A customer dropped off the front and rear wheels of a CADEX tubeless-ready rim.
Since they're sold as individual front and rear units, the customer changed the rim height between the front and rear wheels.
The wheels were purchased at a GIANT store, but after having Ichijo Cycle swap them out for oni bearings (premium performance bearings), both the front and rear hubs had play. After taking them back once or twice without getting it resolved, and after reading a similar article on this blog (→here)
...wait, that wasn't it (→here), the customer brought them to my shop.
First, the front wheel.
Placing the pad of my thumb on both ends of the hub and pushing alternately, there's a considerable amount of lateral play—I can reproduce the clicking sound 100% of the time. Even after removing the left and right locknuts and pressing directly on the hub axle, it's the same story.
↑Hub body left side (rotor mounting side) bearing.
At first glance it doesn't look like an oni bearing, but JTEKT bearings sometimes come with seals under the Koyo Seiko name depending on size, and you can see part of the Koyo imprint in the lower right of the second image.
The pipe inside the hub body that contacts the bearing inner race isn't actually making contact, and in the two images above, I've rotated and shifted the axis of that pipe to show it from different angles.
↑From the other side, it looks like this.
Either from prolonged use with play (though not years of heavy abuse), this smaller bearing on the opposite side is heavily damaged, and even re-pressing doesn't eliminate the hub axle play.
Apparently, oni bearings come with instructions for installation shops not to press them all the way in with full force, but incompetent shops that don't understand the degree of this instruction get nervous and install them loosely. This causes lateral play in the hub, and using it in that condition causes the bearing rotation to become rough very quickly—these examples are fairly common.
Rather than pressing both bearings simultaneously, I typically apply static load to just one side gradually, installing the end cap each time to check for play (the "re-pressing" method I mentioned earlier), but that didn't solve this problem either.
This small bearing on the right side had clearly excessive play between the inner and outer races, so I was confident a replacement was necessary. After getting the customer's okay, I extracted it. As a result, when I put my index finger in the inner race and rotated the outer race with my thumb, I could hear a grinding sound near my ear—the internals were that damaged. I then swapped it for a standard ball bearing of the same size (6802), which costs around 1,000 yen, and the hub's lateral play disappeared and rotation became smooth. The oni bearing installed by the incompetent shop was far worse than the standard ball bearing I swapped in.
What makes Ichijo Cycle even more foolish this time is that the customer brought it back again saying "Hey, something's still wrong,"essentially giving them another chance to either fix it properly or talk their way out of it, and they still didn't resolve it.
With the hub axle lateral play eliminated, I could now measure with a center gauge.
There was barely any runout, but there was center misalignment, so
I corrected it.
Next, the rear wheel.
Not as bad as the front, but there is lateral play in the hub axle.
Better than the front wheel, but it still makes clicking sounds from the play. After removing the freebody, I found no abnormalities in its bearings.
With the freebody removed (in "front-hub state"), there is play in the hub axle.
Here, re-pressing the left side (rotor mounting side) bearing eliminated the hub axle play.
But whether from age or use, there's some grittiness in the hub's rotation.
It wasn't damaged as severely as the front wheel's right bearing, but after consulting with the customer, I swapped the left 6802 for a standard ball bearing first. The grittiness still didn't completely disappear, so I also swapped the right 15267 for a standard ball bearing, and then finally the rotation became smooth.
↑The oni bearings that ended up with performance worse than standard ball bearings because of the installation shop's incompetence
The front wheel's right bearing made a grinding sound when I brought it near my ear and rotated it with my finger, but the rear hub's left and right bearings weren't damaged enough to make noise when spun individually.
CADEX originally comes with ceramic bearings, not oni bearings.
So maybe doing nothing would have been the optimal solution? I was about to say this to the customer, but they said the same thing first.
The oni bearings installed by the incompetent shop end up with durability and post-failure performance that fall far short of standard ball bearings in subsequent use.
If you own wheels with oni bearings, I strongly recommend pushing on both hub ends with your fingers to check for any clicking lateral play.
And unfortunately, shops that did this kind of botched work won't be able to re-press them to the proper position, and since the customer rode with lateral play for who knows how long※, the bearing rotation will become gritty in short order. Even if you ask them to replace it with a new one for free, no shop would agree to it.
※They're likely to make some excuse about how the customer is at fault for not noticing the lateral play and continuing to ride, or worse, blame the customer for not seeing through the fact that their shop—which can't even properly press in bearings and is a complete disaster—was incompetent when they brought their wheel in for the oni bearing work.
With the hub end play gone and a fixed reference point for the center gauge, I checked the wheel center.
Better than the front wheel, but the rim is offset toward the freewheel side.
There was more runout than the front wheel.
I corrected it while I was centering the wheel.
Honestly, when it comes to oni bearings, I think the cost-to-benefit ratio is extremely marginal.
