Replace loose bearings with sealed/caged bearings on GT hub

[davegerard]

Hello,

I have not posted in forever on the site, good to be back. I have a GT hub that was not turning the wheel. Opened it up, it's loose bearings, a bunch of which are just crushed. Anyhow, I'd prefer to replace it with a set of sealed bearings, or caged bearings. Any ideas on how to do this? If there is a tutorial somewhere I'd appreciate it, mostly trying to figure out how to swap the cups.

 

[Starnger]

Hello,

I have not posted in forever on the site, good to be back. I have a GT hub that was not turning the wheel. Opened it up, it's loose bearings, a bunch of which are just crushed. Anyhow, I'd prefer to replace it with a set of sealed bearings, or caged bearings. Any ideas on how to do this? If there is a tutorial somewhere I'd appreciate it, mostly trying to figure out how to swap the cups.

For the caged bearings you need to just find a proper diameter of the bearing. I believe it is standardized, so just measure the cup and a cone together with the ball diameter and buy the one that fits. Keep in mind, if balls are crushed then there is quite a chance that both cup and cone surfaces are destroyed too, so it means it won't be long until your new bearings would fail.
Changing it for the sealed bearings is a better option, but it may be more difficult. Check the profile of the cup, most probably it won't have enough flat surface on the side to just put a sealed bearing in. It means you'd need or find the sealed bearing with the same profile, which is usually not really easy to do, or mill the cup and the cone to be flat and to accommodate the desired sealed bearing. Just measure all the spots and use a lathe or a milling machine to do that.

 

[horsefarmer]

Seems like a good resource.
https://bike.bikegremlin.com/2002/types-and-construction-of-bicycle-bearings/
When you say sealed do you mean caged?

 

[davegerard]

Thanks, I will look into that, may just be some trial and error. And I think caged just have the ring holding the bearings, the sealed ones are more like skateboard bearings.