Topic: 750K4 Bearing Replacement

[kmenzel]

I am replacing rhe ball bearings with the tapered type.  I bought the performance parts bearings, and it comes with one washer.  Has anyone used this brand, it comes in a green box and if so, did you use the spacer or not.  I have looked at the archives and other posts, but cannot find the answer.  Also, how did you drive the cones in, did you drop them into the freezer first?

[alfabeast]

That sounds like the kit I used on my 78k and I didn't need the spacer but  I have  heard conflicting information about fitting or not fitting the spacer, however you can check the clearances first:

1. Fit the outer races in the frame.
2. Hold the upper and lower inner races in the frame.
3. Measure length beteen inner bearing races.
4. Mark the measurement off on the triple tree shaft
5. Assemble lock nut, top tree and washer onto lower tree, with reference to the mark, and see how much thread you are left with for the top domed nut; too much thread you will need the spacer.

[alfabeast]

I forgot the second bit,

Rub a stone around the bearing surfaces on the triple tree shaft to remove any high spots/damge that might have resulted from removing the old bearings, then push the bearings on, if they are a bit tight then use a tube with an ID a little bigger than the triple tree shaft, they should only need a light tap.

[jotor]

I'm an empiricist so I'd probably just put it together without the spacer to see if it took up.  If not, then I'd put in the spacer.

[kmenzel]

Thats a killer looking cafe in your picture, thanks for the information.  When you pushed the bearing cones into the frame what kind of force did you use.  I just got the bike and all parts back from the painter and want to be carefull.  However, i better check to make sure the surfaces are without any bubbles or anythign that might obstruct the cones. 

What exactly does your cafe consist of, what year?

[alfabeast]

Stone the bore and then polish with some emery paper, grease the bore and get the bearing started in the hole by tapping with a soft mallet, get it in about 1/8" - 1/4" keeping it absolutely  level, if it's not too tight you can tap it alll the way in, if it's tight you can use a plate either end of the headstock and a length of studding as a draw bar, if the bearing starts to go in off level true it up by tapping on the high spot with a mallet and resume drawing down. I'm sure other people have their own way of doing it that works too.

thanks oldtoyhunter, it's a 69 sandcast I cafed it before the sandcast thing became the sandcast thing, in my defence it was a basket case and had none of the sandcast parts except for motor and frame, so I hope I'm forgiven

There are more pics on my site:
http://home.earthlink.net/~alfabike/

[Lumbee]

...hey Cris, I was look'n at the hard tail on u'r web site.  How did u do the paint job on the tank/fender?  Coat of red, then a coat of grey..then you sanded the edges with clear on top?

[kmenzel]

Are the races that are placed in the frame actually driven up into the framd about 1/4 inch on the bottem and maybe 1/8 inch on the top.  I was wondering if anyone had a trick to get them in past the frame, unfortunaley i destroyed the old races when i took them out, they were in bad shape. 

[dpen]

I use a block of wood across the cone for the initial seating e.g. bash wood with big hammer.
Wood is good because you can tap on different sides to straighten the cone as it's going in & you won't damage anything.
When the cone is flush with the steering head, use a drift (pin punch) to seat it.
The noise from the drift will tell you when the cone is fully seated. A hollow sound means that it's not seated, a solid sound is "seated".
If you're not sure of "the noise", tap the drift lightly.
If the cone isn't seated the drift will stay against the cone when you tap it.
A fully seated cone will cause the drift to "bounce" off the cone.
Freezing is not necessary.