Two Stroke Motocross
Two Stroke Motocross Forum => Technical => Topic started by: ACMX on April 20, 2011, 05:53:54 PM
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I need some help. I'm sure it's from my crash a few weeks ago, I had hit my head so I never really checked the bike over extremely well... But I got back on it and I'm pretty sure I would have noticed if the suspension didn't compress when I got on. Anyways today i went to check on it, just casually chatting on the phone I pressed down on the seat, and nothing happened. I got on, no compression of the rear suspension. After that I found it was able to compress nearly two inches before it stopped where it felt like it was hitting someone.
Here is a video of the crash... You can see at 0:32 and 0:44 it hit the sprinkler with the bottom of the bike. What do you guys think is causing my suspension to lock?
My Crash (http://www.youtube.com/watch?v=vzyfbqIPzd4#ws)
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The only thing i could think of is if ya shaft on ya shocky's bent but i doubt a pissy lil sprinkler could do that.
When did ya grease ya suspension last? My last YZ did a similar thing, i was riding it one day and all was good for a bit then i went over a jump and the suspension went half way down and stayed there. I took it home, pulled it all to bits and greased it and it was all good.
And it was only one f the bearings which was dry and had gone abit rusty. I hope for your sake thats all it is... :D
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Alright I'll be taking the linkage apart sometime this week, thanks.
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Check your linkage bolt which connects to the shock. It may have come loose and is hitting the linkage.
If not take out the bolt any way and see if the linkage moves.
Also check the lower main linkage arms are not hitting the shock bolt.
They may have got bent in the crash.
Put your head under the bike and get someone to push down on the seat. You will see whats happening.
I doubt the shock will be bent.
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It only takes a few minutes to pull the rear shock to help isolate the problem.
I'm restoring a TM 250MX and the swingarm bolt is partially sheared,the rear shock shaft and linkage are both bent as well.I'm still trying to figure out how the previous owner managed to inflict this kind of damage on the bike.
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Unfortunately I'm not that great of a mechanic yet Sachs. I'm only 16 and don't live with my dad so I'm learning all of this on my own. I can do suspension linkage but I don't know a lick about the shock.
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Watching that vid, the rear suspensions not moving, I'd say linkage bearings.
Had a similar drama when I smashed my arm. The suspension felt dead before
I crashed and when I checked the bike over once I healed couldn't move the suspension.
Linkage bearings.
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Yeah that sucker was stuck before you crashed, it could be a number of things, lower shock bolt loose, dry linkage, I was gonna say swingarm pivot too, tear the whole ass off it, inspect everything, if it's all straight, and not too worn, repack all the bearings, with marine grade wheel bearing grease, like for boat trailers, and put it all back together.
If it's still sticking it is possible that a washer in your shock valving failed and is stuck in the shock body somewhere buggering things up you should probably go ahead and get your suspension serviced before you ride it again, as that little piece of metal will wreak havoc on the instide of your shock body
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Haha wow thanks for pointing that out guys, I didn't even notice.
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AC - did the bike sit for some time before you used it that day in the vid? Just curious if things could have rusted up pretty good since any last rides.
Apples to oranges here, but I had a 6" front fork on one of my mountain bikes lock up on me when dropping off a small wall. It HURT. It felt like metal-on-metal, but it was a problem with the valving causing one of the chambers to hydro-lock.
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Yeah it's been sitting for about a month, but in the garage. I'm hoping it's just a bit rusty and I can repack the bearings and call it good. If not I'm making a call to all balls to see if they can help me out :/ ... Applying for a job tomorrow regardless.
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The linkage was frozen :/ Rusty.
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well that's a good thing, linkage bearing are cheap. Make sure you repack em with marine grade wheel bearing grease.
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I'll see what I can get my hands on. But while we were in there yesterday we checked out almost the whole rear end of it. Lucky for me the swing arm bearings are good.
After we took the main linkage pivot bolt out, I tested to see if the swingarm could now freely swing...
;D
(http://i91.photobucket.com/albums/k287/mxboy721/p_00778.jpg)
Oh and thats my dads husky in the background ;D
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Digging that hair cut!!!
BALD IS BEAUTIFUL ;D
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Hahaha, fortunately that's not me. I'm behind the camera :P
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Have you taken your swingarm bolt out yet? Don't neglect it when you do your other bearings, it will "weld" itself to the bushes and your life will never be the same. :-[
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Thanks for the tip, I'll inspect and repack it when I do the linkage.
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Glad to hear the problem was found and it's getting fixed :)
AC, Is that what caused your crash, (you to get sideways) or was there some other factor?
Just curious cuz I'm terrible at MX stuff.
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idk. It might have caused me to crash but from what I remember I didn't notice the suspension being stiff because most of those are smooth landings and no braking bumps.
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Usually your linkage "squeaks" when it's rusted and seized.
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It must have rusted slowly since the fall series of '10 then after I parked it cause of the crash it must have totally rusted up.
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Dude, they probably have never been greased since the factory, they use just enough grease to to make it work. When I bought my 07 KX250 new the first thing I did was go through it and re grease, and anti seize everything, they were all practically dry.
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It's funny too cause greasing my linkage was the next thing to do on my checklist :P
Now where do I obtain military grade grease?
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Marine grade wheel bearing grease. any auto parts store, wal mart, etc.
HooRah!!! :P
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sweet