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I noticed today that my steering had a catch as the front end rotated left to right. I did find that the steering damper isn't rotating smoothly, but then I checked the front forks for play, and I noticed that there was front-to-back play in them.

I took off the bars, loosened the top steering nut and lower fork clamp bolts as the service manual says to do, and I tightened the lower steering nut (under the upper triple clamp). I tightened that nut as tight as it would go (tapping with screwdriver), but the play in the forks would not go away.

The triple clamps from the KX fork swap were new, and the KDX bearings and stem have about 1500 miles on them. I have put about 300 miles on the new fork assembly.

Is this normal after a KX fork swap? What else can I try to take out this play?

Replace the bearings....

Should not be any front to back play in the forks. Something is wrong! I would pull it apart and check parts but with so few miles I don't think you could have worn anything out. I believe you have a binding issue preventing the stem nut from tightening the upper and lower bearings.

1. Is your adjusting nut bottoming out? i.e. enough threads?

2. Loosening your lower triple tree clamps should allow the stem nut to shift your triple tree up the fork legs but sometimes this slip fit can bind. I suggest you also loosen your upper triple tree clamps when tightening the stem nut. Of course you do this with the bike on a stand with the front wheel hanging free so you minimize the potential for binding.

* If steps 1 is good and step 2 does not correct your problem then use a rubber mallet to help the process. With both sets of fork clamps loose and the stem adjustment nut tightened smack the lower triple tree a moderate blow with the rubber mallet in an upward direction.

Charley, when you say "adjusting nut", you are referring to the lower nut that sits beneath the upper triple clamp? That nut is certainly threaded on the stem, but it sounds like you are suggesting that perhaps there aren't enough threads for it to sufficiently tighten things up. I'll look at that tonight and post a response.

I used a rubber mallet and screwdriver to tap it around last night, and it moved a little (maybe 1/8 turn) before it resisted further rotation. I was afraid to really hit it hard for fear I would damage the bearings.

Are you serious about whacking the lower triple clamp upwards? The rolling eyes made me suspicious, but it sounds like a good idea to me.

Maybe I should just take the front wheel off when I adjust this??

Vince, I admit anything is possible here, but I've been pretty religious about pulling the steering head apart for regular cleanings & greasings, so I don't suspect that the bearings are worn out yet.

Thanks for the feedback!!!

Catching and play sounds like bearings and races to me... easy to screw up with a KX frontend install....

Indawoods wrote:Replace the bearings....

I would say they are TOASTED

Easy way to check is to dry fit the clamps by themselves (with no fork legs installed) amd feel for play. Just a thought...

Yes, I plan to do that this weekend. If I fitted them poorly during the install, surely the mileage I've put on the bike since the install has ruined the bearings.

I think my Scotts is messed up too, it has a catch in it during rotation. I must have damaged it when I reversed the link arm. There is no catch in the steering when the Scotts is removed.

I'll get the forks sorted, and then I'll worry about the Scotts.

wanaride wrote:Charley, when you say "adjusting nut", you are referring to the lower nut that sits beneath the upper triple clamp? .......

I used a rubber mallet and screwdriver to tap it around last night..... I was afraid to really hit it hard for fear I would damage the bearings.

Are you serious about whacking the lower triple clamp upwards? ......

"Charley, when you say "adjusting nut", you are referring to the lower nut that sits beneath the upper triple clamp?" YES

"I used a rubber mallet and screwdriver to tap it around last night, and it moved a little (maybe 1/8 turn) before it resisted further rotation. I was afraid to really hit it hard for fear I would damage the bearings."

I would not use a rubber mallet to tap the screwdriver to drive the adjusting nut. A regular or ballpeen solid type hammer will work just find. You have to get crazy with a hammer and screwdriver to damage the taper roller bearings by overtighting them. The adjusting nut is going to get torn up way before you are able to overtighten the bearings enough to do any damage.

"Are you serious about whacking the lower triple clamp upwards? The rolling eyes made me suspicious, but it sounds like a good idea to me."

Yes, I'm serious!

NOTES

1) Since you changed the front end over to a KX be sure the "play" your feeling isn't due to lack of adequate 'spacer filler' between the upper triple tree clamp and the stem. I suppose that depending on how the stem area on the upper triple tree was "filled" could lead to both play and possible a catching feeling; upon rotation of the steering stem with everything together. i.e. Shim stock material used or a filler bushing machined??

2. The only other possibility that I could SWAG at is the upper triple tree is not dropping squarely onto the stem adjustment screw/spacer set-up that you have. Really not anything else that I can think of which could give you this condition.

