STEERING STEM BEARING Replacement - Any Pointers?

[KXcam22]

SKF is an excellent quality german bearing, the best.  NTN is an excellent japanese bearing, likely just as good.  The Allballs bearings are definitely chinese.  Inferior to the first two - you can feel and see the difference in surface finish. I personally wouldn't run them as a high speed bearing (crank etc) but in a stearing head they would be fine, other than any seal issues.  The only advantage the Allballs have (other than price) is that they make kits the others do not, plus lots of metric oddball sizes that help when doing fork swaps or other custom work.  Bearing wholesalers are in your phone book yellow pages under "bearings".  I have BC bearing and KAMAN bearing nearby.  The races in the steering head pop out quite easily.  I doubt it would be possible to oval the head doing this.  My CBR900RR ones (alum frame) came out the same as steel framed ones. Just use a long punch with a good end (not rounded).  The stock KX bearings are good quality japanese bearings in std sizes. They can be matched up to SKF/NTN .  I did 4 steering heads last winter so I am up on the topic, 2 allballs conversions, 1 fork swap and 1 straight replacement. Hope this helps. Cam.

[Hick]

Pivot works has instructional videos on their website as well.  Has anyone used the pivot works kit?

[traileater]

I figured posting this in here wouldnt be a bad idea, along the same lines, how hard is it to press out a stem from a lower clamp? Im parting out an old rm250 and the buyer only needs the stem.

[Hick]

Did it on my K5 the other day was real easy with a press.  Did not take much time at all.

[traileater]

Ok, but how did you set it up to press it......piece of pipe over the stem maybe? I want to do it right without marring the clamp or stressing anything.

[KXcam22]

Stem down through the press, wood under the clamp to protect it and a suitable large socket on the end of the stem, then press away.  Some bikes are extremely tight. Cam.

[Hick]

Yep thats how i did it.  look at the vid on pivot works page good visual.

[TheGDog]

Many thanks to all who have contributed to this thread so far.

• I've finally got the Beast apart.
• I've removed the upper and lower bearing race cups from the steering stem tube
• I've remove the lower bearing cage and dust seal, by force snipping them with diagonals after they bent whilst being carefully hammered with punch toward the top of the stem.

This brings me to the point I'm at now. I'd like to post a pic and verify that what my finger is pointing at in the pic is the inner bearing race for the lower end of stem... and that this piece indeed needs to be removed? And once again re-verify the tips & tricks for how best to remove it.  I've re-read this thread in its entirety this evening in preparation for attacking this last part of the Steering Stem Bearing Replacement Project that is soooo long overdue.

On to the pic..

Another more close-up...


You'll notice the scratch marks under this lower bearing inner race. These make me question if using the edge of a center punch on the protruding lip of the bottom of the inner bearing race is maybe a bad idea?

How do you get this bastard off?

[Polar-Bus]

Option A is to use a pneumatic cutoff wheel to cut the inner race, it works, but gouges the crap out of your stem shaft.

Option B is much better and proffesional, but you need a shop press :

http://www.youtube.com/watch?v=2R92wxhc4_E

I have a shop press, if you want mail me your stem and i'll press the old and new bearing N/C as a favor.

Rich

[tobys 2 strokes]

heat the race up and it will fall off some times it will need a tap to get it going

[TheGDog]

Do I need to first freeze the whole thing, then immediately after taken out of freezer apply heat to that race?   Or should I just try heating the race only?

[don46]

not sure about the heat method of removal, race is steel and the stem is Aluminum, I would think the al will expand faster than the steel. I would press it out, granted you do have to be careful and support the clamp, but it can be done very effectively

[Polar-Bus]

I agree with don46, I tried once using a hefty amount oxy/acetylene heat to remove the lower stem bearing, and in this particular situation heat simply doesn't work.

[The Flyin Hawaiian]

I just heat the race up some with a trigger start torch and use a chisel, positioned against the lip of the race, and drive it off with a hammer. Very easy and has always worked for me. Then I use a piece of thin walled copper pipe thats the same diameter as the inner race of the bearing and press it on with my cheapo Harbor freight press.

[alward25]

This has always driven me crazy.  Now, I just press the stem off and press it back on and then press the bearing and seal on, remember the seal before the bearing.  Heat if you don't have access to a press.