06 450 Forks

I have a question for you guys. I purchased an 06 450 last December and noticed that when going through large whoops that the fork makes a thunk or clunk sound when rebounding. Have check steering head and internals, everything seems to be ok. Is this just the fork rebounding hard? Last forks I have experience with were on an 02 YZ250 (smoker) and they never made a noise like this. I know these are a bit different but am wondering if I should be concerned.

Im not exactly a suspension guru, but for this question, I may not have to be. Check your axle nut, it's aluminum and only needs to be torqued to 20-25 ftlbs (right guys?) and it has a tendency to vibrate loose. I noticed the same thing, with some handling issues and and I told dad and we checked the bike over twice only to find out the axle nut was loose. It may be something in your suspension, but like I said, I don't think I'm the qualified person to talk about forks. Gray??

It sounds like the top out spring may have hit hard due to fluid aeration. Check your forks for trapped air and bleed any out before you ride again. That should solve your problems. :thumbsup:

Bleed forks everytime before I ride. Sometimes out on the trail for hours at a time. Have not found axle nut loose ever. Sounds like fork rebounding to me I was just wondering if this in "normal"?

When my forks were serviced last month (06 YZ450 forks) I was told that "you got this just in time". It seems that there is a master nut that holds the internals together in there and the end of that bolt is shot peened to hold the nut on. The fork servicing company said that someone must have been asleep at the factory as one side was not shot peened and the nut turned one revolution and fell off onto the floor. He said it would have certainly destroyed my internals had it let go out on the track. Not to say this is your problem but keep this in mind.

Sic

"Peened", not "shot peened".

Peening is the process of striking the exposed threaded end of a stud or bolt to cause it to be too large to allow a nut to unthread off of it. Shot peening is a surface strength enhancing procedure designed to relieve surface stress by blasting a steel part with metal shot for a period of time.

I would get them disassembled very quickly and not ride on them until then. It is a great time to service and or revalve....remember to service the shock too.... :thumbsup:

Forks and rear shock were resprung and revalved last spring. This noise was noticed before I had that done and again after. Asked the boys at Vickery (very reputable local shop) to check into this and make certain nothing was amiss. I have been assured that all is well. Doesn't happen every time the forks rebound, I just notice when it does as it is distracting at the least.

Have heard the same noise and can feel it as well and was told ever thing inside forks was OK. Suspension re-valved by Noleen. I just live with the clunk now and then

Maybe it has something to do with the oil weight that your run? I have 7wt in mine and haven't heard a peep out of the forks.

Im not exactly a suspension guru, but for this question, I may not have to be. Check your axle nut, it's aluminum and only needs to be torqued to 20-25 ftlbs (right guys?) and it has a tendency to vibrate loose. I noticed the same thing, with some handling issues and and I told dad and we checked the bike over twice only to find out the axle nut was loose. It may be something in your suspension, but like I said, I don't think I'm the qualified person to talk about forks. Gray??

I believe the book says 75 foot pounds, I torque mine to that every time and have not had a problem do not deviate from the stock torque on the axle I would hate to see what would happen if there were a failure.

The '06 front axle nut is Aluminum. The spec in the manual was carried over from the earlier models, which used a steel nut. I wouldn't go as high as that, and I don't. 50-60 should be plenty if the tightening and clamping procedure is correctly followed.

Mine does the same thing when going through whoops. Checked everything out... couldn't find anything wrong. Guess it's something we will have to learn to live with! :thumbsup:

:thumbsup: I had the same noise when going through whoops. Found the forks had air.

I bleed the air out every time we stop for a rest. Im going to invest in a set of the quick air bleeders.

I talked to someone at Yamaha and they said they would check into my problem. They called me that same day and found that some of thier support riders were experiencing the same thing.

Thay also advised me to bleed the forks before starting each ride.

Hope this helps.

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