rear shock kickin me over the bars...

[Tommy 17]

i'm having a problem with my rear shock wanting to kick me over the handle bars when i hit bumps... i finally got a video of it today i'm gonna try to post it so u guys can see whats goin on and mayb tell me whast wrong... i think its my rebound but i'm clueless... ok the video won't post so i'm gonna upload a screen shot and work on the video... i gotta host it from somewhere...


my set up right now is stk front shocks (still waiting on my arens a-arms so i can put on my elkas), elka converted rear shock for 160 - 175 gncc i'm 155lbs without gear... so i'm right around 158lbs with gear on...

could my problem just be the SSD in the back and the stk front shocks... right now its to the point if i hit a bump in 3rd gear it nearly sends me over the bars... i use to be able to hit this bump in 4th gear no problem b4... now 3rd its nose diving really bad... i'm on the gas the whole way not letting off and as u can see i'm wayyyy over the back...

[Ralph]

ill host the vid for u just give me a minute

[Tommy 17]

thanks ralph...

and i know the jump b4 the other one in it that i hit is super small... but stk fronts suck:( and its all i got within 20 mins of me haha so don't bust one me for it...

[Ralph]

here u go:D

Tommy Vid (http://www.randrcoatings.com/images/tommyisagirl.wmv)

[toomeyshee87]

i had a problem with that when i only had my PEP ZPS up front and stock in the rear, but i would think it would be the exact opposite with your setup?? hmmmm interesting:huh

[Ralph]

i had the same problem with mine this weekend, turn down the rebound and maybe go down on the compression too...

[Berry]

ok tommy your vid is really blurry but im shure you know that already :). from what i see, the bumb is really too small too be hitting that fast! im shure if you hit it slower your rear shock doesnt spring you? do you have astock rear shock? ok when you hit this small bump, your front shocks are absorbing it but when your rear hit it it spring you, because your shock is too stiff. what we do it take ALL of the rebound out. look in your manual about it. i have too go now but i will get back with you on ways too correct this! hope that helped peace

[Tommy 17]

i've hit it harder then this... and i've hit it on my friends quad (totaly stock 400) same gear with no problem of it kickin me over the bars...

its not just this bump thats doin it either... its everyone i come 2... this is just one that i had on video and shows a good picture of what its doin...


i can be running 4th gear up a logging road and hit a small dip or a lil bump and my rear end comes way up off the ground... its like the high speed hits are WAY to stiff for me...

[Berry]

ok, i think i know what it is. next time, try scotting your butt way back too the back of the seat then right as your front wheels get close too the jump, hammer the throttle. that should raise your front end. also in the air try giving it gas, the momentum of the tires will bring the rear down. also try down shifting, you might be in too high of a gear, causing your engine too lugg and not having enough momentum too carry your rear over. try those

[Ralph]

id hate to say this, but eat some of the deermeat ur have ready for raush(u better have some) and gain a little weight... lol

[turnandburn]

what is your rebound setting and compression setting? Your shock maybe packing and is compressed all the way or to much and not enough travel left to absorb bumps because of this.

Looks like fast rebound to me...:eek2:

[Pappy]

Originally posted by Rico
Looks like fast rebound to me...:eek2:

thats where id look first tommy.

[theTman]

tommyisagirl... lol good 1 ralph

[Pappy]

Originally posted by Ralph
id hate to say this, but eat some of the deermeat ur have ready for raush(u better have some) and gain a little weight... lol

and you weigh about 3 pounds less then tammy:eek2:

[SnellCRP]

Like they have already said I think your rebound could be turned down, but it could also be the preload on the rear spring. Try to soften it up if the rebound adjustment dosen't fix it the way you like it.

[Berry]

hey dude, just got off the phone with joe byrd. we were talking about different suspension setups and he said its best too turn your rebound ALL the way down. thats how i have mine and it rocks. you can push your rear down with your hands and it will raise back up very slow. try that

you can correct the problem pretty easily by using your own weight. otherwise get the rebound down.

pack on about 15 pounds too, you're smaller than my ex. :D

[86atc250r]

Kicking is a problem I've experienced with every aftermarket or OEM rebuild shock I've had. I've found no amount of adjusting on the compression or rebound damping seems to cure it (although you can somewhat improve it if either is off very far).

Your trouble likely stems from the problems of the stock rear end geometry made worse by lowering the quad with ZPS, SSD, or whatever acronym you choose to use.

