Play in forks after KX mod doesn't go away

[MXOldtimer]

If you need some shim stock let me know. I think I still have my left over laying around somewhere in the shop.

.

[canyncarvr]

With the steering together:

With NO mass attached (bars off, not in the way, front wheel off)) you should feel NO 'notch' hesitation or bind within the full movement of the stem. It is possible to NOT feel impending bearing failure turning the bars back and forth with the wheel on. It will feel smooth..but it's not.

With the steering apart:

The bearing (the tapered roller part) won't be 'good' if the outer race is bad...and the bearing won't be BAD if the outer race is good.

So..look at the outer race.

If you see marks where the tapered rollers have been moving (trying to) that's not good. If you see the silvery finish of the race gone with a brass-looking color showing through..that isn't good either.

Most of the stress is on the lower bearing and that will show up on the TOP (forward) part of the outer race. Just look at it.

If the wear/damage noted above is slight (you can't feel it with your finger), you can 'cheat' some by removing the used race and reinstalling it in a different orientation to the frame..say 90º out from what it was.

A tapered roller would prefer to spin..like a wheel bearing. Simply moving back and forth over a small arc makes its life hard for obvious reasons. The load/shock of impact is not distributed too well.

A tapered roller is a whole lot better than the balls/cups that bikes used to have for bearings in the stem area!

Doesn't mean their life isn't tough!

What piece on a dirtbike doesn't have a hard life!!!

I'm glad I'm not a tire................

[it175]

I concure with C.C.

[IdahoCharley]

I'm glad I'm not a tire................

I feel like I'm been a tire.

Been stomped on, ran over, mistreated, under rated, abused, run low, trashed, replaced, run into obstacles, over-inflated, bruised, torn apart to the core, stabbed, etc. Its LIFE and I know you have been there also!!

[canyncarvr]

indeed!

Life may well be tire-like at times...but you know what they say....

...the alternative ain't all peaches and cream either!

Well, not that I know about that one way t'other.......


Is this KX frontend fixed yet??

[wanaride]

Not yet. I need to disassemble the front end and check the lower bearing race to be sure no damage was done, THEN (hopefully) I'll properly assemble the front end using the procedure you previously described. Then, I'll cut an aluminum pie pan down for "shim stock" around the stem hole in the upper triple clamp. Then, maybe I'll ride it??

Out of curiosity, do you use a digital torque wrench or the standard beam type? I'm trying to get 10ft-lbs on the lower triple clamp pinch bolts, but that beam-type torque wrench seems to have +/-50% accuracy, so who knows what the torque value actually is?

[canyncarvr]

Both my wrenches (ft and in/lb) wrenches are clicker types.

Torque wrenches are funny animals. A cheap one ain't likely no good at all, and a spendy one ain't no good (probably) if it isn't taken care of. Don't use a torque wrench to take stuff apart for one thing (don't use force past the click)...don't store it set to a high torque value, don't drop it, and have it calibrated once in awhile.

A lot of that is maybe just voodoo on my part......

Time before last I had mine calibrated, it came BACK wrong. First quadrant (12-3 o'clock) readings were not at ALL what 3rd quadrant readings (6-9 o'clock) were. I was tightening the top triple on my bike when I first noticed it. I have a good idea what 14ft/lbs is..and I was a good bit past that..and it hadn't clicked yet. I sent it in again. NOT to the same place. It came back all better.

My experience is the low ranges of any torque wrench aren't too accurate. My 150ft/lb wrench at 12ft/lbs? I don't trust it at all. Thus...two wrenches.

Besides that, there is a good amount of bolt movement in the triple clamps, them being split as they are. Not the same as bolt/nut or bolt in a threaded hole. IMO anyway...

[wanaride]

I removed the wheel, fender, forks, and handlebars, and I slowly rotated the lower triple clamp (still attached to upper clamp) and did not feel any catching whatsoever. I also did not feel any play in the triple clamps.

I completed the disassembly and did not see copper/brass/shiny metal through the races, but I did see what looked to be an imprint of the individual rollers on the races. I cleaned the bearings & races, greased them, and put them back together. I overtightened the steering stem nut, then loosened it so it spun with my fingers, then I tightened the nut just past finger tight. I called it a night at this point.

Next, I will insert some shimming material around the stem in the upper triple clamp hole. And it sounds like it is time to look for a good torque wrench!

[canyncarvr]

Those 'imprints' are the marks I was referring to:

'If you see marks where the tapered rollers have been moving...'


Not necessarily a big deal...but as long as it's apart, rotating the race would have been good.

Maybe next time..........


What it's TIME for is to go RIDING!!!

[wanaride]

Well, it appears that I have finally reached the point referenced by Vince on the preceding page...the bearings must be TOAST.

When I was disassembling the front end (wheel, fender, forks, and handlebar), I could rotate the triple clamps and I felt no catching.

I disassembled the triple clamps, cleaned and greased the bearings and races, then put the triple clamps and steering stem back in. I used the tapered bearing install procedure Brad described. I inserted some aluminum foil-type of material around the stem hole, torqued the steering stem nut on top of the upper clamp, and slowly rotated the assembly, and...

I felt catching all the way 'round.

