Unicornz0

Hello, the CK headset has the sealed bearings preinstalled in the headset cups. How can a homedale headset press be used to install this headset without damaging the race and bearings?
Does anyone have any Ideas on what can be used instead of the Chris King Headset Installation Adapter?

https://chrisking.com/tools/tls_headset

Thanks,
Uni

joejack951

You won't damage the bearings or race by pressing on the bearings to install the cups. The King adapters simply provide a better fit for the various available presses. You can accomplish the same thing by modifying some washers or wood blocks if it's even necessary. Ideally, you'll get a tight fit between your adapters, your forcing screws, and the headset so that there is no chance of the cups getting cokced sideways a bit.

HillRider

Use big enough washers that they press on the outer edges of the cups rather than on the bearings themselves. You might want to pad the washers with thin leather or wood to ease the load on the cup edges.

If you do press on the bearing cartridges, be certain to press only on the outer race, never on the inner race.

Unicornz0

Below are pictures of the headset press. Using it the way it's setup, I think will damage the inner bearing race. Just using the washers to press in the cups without the copper nipple may work, but might score the finish, and leave a visible score line on the cup outer edges. Please give specific directions if possible, so this headset doesn't get messed up. This is a last ditch effort to save a bike I enjoy. CK makes the only reducing headset that I'm aware of, the Devolution, 1 1/4" to 1 1/8". Tried to use the headset reducers previously, without much success. After about a month of XC riding they started to creak, and I don't think it's possible to separate the adapters from the headset cup once they have been installed into the head tube, to add more grease (who wants to do that every month). Further, I read that the headset adapters can cause the head tube to deform if the bike is ridden hard.

Thanks again for your help,
Uni

https://www.bikecommuters.com/2007/09...ools/#more-508

HillRider

Forget the copper "adapter" pieces and use the just largest washers to be sure you only press on the cup's outer edges. You can use the smaller washers outside the biggest one as stiffeners but the large washer should be the one resting on the cups. Pad the washers with leather or thin wood if possible.

I've installed several headsets this way and they've always worked fine.

dperreno

I think you're right, that press will push against the inside bearing race. I came up with my own press which pushes flat against the cups. I used 1/2" pipe as I wanted to use it to install a 1" headset, you may be able to go with 3/4" pipe for a 1-1/8" headset, I don't know.

dperreno

That big washer is just big enough to fit over the end of the threaded pipe, but not big enough to fit over the unthreaded portion. It measures 3/4" inside diameter. I'm pretty sure I bought everything at Home Depot.

Also, I was installing on a 60cm frame with a tall headtube. I thought I would need the pipe sections to be as long as possible. In fact, you can get away with shorter sections, I would recommend 2".

Unicornz0

Thanks very much, HillRider and Dperreno. Will use the new press and leather, or wood to protect the cup outer edges.
Uni

joejack951

Why would you think pressing on the inner race would be such a bad thing? When the headset is installed, the inner race is being pressed against. It takes some fairly big hits over potholes and such. Also, every press fit bearing I've ever installed gets pressed in by pushing on the inner race. Is there some design difference on the CK bearings that makes the inner race a bad spot to push?

HillRider

You're kidding right? Using the inner race of a cartridge bearing to drive it in or out is a sure-fire way to destroy the bearing. Quoting Lennard Zinn: "...it is best to use a either an old cartridge bearing or a similar sized disk of metal that acts on the outer bearing edge to tap the bearings into the hub."

If you look at a cartridge bearing headset, CK included, you will see that the crown race (actually just a support plate) trasnmits the bike's weight and shock loads to the outer race of the lower bearing and the inner race just centers the steerer and allows it to turn freely.

For further evidence, here is a direct quote from Chris King's headset installation sheet:

"Our press adapters help to correctly align the cups with the head tube and prevent damage
to the bearings by directing pressure only and evenly over the cups."

joejack951

I guess I'm envisioning the race setup on the bearings wrong. The bearings I'm used to installing are double row ball bearings for cars. Aside from having two rows of bearings, they are not much different from a cartridge bearing used in a bicycle hub. They all get pressed in and out (with significant force) using the inner race as the surface where the force is applied. Bicycle cartridge bearings are significantly smaller which might affect installation though the press in/out forces would also be that much lower.

In any cartridge bearing though, the outer race, balls, and inner race all see the same loads. The difference is in how the forces are applied. If pressing on the inner race applied a force in such a manner that it would push the bearing apart, then I could see how it would damage the bearing.

Here's a link to a cutaway of a double row ball bearing:
https://www.kilianbearings.com/double...bearings.shtml

HillRider

OK, I see the difference in our descriptions. If the bearing is a hard fit on the inner spindle or axle and a loose or mild press fit into the outer housing, you would drive it into place on the shaft by force on the inner race.

If, like most bike bearings, it's a hard fit in the outer housing and the axle/spindle is a slip fit (hubs and bottom brackets) then the driving force must be applied to the outer race.

We are both protecting the bearing the same way but for different applications.

Unicornz0

Thanks for the help everyone. Installation of the headset was problem free.
Uni