Just my two cents. IMHO the rate at which you can ruin the steering head bearings by having them too loose is amazing. My kid had this happen on a practically new MX bike. The races were pounded to junk, and the bearings were far from bearings any more. He thought "sometimes it feels a little weird", I could feel it right away just rolling it around in the garage.

The Scotts folks can fix your damper. Make sure it's not acting like a steering stop since your conversion. If it is, that's probably what broke it. I had to shim up my steering stops after installing my '03 KX forks to keep the damper from breaking.

Did you shim the upper KX triple clamp center hole to fit tightly around the smaller KDX stem?

The shim thickness is not much ( in my case I used aluminum pie-pan material to get the job done) but if left out will cause definite movement fore and aft of the forks. I left the shim out purposely for the initial run, and even when cranking down hard on the top triple clamp cap nut, the whole fork ass'y would clank after a few rough miles.

Maybe a pic would help too...
what kawagumby said and on mine I had to use a spacer (used the kx spares) to make the nut tight on the stem on the top triple clamp. Like this:

The quality of this information is just another example of how this site ROCKS!

I tore down the front end and slowly put everything back together, checking for play along the way. As best as I can tell, the "slop" I was feeling was due to NOT inserting shim material around the steering stem in the upper triple clamp hole. I couldn't find any "shim stock" like Jerry used so I punted on the idea during the conversion, but now that I know a pie pan can work (thanks kawagumby), I'll try that.

And maybe while Scotts is repairing my damper, I can have small aluminum tabs welded onto the steering stops. (I don't know if that caused my Scotts' problem, but it needs to be done anyway.)

Thanks to everyone who took the time to help me, I really appreciate it!

I bought my shim material at the local lumber yard, it's just a small sheet of aluminum about $8.00. Cut and shape the collar then tap it in there.

I bought mine at a local hobby shop for about 75 cents. Its just a piece of copper.

I checked the local hobby/craft store first and could not get out of there fast enough they didn't have what I needed and they were playing some horrible flute music on the stereo.

A hobby store/shop that doesn't have a rack full of brass stock useable for shim stock is no hobby store a'tall.

Re: '..so I punted on the idea during the conversion..'

That obviously was not the best choice?

What did you think was going to happen with that space?

Think of what was happening to the bottom tree/stem with the complete lack of support on top. Ow!!

You think of it...I don't want to.

The bottom bearing was fine? By 'bearing' I also am referring to the outside race that is fit to the steering tube. The facing on the tapered shell was not damaged?

Seeing as that race gets worn out frequently even when properly installed AND maintained. Using it (trying to) as a gimbal joint would stress it something awful.

Good on 'ya for rectifrying the fit!!

BTW..you are familiar with the proper fit/feed/care of a tapered bearing installation? Basically overtighten to seat, release, barely even 'firm' retighten?

More often than not..most people don't seem to do that. Tapered roller wheel bearings are a thing of the past. Used to be a regular part of anyone's shadetree mechancal knowledgebase.

No, I'm not familiar with that, but it seems there is a lot I'm not familiar with... Thanks for the description. That explains the procedure I read in my son's CRF70 service manual yesterday.

So after you overtighten it (I presume with a reasonable amount), you loosen it, and then what, finger tight?? I can't seem to get my torque wrench to measure my hammer/screwdriver taps!

Sounds like I need to do all of that over again (my bike and his). I'll do that once I get the shimming material for the stem hole.

Any tapered roller bearing will be assembled in the same fashion.

Basically: While moving the bearing (rotating the stem in this case) tighten the nut atop the bearings to 'firm'..the manual has a figure, around 25ft/lbs. will work.

While supporting the stem (don't let it drop), loosen the nut, retighten to barely past finger tight. I tighten it by hand, then give it another 5º or so turn.

The finished effect is smooth movement from one stop to the other, no notchy feel, no drag.

None of that will accomplish anything if the outer races are not properly seated. When driving the races in, make sure they are square to the frame tube and fully seated. You can hear the seat just like you can hear, say, a rear wheel bearing when it is properly seated. Instead of a hollow 'thunk' you hear a solid THWACK when the race hits the inside seat. Use the race from the old bearing to drive the new race into the tube.

Check it by running your fingernail around the race where it meets the frame stop. If it's not seated properly, it will be very apparent by touch.

I've not gotten one, but it seems to me that one of those 'one size fits all' sockets (the spring loaded pin type) would do nicely to torque the spanner nut. You could use the old spanner wrench and spring tool method. What a pain in the arse that is.

Thanks Brad, that helps a lot!

When I have the front end apart, how will I know if the bearing inner races are toast? For that matter, how will I know if the roller bearings need replacement? (This is probably in the service manual but I don't have it in front of me.)