Figure I should ask about this before putting it all back together. I know cups are meant to be fixed and are not replaceable. Wouldn’t the axle hold everything in place if preloaded correctly so it would just rotate but not back out or anything? Rear wheel off a 1963 Schwinn Continental, says Atom on it.
Cup able to rotate. Safety problem or just a bit annoying?
byu/Few-Supermarket1305 inbikewrench
by Few-Supermarket1305
6 Comments
Yes i’m aware the spokes are a bit munted.
One your wheel is tensioned the cup should stay in place
if you need to keep using this wheel I would suggest popping it out and putting some JB weld behind it and then using an axle with washers or soemthing to hold it in place and parallel while it cures…
Other than that I wouldn’t run something where the cup can rotate, if it does it means your bearing surface becomes the hub aluminum and that’s .. undesireable..
Cups separating from the hubs are a very old problem. The cup is in place with an interference (press) fit, it is easy for manufacturing to see a drift and not have adequate pressure to hold in the cup correctly. In addition, the materials use on lower end bikes can be horrible. My guess is that your bike is so old that thermal cycling with two materials of slightly different expansions has helped it worked lose over age.
These are found in two ways:
1. Like you when you disassemble
2. Rider hearing a weird noise as they ride, and find a distorted cup.
The press is on the side of the hub body, and the frictional grip by tensioning the bearing will not keep the cup from moving. Over time, the cup will deform due to movement, and you’ll get worse deformation and eventual failure.
The key is “eventually.” The abuse that a cup and cone on a bicycle can take is amazing. I would venture if the cup is simply rotating, you may be able to get thousands of miles out of it if you assemble it and it seems to rotate smoothly without sound and small movement. I can’t recall ever hearing of a catastrophic failure, and with all the junk on the market, I would think that this happens a lot. If you do seal it back up and ride it, I would check it at 100, 500, and 1000 miles by hand to see if you can feel movement from cup deformation.
It would be fun to hear your results, as I don’t remember anybody doing this experiment.
I would run it. Maybe not on a tour though. You’ll just have to replace it eventually
Sure this isn’t great, but I wonder if in reality the cup stays put while the bearings do their thing, assuming the preload on the bearings via the cones on the axle would result in the cup being held tight enough against the hub, and assuming the bearings have an order of magnitude lower rolling resistance than the cup to hub.