undercut steering stem

[GearHead]

Hi gang,
I just got the new steering stem bearings in today. (All Balls). The instruction say that I must make an undercut in the stem below the upper bearing for it to seat right on any suzuki pre- 79' . Mine is a 78 GS400. I definatly dont have the capability to make that cut and cant afford to screw it up. Any pointers on this? Anyone else had to go through this?
Thanks
GearHead

[IanFrancisco]

I have an All-balls kit in my VX800 and they just dropped in. A little effort was required to get the lower bearing onto the stem, but no torches, heat or cutting was needed, just some careful pounding. I would not install any kit that required any cutting on the steering stem. That is precision machine work and then you wouldn't be able to go back to stock bearings. These bearings are usually just standard issue bearings that you could actually find in any bearing shop, so I'm surprised that All-balls didn't do their homework on these kits. Guess they didn't think they'd sell enough of 'em to warrant the effort. I would return the kit and get bearings from a dealer or save money and take the old bearings to a business that sells nothing but bearings and let them match them up. Unless of course your original bearings were loose balls. I would certainly upgrade to tapered roller bearings in that case, cutting required or not.

[SqDancerLynn1]

The older GS bikes had a ball bearing setup. The cut is just to make sure the bearing seats all the way down Any machine shop should be able to do it. It may cost $40-50. The other option would be to get a later tripple tree assembly

[GearHead]

undercut bearings

HI all,
Thanks for the info. This bike definatly had the ball bearings. So I would like to upgrade. The later tripple tree assembly was another option I was considering. What later model tripple tree assemblies would fit this bike? Any easy way to tell? I was considering maby using a gsxr tree and forks. Then I could get rid of the spoked rims and run tubless tires and upgrade to hyd. disk brakes. Sound feasible on a 78 gs400?
Thanks again.
Gearhead.

(I'll try and get some pics posted of the build up.)

[AirCooledFour]

Me to

I was shocked to see the instructions to back cut steering stem on my all balls box as well... very strange... They didn't mention this before I purchased them!

HI all,
Thanks for the info. This bike definatly had the ball bearings. So I would like to upgrade. The later tripple tree assembly was another option I was considering. What later model tripple tree assemblies would fit this bike? Any easy way to tell? I was considering maby using a gsxr tree and forks. Then I could get rid of the spoked rims and run tubless tires and upgrade to hyd. disk brakes. Sound feasible on a 78 gs400?
Thanks again.
Gearhead.

(I'll try and get some pics posted of the build up.)

[AirCooledFour]

Brain fart

I was thinking this over, the whole cutting of the steering stem thing. Since the top tree is whats pressing down on the bearing to seat it in the top race, (via that funky nut) it shouldn't matter if you have a back cut on the stem below the threads (if its just to allow the stem to slide inside the bearing race with clearance)... RIGHT? Anybody have any thoughts?

[Nessism]

Sounds like a job for a file.

[Steve]

Looks like it's just making more room for the tapered bearings, which occupy a little more room on the stem.

.

[almarconi]

If allballs goes to the trouble of including the sketch and telling you that it needs to be done, why question it?

Since they market the product they must have a darn good reason for making the modification. Take the sketch and the part to a machine shop and let them modify it for you or use OEM bearings.

[AirCooledFour]

More Info

I posted the question asking to clarify "All Balls" steering stem modification to early Suzukis in order to fit there tapered bearings and this is the response I got:

"Hello Todd. This Kit fits many early Suzuki’s. On some early Suzuki’s there was a step on the top steering stem that prevented the tapered bearing from going down the stem far enough to tighten up. If your bike does not have a step on the steering stem or the step is below where it would interfere with the top bearing, disregard the instructions. If however your bike has an "interfering step" on the steering stem, you will need to modify your stem as per the instructions.
Stefan"

I don't believe I have this "interfering step" and will be test fitting them soon.
Comments? Pics of my stem are in my albums.

[makr]

I would try to keep as much of a radius that you can...metal failure loves sharp corners. It prolly is not in a place to fail, but yikes on where it is.

[Benstyle]

undercut?

Please let me know how this turns out.
I'm in the same situation, I've just received the bearings and the instructions. Someone has previously put tapered bearings on my 78 GS750 and they didn't make the undercut. I don't know if this was good or bad because by the time I received the bike, the bearings were well past it.

[AirCooledFour]

Ok

Please let me know how this turns out.
I'm in the same situation, I've just received the bearings and the instructions. Someone has previously put tapered bearings on my 78 GS750 and they didn't make the undercut. I don't know if this was good or bad because by the time I received the bike, the bearings were well past it.

I finished the install and had a friend turn the stem but it turned out to be unnessesary. AllBalls racing said only some models needed that mod and mine didn't. Try putting everything together and fit it up and you'll see if you need to make the mod.