I received the front and rear wheels of a Bora 35 from a customer.
They wanted me to replace the hub axles.
Let me start with the front wheel.
It's a tubular rim, but the wide rim version.
Someone knowledgeable would notice from the side view that it's not a narrow rim because the nipples aren't internal.
There was something stuck to the hub body.
The 14mm gripping surface of the front hub axle showed no major wear marks, so I didn't feel replacement was necessary.
However, the right end loosened first, so it was definitely a candidate for catastrophic failure with a new axle.
I loosened the left end.
While keeping track of which was right and which was left, I disassembled the parts, cleaned them, and then applied the right end to the hub axle with a set screw.
I reassembled the parts and corrected the slight run-out that was present. There was no center offset to begin with.
I think there was some basis for our shop's inspection history from earlier, but I shouldn't worry about it.
Next, the rear wheel.
Ah, so the bad hub axle was this one.
The hex hole at the end of the rear hub axle has cracked from corrosion.
The right end nut was also rusted and swollen.
The left end isn't absolutely requiring replacement, but the customer requested it.
While the rust on the splined section is manageable, there's white corrosion forming on the part that contacts the frame, so it's not unreasonable to judge it as a crack candidate.
Removing this right end was extremely difficult.
I extracted the freewheel body-equipped hub axle from the hub shell, clamped it in a vise with an axle cone wrench attached, and finally got it off by turning it with a thick standard wrench rather than a thin hub wrench on the 17mm.
The bearings inside the freewheel body, particularly the outer bearing, are damaged, with corrosion marks between the inner race and the hub axle.
The hub axle shows almost no marks from the axle cone wrench and could be reused, but I decided to replace it at the customer's request.
This rear hub axle comes in two types. The bearing adjustment nut has a fine thread pitch on the new model and a coarse pitch on the older model. Of course, the bearing adjustment nut is specific to each hub axle type. All other parts are the same.
The part numbers are BO100 for the old type and BO101 for the new type. FH stands for freewheel body, and BO indicates that this part originally came from Bora wheels.
Even if the wrong parts are ordered, some crappy shops claim the customer should buy them back due to poor explanation—I'm not making this up, there really are such shops (→here). I'm writing this down just to be sure we avoid such accidents. I hope that crappy shop goes out of business. Oh wait, it already did. Ha ha.
I keep the end parts for the hub axles in stock for both front and rear.
The bearing position relative to the hub axle. The bearing size is the same as the standard 6902, but it used to have one side with a blue seal and the other side open before the hub axle had the step-down (the notch visible in the photo). If the freewheel body was for Campagnolo, grease could be injected into the bearings with a grease gun. The remnant of that design—having one side unsealed—continued for about 10 years, but now both sides have seals: one blue and one black. Due to the legacy of the open-side design, the blue seal is pressed in facing outward on both sides of the freewheel body (as shown in the image above).
But when I write this, someone will definitely say "My wheel's freewheel body has a black seal showing on the outside!" So let me add a note: due to the whim of the manufacturer, some of these freewheel bodies were shipped with black seals on both sides. So if your wheel is in factory condition and shows a black seal from the outside, that's not abnormal. That bearing should have a black seal on the inside as well.
The detent spring on the freewheel body needed replacement, so I replaced it. If slightly over one complete turn doesn't lie flat evenly, replacement is necessary.
↑Compared to a new one, it looks like this
I removed the bearings from the freewheel body and cleaned them. There are secondary corrosion marks where the outer bearing's outer race contacted the hub.
I reassembled the parts.
The work on the truing stand was minimal—I just corrected the slight run-out that was there.
They wanted me to replace the hub axles.
Let me start with the front wheel.
It's a tubular rim, but the wide rim version.
Someone knowledgeable would notice from the side view that it's not a narrow rim because the nipples aren't internal.
There was something stuck to the hub body.
The 14mm gripping surface of the front hub axle showed no major wear marks, so I didn't feel replacement was necessary.
However, the right end loosened first, so it was definitely a candidate for catastrophic failure with a new axle.
I loosened the left end.
While keeping track of which was right and which was left, I disassembled the parts, cleaned them, and then applied the right end to the hub axle with a set screw.
I reassembled the parts and corrected the slight run-out that was present. There was no center offset to begin with.
Next, the rear wheel.
Ah, so the bad hub axle was this one.
The hex hole at the end of the rear hub axle has cracked from corrosion.
The right end nut was also rusted and swollen.
The left end isn't absolutely requiring replacement, but the customer requested it.
While the rust on the splined section is manageable, there's white corrosion forming on the part that contacts the frame, so it's not unreasonable to judge it as a crack candidate.
Removing this right end was extremely difficult.
I extracted the freewheel body-equipped hub axle from the hub shell, clamped it in a vise with an axle cone wrench attached, and finally got it off by turning it with a thick standard wrench rather than a thin hub wrench on the 17mm.
The bearings inside the freewheel body, particularly the outer bearing, are damaged, with corrosion marks between the inner race and the hub axle.
The hub axle shows almost no marks from the axle cone wrench and could be reused, but I decided to replace it at the customer's request.
This rear hub axle comes in two types. The bearing adjustment nut has a fine thread pitch on the new model and a coarse pitch on the older model. Of course, the bearing adjustment nut is specific to each hub axle type. All other parts are the same.
The part numbers are BO100 for the old type and BO101 for the new type. FH stands for freewheel body, and BO indicates that this part originally came from Bora wheels.
Even if the wrong parts are ordered, some crappy shops claim the customer should buy them back due to poor explanation—I'm not making this up, there really are such shops (→here). I'm writing this down just to be sure we avoid such accidents. I hope that crappy shop goes out of business. Oh wait, it already did. Ha ha.
I keep the end parts for the hub axles in stock for both front and rear.
The bearing position relative to the hub axle. The bearing size is the same as the standard 6902, but it used to have one side with a blue seal and the other side open before the hub axle had the step-down (the notch visible in the photo). If the freewheel body was for Campagnolo, grease could be injected into the bearings with a grease gun. The remnant of that design—having one side unsealed—continued for about 10 years, but now both sides have seals: one blue and one black. Due to the legacy of the open-side design, the blue seal is pressed in facing outward on both sides of the freewheel body (as shown in the image above).
But when I write this, someone will definitely say "My wheel's freewheel body has a black seal showing on the outside!" So let me add a note: due to the whim of the manufacturer, some of these freewheel bodies were shipped with black seals on both sides. So if your wheel is in factory condition and shows a black seal from the outside, that's not abnormal. That bearing should have a black seal on the inside as well.
The detent spring on the freewheel body needed replacement, so I replaced it. If slightly over one complete turn doesn't lie flat evenly, replacement is necessary.
↑Compared to a new one, it looks like this
I removed the bearings from the freewheel body and cleaned them. There are secondary corrosion marks where the outer bearing's outer race contacted the hub.
I reassembled the parts.
The work on the truing stand was minimal—I just corrected the slight run-out that was there.