Axle Bearing Installation

I purchased a Birel Kid kart for my daughter that had been sitting for a couple years. I was changing the position of the gear carrier to make it acceptable for a 4cycle engine and had trouble with removing the axle bearing. The steps I took to remove it,removed the dowel screws. loosened the cassette, then I removed the Cassette, I added grease on the axle to try and slide i off, I ended up having to destroy the bearing to remove it. It’s strange because the Gear carrier came easily off. Now I am attempting to put a new Axle bearing and I can’t get it to move more then 2 inches. I have greased and sanded the axle, I now have it attached the hanger with the Cassette trying to hammer it from the other side and it won’t budge. Never had such trouble. Any tips?

Did you use a grease or a penetrating oil?

Sometimes the scoring on the axle that’s caused by the set screws prevents the bearings from sliding off easily. Between lube, sanding (if you can get in there) and brute force it should move.

I always loosen the set screws then spin the axle inside the bearing while holding the bearing from spinning with an Allen wrench in the loosened set screw. This essentially debuted the axle before trying to remove it.


I completely removed the set screws, I used penetrating oil then axle grease because I had that available. Really strange and frustrating especially since I did this to another kart I owned earlier this year.

If the axle’s bent, it will be VERY difficult to slide through the bearing - as in “several tons of force” difficult. You may need to knock it through, but before trying that, attempt to slide it out the other way as the bent end might not need to go through.

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I was about to write the same as Charles

I purchased an older kid kart for my daughter last year. I found out that that there could be one of two different axle sizes in it. 1 inch or 25 mm. Depending on the bearings used, a 25 mm bearing on a 1 inch axle will not move easily. FYI 1 inch is equal to 25.4 mm.

If you can get a 25mm bearing on a 1 inch axle …15 thou. interference!

There is no telling from the guy I bought it off of. I think he had zero wrenching experience before that. I had to hammer the old bearings off the axle and ended up replacing them. The new ones slid on easily in comparison.

I purchased a 30mm axle bearing because all the numbers on the other component indicate its 30mm. I hammered it on but a new issue developed on wheel hub I think it has to big of a key as it doesn’t fit the hub of the wheel. I am going to try and find a smaller key for it see if that fixes the problem.

A 30 mm.diameter axle would normally use 6mm square keys.Sometimes you need to file a bit off the top of the key to get an easy fit for the hub etc.