hardened.
The rim cement remaining in the tire bead groove—
removing this requires more acetone
relative to the amount of cement compared to other areas. If you remove it to the level shown above,
it's sufficient for transitioning to tape.
Here's what it looks like when completely removed from a different spot.
This is what the rag looked like then.
I've nearly completely removed the cement from the rear wheel too.
The rags are fine, but the amount of acetone I used is crazy.
The freewheel body had grease applied in a strange way,
so I decided to remove and clean it. The hub bearing preload adjustment had play in it,
and while they're particular about relatively unimportant details,
more fundamental aspects aren't right—it really feels like amateur work.
The pawl spring showed no deformation.
Only the rear wheel was missing the valve bush, so
I installed the third generation, which is the current model. This part isn't just "nice to have"—
it's an absolutely necessary functional component.
The front wheel had the second generation. Of the first through third generation versions, only the second generation
can come off even with the valve in place, but
the front wheel's valve bush had rim cement dripping down
from the outer edge of the valve hole, bonding it solid,
and I couldn't remove it by hand. I don't think this was intentional. That would make it strange for the rear wheel to be missing one.
Finally getting to the actual inspection work. The rim had shifted toward the freewheel side, but
it's reasonable to attribute this to age. There was faint lateral runout in two spots,
but only noticeable on the truing stand—
the amount is so small you probably couldn't detect it with the bike in use.
I did truing and centering work.
Now for the front wheel.
For a Bola off-the-shelf wheel, this one's fairly off-center. It likely wasn't pulled off-center during truing work—
it was probably like this from the start. There was almost no lateral runout.
I centered it.
Bora Ultra 35 tubular rim model. They wanted an inspection, but separately from that,
they also wanted the rim cement bed removed. Essentially, they want to transition to tubular tape,
and the person who used rim cement was not the current owner.
Continental Competition tires are mounted,
and the rim cement had completely evaporated and become rock-hard. The tire tread shows almost no wear,
and if continuing with rim cement, it could still be used.
I removed the front tire. This is the thickest bed area, but even so,
there's no spot where the rim surface is visible. Yeah, this is impossible! I thought I'd just teach the customer about the acetone I use and where to get it,
and call it done. But even pushing myself hard,
complete removal with acetone would be such a pain
that it's not impossible, but practically impossible. However, there's a method that doesn't rely so much on willpower
that serves as a meal ticket code, so
I decided to give it a try.
Here's the front wheel with the bed removed. Even knowing the method well, it's a lot of work,
and even for me, I could do it at the shop but not at home. Regarding acetone, on rims like Lightweight or older Colima
where the rim sides have cosmetic paint, or
stickers without a clear protective layer,
the color will disappear if acetone touches them. In the case of this Bola, the cosmetic sticker on the rim is under a clear coat,
so I don't have to worry about acetone dripping on the rim side
(and don't need to protect it), which was also a reason I decided to tackle it.
I didn't take progress photos during the front wheel work, but
the rear wheel looked like this around the valve hole before starting.
The thickest bed area looks like this. It's slightly thinner than the front wheel,
but I don't sense any particular intention to make it thinner for the rear wheel.
I soaked a fresh rag in acetone
and transferred the rim cement to the rag—the image above shows
the side that was facing the rim.
This is the outside of the same spot—the marks where
I rubbed with three fingers pressed in. Where the rag has acetone on it,
the power to remove rim cement becomes quite weak. The loss of fiber nap on the cloth
might be related to this as well. Also, acetone evaporates quickly, and when it dries,
the part with rim cement becomes stiff and hardened.
The rim cement remaining in the tire bead groove—
removing this requires more acetone
relative to the amount of cement compared to other areas. If you remove it to the level shown above,
it's sufficient for transitioning to tape.
Here's what it looks like when completely removed from a different spot.
This is what the rag looked like then.
I've nearly completely removed the cement from the rear wheel too.
The rags are fine, but the amount of acetone I used is crazy.
The freewheel body had grease applied in a strange way,
so I decided to remove and clean it. The hub bearing preload adjustment had play in it,
and while they're particular about relatively unimportant details,
more fundamental aspects aren't right—it really feels like amateur work.
The pawl spring showed no deformation.
Only the rear wheel was missing the valve bush, so
I installed the third generation, which is the current model. This part isn't just "nice to have"—
it's an absolutely necessary functional component.
The front wheel had the second generation. Of the first through third generation versions, only the second generation
can come off even with the valve in place, but
the front wheel's valve bush had rim cement dripping down
from the outer edge of the valve hole, bonding it solid,
and I couldn't remove it by hand. I don't think this was intentional. That would make it strange for the rear wheel to be missing one.
Finally getting to the actual inspection work. The rim had shifted toward the freewheel side, but
it's reasonable to attribute this to age. There was faint lateral runout in two spots,
but only noticeable on the truing stand—
the amount is so small you probably couldn't detect it with the bike in use.
I did truing and centering work.
Now for the front wheel.
For a Bola off-the-shelf wheel, this one's fairly off-center. It likely wasn't pulled off-center during truing work—
it was probably like this from the start. There was almost no lateral runout.
I centered it.