On top of that, I don't have the guts to pay into the gacha of "this shop is certified for oni bearing installation, but maybe they're actually incompetent and can't install them properly." There's no way I'm gambling on that.
Since they're sold as individual front and rear units, the customer changed the rim height between the front and rear wheels.
The wheels were purchased at a GIANT store, but after having Ichijo Cycle swap them out for oni bearings (premium performance bearings), both the front and rear hubs had play. After taking them back once or twice without getting it resolved, and after reading a similar article on this blog (→here)
...wait, that wasn't it (→here), the customer brought them to my shop.
First, the front wheel.
Placing the pad of my thumb on both ends of the hub and pushing alternately, there's a considerable amount of lateral play—I can reproduce the clicking sound 100% of the time. Even after removing the left and right locknuts and pressing directly on the hub axle, it's the same story.
↑Hub body left side (rotor mounting side) bearing.
At first glance it doesn't look like an oni bearing, but JTEKT bearings sometimes come with seals under the Koyo Seiko name depending on size, and you can see part of the Koyo imprint in the lower right of the second image.
The pipe inside the hub body that contacts the bearing inner race isn't actually making contact, and in the two images above, I've rotated and shifted the axis of that pipe to show it from different angles.
↑From the other side, it looks like this.
Either from prolonged use with play (though not years of heavy abuse), this smaller bearing on the opposite side is heavily damaged, and even re-pressing doesn't eliminate the hub axle play.
Apparently, oni bearings come with instructions for installation shops not to press them all the way in with full force, but incompetent shops that don't understand the degree of this instruction get nervous and install them loosely. This causes lateral play in the hub, and using it in that condition causes the bearing rotation to become rough very quickly—these examples are fairly common.
Rather than pressing both bearings simultaneously, I typically apply static load to just one side gradually, installing the end cap each time to check for play (the "re-pressing" method I mentioned earlier), but that didn't solve this problem either.
This small bearing on the right side had clearly excessive play between the inner and outer races, so I was confident a replacement was necessary. After getting the customer's okay, I extracted it. As a result, when I put my index finger in the inner race and rotated the outer race with my thumb, I could hear a grinding sound near my ear—the internals were that damaged. I then swapped it for a standard ball bearing of the same size (6802), which costs around 1,000 yen, and the hub's lateral play disappeared and rotation became smooth. The oni bearing installed by the incompetent shop was far worse than the standard ball bearing I swapped in.
What makes Ichijo Cycle even more foolish this time is that the customer brought it back again saying "Hey, something's still wrong,"
With the hub axle lateral play eliminated, I could now measure with a center gauge.
There was barely any runout, but there was center misalignment, so
I corrected it.
Next, the rear wheel.
Not as bad as the front, but there is lateral play in the hub axle.
Better than the front wheel, but it still makes clicking sounds from the play. After removing the freebody, I found no abnormalities in its bearings.
With the freebody removed (in "front-hub state"), there is play in the hub axle.
Here, re-pressing the left side (rotor mounting side) bearing eliminated the hub axle play.
But whether from age or use, there's some grittiness in the hub's rotation.
It wasn't damaged as severely as the front wheel's right bearing, but after consulting with the customer, I swapped the left 6802 for a standard ball bearing first. The grittiness still didn't completely disappear, so I also swapped the right 15267 for a standard ball bearing, and then finally the rotation became smooth.
↑The oni bearings that ended up with performance worse than standard ball bearings because of the installation shop's incompetence
The front wheel's right bearing made a grinding sound when I brought it near my ear and rotated it with my finger, but the rear hub's left and right bearings weren't damaged enough to make noise when spun individually.
CADEX originally comes with ceramic bearings, not oni bearings.
So maybe doing nothing would have been the optimal solution? I was about to say this to the customer, but they said the same thing first.
The oni bearings installed by the incompetent shop end up with durability and post-failure performance that fall far short of standard ball bearings in subsequent use.
If you own wheels with oni bearings, I strongly recommend pushing on both hub ends with your fingers to check for any clicking lateral play.
And unfortunately, shops that did this kind of botched work won't be able to re-press them to the proper position, and since the customer rode with lateral play for who knows how long
※They're likely to make some excuse about how the customer is at fault for not noticing the lateral play and continuing to ride, or worse, blame the customer for not seeing through the fact that their shop—which can't even properly press in bearings and is a complete disaster—was incompetent when they brought their wheel in for the oni bearing work.
With the hub end play gone and a fixed reference point for the center gauge, I checked the wheel center.
Better than the front wheel, but the rim is offset toward the freewheel side.
There was more runout than the front wheel.
I corrected it while I was centering the wheel.
Honestly, when it comes to oni bearings, I think the cost-to-benefit ratio is extremely marginal.
On top of that, I don't have the guts to pay into the gacha of "this shop is certified for oni bearing installation, but maybe they're actually incompetent and can't install them properly." There's no way I'm gambling on that.