The problem is this - when stock, the 400EX's travel is too high in the rear - this isn't a big problem for the stock shocks because the tall ride height offers enough down travel to keep the problem from getting out of hand (although it still exists, many casual or inexperienced riders won't notice it).

When you use a ZPS style shock, you reduce the ride height and down travel, this is when the rear end problems become very apparent.

If the shock setup is really good, the quad will be rideable & you can learn to live with the kick - but if the shock setup is not spot on - the results can be bad enough to be flat dangerous (I've had at least two setups that were almost unrideable).

For now, take all the ZPS out of your rear shock and it will help (set your rear frame to ground clearance to match the front). It will also likely get a little better when you put your fronts on and you can make the front match the rear.

To really fix the problem, you may want to consider going to something like the GT Thunder linkage or by moving the upper rear shock mount.

[Taco]

what would the effect be if you added the GT thunder linkage to a rear elka that is already set a tad stiff?

[JOEX]

Is a rebuilt stock rear without ZPS/SSD an acceptable set-up?

[86atc250r]

The GT Thunder linkage does two things - it changes the leverage ratio, making the shock feel softer and it lowers the travel in the chassis, giving you more down travel at a particular ride height.

JoeX - yes, but you will still notice more kick than someone with an upper shock mount that's been moved or is running a different linkage setup.

[HayWire]

Sup man I had a CR500 which used to do something like that ,turned out the shock was R@@Ted It needed Regassing and the shaft needed to be recromed and hardened ...
Could be your having a similar problem ...

Best Of Luck !

[Tommy 17]

which way do i have to turn the rebound to make it slow??? toward soft or hard... i'd assume soft but i want to be sure so i don't get hurt over turning it the wrong way...


gabe i hope mine isn't like ur explaining... a stock shock looks like a million dollars compared to this thing look bad... if it keeps this up i'll sale it and go back to stock... i think i just need to get it dialed in thou and hopefully i'll be ok...

haywire it has 1 ride on the new rear shock just rebuild, revalved, and recharged...

ralph i'm really low on deer meat... i'll try to get u some thou... and i've gained 20lbs this year alone since u last saw me... when u saw me last year i was 130... i'm 155+ now... haha


dan man i do use body language to correct... no matter what u do it just kicks u over the bars... u can stay back far as u want... ur goin to nose dive...

[CTmxyfz]

dads stock 400 rear shock does that. go figure.:p Tammy and Ralph don't weigh anything. Where was this dear meat at rausch? I never got any?:(

[Ralph]

Originally posted by CTmxyfz
dads stock 400 rear shock does that. go figure.:p Tammy and Ralph don't weigh anything. Where was this dear meat at rausch? I never got any?:(

yeah and u weigh what? a big 150,,,:rolleyes:

[A4StrokeGuy]

My stock rear shock did that all the time last year during MX races. I got it rebuilt by TCS this past winter with ZPS and the other cool little features and it seems to have taimed it down alot when it comes to throwing you over the bars. I've raced on it twice so far this year and the first race it beat the crap out of me, but i fiddled with the rebound and compression and it rides like a dream now. I found just make little adjustments over and over again until u get it where u like it.

jordan

[CTmxyfz]

Originally posted by Ralph
yeah and u weigh what? a big 150,,,:rolleyes:


hey hey. 140 son.:p


Ralph, you go to etown alot? how is it? Im thinking of going there once my quad is ready.

[KY Woods Rider]

Originally posted by Tommy 17
which way do i have to turn the rebound to make it slow??? toward soft or hard... i'd assume soft but i want to be sure so i don't get hurt over turning it the wrong way...

You've got it bass-ackwards. Hard rebound = slow rebound. Soft rebound = fast rebound.

Just think about it the same way you do compression.
Hard compression means the shock compresses slower. Likewise, hard rebound means the shock extends slower.
Soft compression means the shock compression faster. Soft rebound means the shock extends faster.

[400exBro]

Is the elka linkage for the Elka LT shocks the same as the GT thunder rear linkage????



As for rebound, i had my rear shock for my ex turned as fast as possible for mx riding....
when you look at it for mx racing/riding you want your shock to come back to full travel as fast as possible so when you hit the next bump your shock isn t still compressed giving you less shocks travel and may cause bottoming out and a rough ride, in the end throwing you over the bars....

just think of it as a pogo stick bouncing up and down, you want that spring to return back to normal quickly before you end up compressing the spring again, if it doesn t return back to normal you will end by compressing the spring will it is still trying to return back to normal = less travel and a rougher ride....

does any of this make sense??? i can draw this and explain it on paper but don t know if i explained it well enough in writing.?