I took everything back apart, put more grease on the bearings, and put it back together. Once the steering nut (under the top triple clamp) was just past fingertight, I rotated the assembly without the upper clamp and I felt no catching. When I placed the upper clamp on the stem and snugged up the steering stem nut (above the clamp), again, no catching. BUT, when I torqued the upper stem nut to 33ft-lbs and rotated the assembly, I felt the catching.

So, I presume that the bearings do indeed need to be replaced? If so, can you give me a recommendation for replacements? Pivot Works? Is it difficult to replace the races?

[IdahoCharley]

If I'm reading your post correctly it does not seem to me to be a bearing related "catching".

The steering stem nut should not be preloading or changing the load on the bearings it is just "clamping" the upper clamp to the stem. I guessing the shim stock may be catching on the bearing tightning nut as you turn the upper triple tree.

P.S. Maybe applying more pressure on the upper dust seal over the top of the upper bearing causing a catching???? Something binding against the spacer over the bearing adjusting nut???? Adjusting nut burrs???

[2001kdx]

I've used AllBalls bearings as replacements and they've never given me a hassle, I can always find them at my local dealer too.

[wanaride]

Charley, I thought the same thing, so I removed the shim stock and duplicated the tests; the catching was still present. I'll check this again to be sure.

I don't understand how I feel no catching when the upper clamp's steering nut is NOT torqued, but when the upper clamp's steering nut is torqued I do feel the catching. I thought that if the bearings were the problem, I would feel the catching whether the upper clamp were in place or not?

And another thing. I have cleaned/greased these bearings annually and have never felt this catching on reassembly. I also didn't feel the catching when I reassembled the front end after the KX fork swap in January. The only thing that's new is...the "proper" tapered bearing install procedure! Maybe I'm not doing THAT properly...
- while rotating the stem, slightly overtighten the lower steering stem nut.
- release the tension on that nut, then tighten just past fingertight while rotating the stem.

If I replace those bearings when they don't NEED to be replaced, well, that will just make my day!

[wanaride]

OK, I checked the front end again this morning:
- lower stem nut just past finger tight and upper clamp not installed, no catching during stem rotation.
- upper clamp installed and upper stem nut torqued, with or without shimming material around stem, I feel catching.

I'm beginning to think I'm worrying over nothing. There is probably something going on, but I can't figure it out. I did notice that the lower stem nut does "catch" on the threads as I tighten it on the stem; could that be at play here (no pun intended)?

Maybe I should just put the thing back together and ride it? After looking at a picture of Wibby's stem and bearings in a different thread, my setup seems golden!

[Indawoods]

Did ya swap out the bearings and races yet?

Sometimes you just have to replace parts.....

[IdahoCharley]

The following is totally a Wild Ass Guess!!!

If I'm understanding the post correctly the lower stem nut (which is a spacer for the real bearing adjusting nut) seems to catch on the stem as it turns. Then yes this could be what you are feeling when you tighten down the upper triple tree securing nut.

My thought - bearing set-up procedure and checkout prior to adding upper TT is good.

Then as you add the upper triple tree and the upper TT securing nut you slightly stretching the stem - just enough to allow the spacer to remain stationary as you turn the upper/lower tiple tree/stem 'fixed' assembly. Spacer is likely binding on the the dust cover and the stem is turning within the spacer giving the "catching" sensation.

Easy to check - does the stem spacer nut and adjusting nut turn together??

[wanaride]

Uh, I feel embarrassment coming on...what do you mean by "...lower stem nut (which is a spacer for the real bearing adjusting nut)..."? What is the "real" bearing adjusting nut?

When I look at the microfiche for my 2003 KDX200 (frame page), the lower stem nut I'm talking about is PN 92015. This nut (92015) is screwing down the stem and onto the dust seal of the bearing. I see PN 11012 on that same drawing ("steering stem cap"), and I figured this was the dust seal on the bearing. Therefore, I am screwing PN 92015 down the stem and onto the bearing (11012 and 92047).

Is the lower nut (92015) supposed to apply pressure to something other than the bearing dust seal??

What is the "stem spacer nut" you referenced above? Are you referring to the typically required spacer below the upper triple clamp in a KX conversion? If so, I'm not using that; I'm using washers above the upper clamp.

Thanks for sticking with me on this!

[IdahoCharley]

What is the "stem spacer nut" you referenced above? Are you referring to the typically required spacer below the upper triple clamp in a KX conversion? If so, I'm not using that; I'm using washers above the upper clamp.

My bad!! I looked at the picture in the thread thinking it was your bike - so yes, I thought the you were using the old KX stem nut as your spacer below the upper triple tree. My apology for not following this thread more closely.

I don't have a clue then what might be happening to cause the catching when the upper triple tree is installed - If the whole assembly is turning together i.e. lower triple tree/upper triple tree/ adjusting nut/ spacer washers/ and stem cap. The engineer in me says it should not be the bearings based upon what you have done and checked - but I've been wrong before.

[wanaride]

Charley, I just verified that the entire assembly (upper nut, stem washers, stem, upper clamp, adjusting nut, dust seal, and lower clamp) rotates together.

Guess the only thing left to do is replace the bearings. Oh well, I just wanted to exhaust all other possibilities first.

[Indawoods]

Reeeealllly?