450 RR "shuddering" ?

[offworlder]

My 09 450 RR feels like its "shuddering". This is most pronounced when applying the slightest amount of throttle, at the bottom of each gear (ie: when minimal forward force is applied).
It feels as if there is slack in the steering head, but I've checked the steering column, and there is no play there...

Could this be a loose frame or engine bolt ? An issue with the clutch ?

While I realize this is not alot of info, I'm not sure where else to look, any insight would be appreciated.

Thanks.

[Orangeshirtdude]

Maybe the rpms you're at are too low. The engine will chatter as it lugs forward at very low rpm.

The steering head can be checked easily. Put it up on a stand and pull out on the front wheel. If it's loose, you should feel it. Or you can just loosen the pinch bolt and make sure the steering nut is tight. With the front suspended, you can check that it's not too tight by checking that it swivels without friction.

[offworlder]

I did the above re the steering head, hence I'm confident its not the issue. As far as RPMs, its not "that kind" of shuddering (:-), which is significantly more pronounced, this is more subtle. Its more of a "slop" or looseness of sorts, hence my thinking it could be a frame/engine bolt.

Thanks.

[Orangeshirtdude]

Well determining whether the engine is tied down is easy enough. Just grab hold and yank it a couple of times. Or with it off, put the bike in first gear and push it back and forth against the engine. You'll see it move if anything is loose.

Maybe your final drive system is shot. If your chain is really loose on worn sprockets, you can actually skip teeth.

[offworlder]

OK, noticed the front wheel had a little jiggle, pulled it off, and the bearings look pretty crusty - red ooze all over em (dust ?), and small chunks of stuff.
(from the "in over yer head" dept.) How do I pull these out, so I can re-grease em ? Would appreciate any tips re technique, grease, etc... Strangely, there's no mention of replacing the wheel bearings in the service manual.

Hoping this'll solve the shuddering...

Thanks.

[Haychip]

If you can actually feel the wheel bearings going out (when riding), they have to be completely shot. I guessing that is not it. There should not be any play. You can pop out the seal and then the shield on the side of the bearing and re-grease them. I'm sure that the small chunks of stuff is just grease from factory assembly.

[Orangeshirtdude]

A person would have to basically ride through pools of organic solvent several times, sinking the axles below the surface each time, and then ride hundreds of miles on dry bearings for modern wheel bearings to fail that bad.

[offworlder]

I think (am hoping) what I was feeling (shuddering) was the slight slack/play in the front axle. We'll see once re-assembled.

Got the seals out easy enough, pulled piles of hardened gunk out (of the seals), there's a small spring ring in the seals that is pretty stiff. Do these need to be replaced (often) ? And how do the bearings come fully out ? Does this require a special tool ? Or do I simply slap some Bel-ray waterproof grease on their outside face, some on the axle, and reassemble ?

I see mention of using engine oil when replacing parts (in the service manual)..
Really appreciate the help guys !

[offworlder]

Update: even after replacing the seals, and aluminum spacers, there's still a slight amount of play in the front wheel. With the wheel off the ground, I can grab it at the top and bottom, and move it from side to side (left to right) and there's a few mm of movement. Is this normal/acceptable ?

Thanks.

[Haychip]

No, there should be no play. If the play is in the bearings, they are shot.