Rear end setup?HELP!!!!HELP!!!!All years!!!

[socal]

O.k,I have a friend with a LSR Baja chassis and a Houser 88-89 swingarm with Elka shock.We cannot get his ride height set below 9" in the back!My stock frame 86-87 setup is set at 8" out back with room on the shock to go lower.His shock collar is ALL the way backed out,barely touching the spring and hes at 9"???There is also only 5/8 exposed shaft with rider on the bike,mine has 1 1/4 with rider on!We called Elka and confirmed both shocks are the same (they said they only made 1 shock for the 250r 86-89),both shocks are 16 1/8 length,so we put my shock on his and got the same result.We switched dogbones to 86-87 length and it lowered it but the airbox was smacking the swingarm before the shock would bottom.Next we called LSR and confirmed the chassis is a stock replacement(all mounting points in the same location),next we called Houser and the swingarm is also a stock replacement confirmed by measurements!WTF is going on???Anyone with a 88-89 running at a ride height of around 8" and what is the eye to eye length of your shock???Why is my ride height good with plenty of thread on shock body left to go even lower,1 1/4 shaft exposed,HIS collar is backed all the way out,no threads exposed and 5/8 shaft exposed and hes still at 9" ride height???Is there that much difference in linkages from 86-87 to 88-89???Does the 88-89 require a shorter shock than 86-87???His is the white/blue one.

[JoePA]

Holy crap this sounds like what I was going through!!!

here is what i found out. The 88-89 rear shock is 15 3/4 center to center. where the 86-87 shock is 16 1/4 center to center.

The 86-89 linkage is the same but the dogbone on the 88-89 is shorter than the 86-87 due to the shorter swingarm.

So....you need to see what dogbone is required for his swingarm. If it lowered the rear witht he 86 dogbne then he can re adjust the shock so it sat properly?? Check the measurement from the swingarm bolt to where the dogbone bolts to the swingarm. This will tell you what dogbone is required.

How much preload does he have on his front shocks? What is his length center to center on those? Also what is the length of his swingarm? Should be about 18.5 center bolt hole to center of carrier.

Do a complete swap of shocks and see if that does anything as long as you are both running the same travel shock....std or long.

[socal]

They are both long travel,both front shocks are 19 1/4 and he has to have the front shocks topped out(threaded down,no sag super stiff)and the rear backed all the way out just to get the ride height at 9" rear and 9 1/2" front.The dogbone for that setup is the shorter 88-89 because the chassis and swinger are 88-89.His swingarm is 88-89 length,so is mine!!!So your saying the 88-89 rear shock is SUPPOSED to be 1/2" shorter???And is that the stock shock lengts or aftermarket or both?

[trx250racer]

wonder if the rear tire overall diameter would have anything to do with it??? his rear tires look taller.

[socal]

No,tires are both 18s,just the angle!But you can see in that pic that his has a stinkbug look(rear end higher than front)...Thats the only way for it to be somewhat rideable!

[JoePA]

From what I'm finding out the factory installed a shorter shock due to the shorter swingarm on the 88-89 models.

When I called Seth at SF racing and talked to him about my setup he checked his books and the 250R for 88-89 calls for a 15 3/4 length shock.

Now for some reason some of the aftermarket the shock manufactures are making one shock for all years. Is this right??? I don't know but my guess if you found a stock 88-89 shock and installed it you should see a difference.

As far as the fronts..are they set up for his weight?

I would try swapping everything over from yours to his and you sit on his quad to see if that changes anything. Also once you have all the shocks off make sure nothign is binding.

[JoePA]

Socal...is yours an 86 with stock 86 swinger? If so I think thats why the 16 1/8 shock works on your quad.

[socal]

His fronts are fine,can be adjusted properly with the rear issue corrected.My swingarm is 86-87 Laegers -1" (88-89 length).Mine works fine,just using it to compare.So did you use the shorter rear shock to correct your problem,did that work?

[JoePA]

I have the exact same setup on my rear for a swinger and the best I could get with my works rear was 8 1/4.

I installed my PEP ZPS rear for an 88-89, which I'm not sure if it's the correct setup for what I have BUT...with it installed I can get down to 7 3/4.

The PEP ZPS shock I have measures 16 3/8 center to center but when the ZPS spring bottoms out the shock is then 15 3/4 center to center which leads me to belive that it is correct but still trying to find that out.


What baffles me is why his is sitting so high with both rear shocks?