[Tommy 17]

bro i'm not racing much MX... i'll hit the track but i want to concentrate on GNCC...

thanks ky woods rider... see i would did it backwards and got hurt:blah:

[KY Woods Rider]

Originally posted by 400exBro
just think of it as a pogo stick bouncing up and down, you want that spring to return back to normal quickly before you end up compressing the spring again, if it doesn t return back to normal you will end by compressing the spring will it is still trying to return back to normal = less travel and a rougher ride....

This is commonly known as packing. The rebound is so slow that the shock doesn't have time to extend before it hits the next bump. This will not be a problem on a single bump or jump, but it will cause a severe kick in whoops or any type of decent size repetitive bumps.

I don't know if I'm any better at explaining it or not, but I'll give it a shot.
You hit the first bump and the shock compresses and then starts to rebound, but it does not rebound fully, so you hit the next bump and compress it even more, and then the next bump compresses it even farther. Finally, the shock either bottoms or it gets so low in the travel that it's extremely stiff. Then when you hit the next bump it's like you don't have a rear shock at all, which will cause the rear-end to jump up in the air, and when the rear-end finally comes up in the air long enough for the shock to rebound fully, you either endo or go flying over the bars.

Also, one of the characteristics of packing is that the rear-end will start hopping from side to side in the bumps, where a fast rebound usually results only in a straight up kick.

[sprtrx300ex]

Originally posted by KY Woods Rider
This is commonly known as packing. The rebound is so slow that the shock doesn't have time to extend before it hits the next bump. This will not be a problem on a single bump or jump, but it will cause a severe kick in whoops or any type of decent size repetitive bumps.

I don't know if I'm any better at explaining it or not, but I'll give it a shot.
You hit the first bump and the shock compresses and then starts to rebound, but it does not rebound fully, so you hit the next bump and compress it even more, and then the next bump compresses it even farther. Finally, the shock either bottoms or it gets so low in the travel that it's extremely stiff. Then when you hit the next bump it's like you don't have a rear shock at all, which will cause the rear-end to jump up in the air, and when the rear-end finally comes up in the air long enough for the shock to rebound fully, you either endo or go flying over the bars.

Also, one of the characteristics of packing is that the rear-end will start hopping from side to side in the bumps, where a fast rebound usually results only in a straight up kick.

Well said

[barry rhames]

even with the stock shock slowing the rebound all the way down isnt that extreme it still should be slower compared to an axis or so i just had my stock shock rebuilt and slowed all the way down its still alittle fast .thats the bottom screw turned all the way out and the compresion set a little softer seems to make it work pretty well all so tire pressure makes alot of differance 4 pounds instead of 5 or 5.5 will suck up alot more believe it or not drop the air pressure and then work on the suspension to make it work for you I just set up my friends 400 and hes probably your size and he liked it

[Tommy 17]

i turned the rebound 1/2 turn in from total hard...

then i turned the compression 1 click in from soft and it works half decent... i need more time to play with it but theres snow on the ground right now... i can't ride in the snow:(

turning the comp up is just gonna help it kick you harder. turn the comp down all the way and turn the rebound position up so when you push the rear down it comes back the slowest.

if you get confused just push the rear grab bar down and youll see which way you have to go.

hell, turn the rebound all the way hard and get out form under the quad and push it down, then turn it all the way the other way and get out from under the quad and push it down again, this will give you a good idea of what the rebound does.

one thing, are you sure the oil didnt leak out of the shock? maybe thats why its acting that way?

[Hammer trx450r]

also dont go so drastic on the changes it only confuses the situation

[Ralph]

from now on when we talk about rebound its Slow and Fast.

on the 400ex shock, turning it CW is slower, turning it CCW and its faster.

If it kicks u over the bars then its rebounding too fast. The compression should not have much to do with kicking u over the bars, cause compression is more like the force needed to push it down.

it could prob have a littlebit to do with kicking u over but u should beable to fix that with the rebound, but u still have to adjust the compression.

[Tommy 17]

well i really can't do much now till i get my arens a-arms... one i get those i can put the front shocks on it and set the ride height... from there i'll play around with the rebound a little bit more... my problem b4 was the shock was set on FAST as possible rebound... soon as it hit hte bump it would rebound to fast... i need to find a better place also with many bumps in a row so i know if its not 2 slow...


it just takes time... and it don't help that theres 2 inches of snow on the ground!!!:grr: