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Sunday, November 17, 2013

CT70 All Balls Neck Bearings

Back to work on the Trail 70.

I need to start with the three or four or six handed job of swapping neck bearings. Columbus is always willing to help and I really appreciate him for that. After the neck bearings are in, I can work on the rest of it by myself and with the help of a seven year old.

Start with a set of All Ball Racing bearings. These are timken-style instead of loose balls like the stockers.

Two different bearings. The inner diameters are different and the outer races are different, too. The two dust seals(stacked in this picture) appear to be identical.

Here's the story on the different ID's. The big one is the bottom and smaller is the top. These are press fit and this picture is for planning and mock-up only.

The trees were powdercoated. My guy masked the top threads, but didn't mask the bearing journals. I don't like that extra thickness on there and I think the PC may gall up and make a mess. So I masked the neck with duct tape and went to scrapping.

That's most of it off of where I don't want it. Next time tell the PC guy to mask those.

A little emery cloth to clean up the rest.

Pack the bearings.

Put a seal on and lower the bottom bearing into place.

The stem is about 0.900 inch so a 1 inch ID pipe is perfect.

A couple of solid hits, but not all the way yet.

Align the dust seal before you fully seat the bearing.


Now drive the old races(top and bottom) out of the frame neck with a brass punch and big hammer.

Some cleaning out of PC is needed here, too.

This is the six handed part. Columbus has the bearing race, driver, and hammer. I held the frame with the neck square on the bench. Columbus' wife took the pictures for the blog. Verify that you have the top race or the bottom accordingly.

Drive the top race until it bottoms out.

Flip the frame and do the other one.

Pull the masking off the stem threads.

Put the stem through the frame and place the top bearing in place.

"Press" the top bearing into place with the steering stem nut and a hook spanner wrench.

Once the bearing is seated, take the nut off and put the other dust seal in place.

Put everything back together and check it out. It may need re-adjusting after a few miles, but at least I can start building the rest of the bike.


  1. Nice write up....always enjoy your posts over on lillhonda, and have visited your page blog a couple times now. thanks for putting this all "out there" :)

    1. The top bearing and seer are too high on mine. The top plate doesn't sit down far enough.