[socal]

Originally posted by JoePA
I have the exact same setup on my rear for a swinger and the best I could get with my works rear was 8 1/4.

I installed my PEP ZPS rear for an 88-89, which I'm not sure if it's the correct setup for what I have BUT...with it installed I can get down to 7 3/4.

The PEP ZPS shock I have measures 16 3/8 center to center but when the ZPS spring bottoms out the shock is then 15 3/4 center to center which leads me to belive that it is correct but still trying to find that out.


What baffles me is why his is sitting so high with both rear shocks? Not only that,he only has 5/8 shaft exposed with rider on compared to my 1 1/4,less useable travel,so even if he had more adjustment to lower ride height,he would be robbing even more travel and eventually hit the bump stop!We took the springs off,lowered the rear with a jack to a 8" ride height and he only had 1/4" shaft exposed!:confused:

[hartwill]

Tell him its junk. He should just give me that bike and start over..lol

[JoePA]

What happens if you install your rear shock? Same thing as far as amount of shaft exposed? I'm curious if there isn't something off in regards to where it mounts to the frame?

[hartwill]

Is his rear shock compression and rebound adj?

[socal]

Same result with my shock on his.My shock on mine gives me a 8" ride height,when we put it on his,it actually raised his to 9 1/2???

[socal]

Originally posted by hartwill
Is his rear shock compression and rebound adj? Yes it is!

[hartwill]

Originally posted by socal
Same result with my shock on his.My shock on mine gives me a 8" ride height,when we put it on his,it actually raised his to 9 1/2???
With this being said check his linkage. Not the dogbone but the other. He might have one off an old atc or something.. sorry to but in.

[socal]

Ur not butting in,the more feedback the better.His linkage is 88-89,we checked that!

[hartwill]

He Probly has an 86 swinger that's 88/89 length if both of your shocks are the same length he Probly needs the longer dogbone. I'm mo shock expert but it sounds to me like that's the only difference you guys have is the dogbone and his sits at the correct height with the longer one? The only other thing you can do is measure both shocks to be sure, people like to list 250r,400ex, and 450r as the same shock, and maybe I'm wrong but they are different lengths.. what air box is he running?

[socal]

His swingarm is the 88-89 style,and his airbox is 86-87 stock.The longer dogbone causes the airbox to hit the swingarm before the shock bottoms,not good!

[hartwill]

When you put that 86 dogbone on did you set the shock to the correct ride height and preload or did you leave it all the way backed off? Do you also have an oem airbox on yours?

[JoePA]

For the swingarm to use the 88-89 linkage, the distance from center of swinger bolt hole to center of mounting hole for dogbone should be about 12".

Your Laeger swingarm, for the same measurement, should be about 13"

Check to see if his is 12" If not and it's 13" then he shoudl be using the 86 length dogbone and adjust the shock accordingly.

[dustin_j]

Part of your problem with comparing between bikes is tire size. His tires say 20" and 18", but if you measure them, the fronts will be 19" and the rears 19". I had Kendas for awhile; not my favorite. For that matter, yours might measure differently from printed size also.

It sounds like something is different on his quad. Like mentioned above, one of the links seems a likely culprit. Otherwise, remove the rear shock on both quads, put the frame on a stand with jack stands or something under the axle. Then you can measure shock length without the tires affecting the measurement. This will tell you how much different the two setups are.

What race sag is each quad at? Race sag is a safer number to setup for since it takes into account extended and compressed lengths. It would be worth measuring what extended and compressed lengths your quads need. Maybe the desired ride height would need 60% sag; which tells you that height is unreasonable with current hardware.

[socal]

Regardless of tire size,he still cant get the rear lower than 9" and thats with the threaded collar ALL the way backed out! and only 5/8 shaft exposed.Also after removing the springs and using a floor jack to set ride height at 8",he only had 1/4 shaft exposed...So he has a ton of UP travel and almost NO useable travel,like the stroke is in the wrong position!

[hartwill]

It can really only be a few things. Wrong shock, wrong linkage, wrong swinger.. I would take everything off both quads and compare including both parts of the linkage.. maybe the previous owner moved the shock mount.. take some pics of everything..

[mx91a]

Sounds like the body of the shock is too long, not allowing enough shaft travel. Get someone to lift the grab bar until the tires are barely touching the ground and the suspension has no load on it. Measure from the bottom of the frame at the footpegs to the ground and report back with that measurement.