what to ask for when getting a shock revalved

[rustyhondas]

86 atc 250r
86 trx shock
86 linkage w/adjustable dog bone
06 450r swingarm

Shock is clean but leaks oil at shaft and has like a half inch of springyness because of it
not totally blown Like a pogo stick yet, but on its way

It has no static sag at all , this needs fixing
It it stiffer than it used to be with the stock swingarm and atc shock
The thing is I just rode the damn thing for 20 years and never messed with anything . Never touched the knob,screw on bottom ,or preload. I don't know what good or bad would be.

Riding 110s 200s hard tail all kinds of 4 wheelers in various conditions.. I don't know nothing I just keep them running and ride them .

I don't know how high my R should be in the back it used to be what I thought was low . So I made it low again . 13.75" from top of carrier section of swinger to under. Frame at seat latch ,no sag
I don't particularly like or dislike. This height ,it just has always been like that
If there is something to gain by rising it up a little I'm all for it
If it should be higher but have more sag when I get on it, it would make sense to me . I'll do it if told to , I want it to be set up slick , not just the random crap I am used to

I am going at this project this time wanting to do it rite,I want to get my shock back and be surprised like I never knew what I was missing .

I am not a racer , I just haul ass around and ride in the woods , paved roads , mud , what ever .all terrane

I want the shock good so it's safer hauling ass down rough roads , and can take a natural jump over a hill .
Ride quality not too soft not too hard
Ride height not too high not too low
I have no idea what kind of wrench I have thrown in the gears with the 450 swinger , and the bike is not ready to ride , I need the shock to be good before I do anything

I don't want to screw the thing up with my ignorance , it's going to be like 300 bucks when it's all said and done for the upgraded guts and rebuild, great price for a custom shock no doubt.
But I want to do it once and be pleased with it

[Jmoozy27]

Pm onformula1 with the above post and he will be able to help

[tripledog]

^^^ Agreed. He is THE "go to" guy regarding suspension repair or upgrades.

[rustyhondas]

We have been PMing

The thing is he has some questions rite fully so as a builder , and I just don't have the answers

I just don't know what I don't like about the current set up, I don't trust that how it was or how I think it should be is rite

It's like I can ride the tires off any old piece of
S hit , my opinion on set up , or wants and needs of a shock are unknown to me,
That coupled with the 450 swinger changing the geometry

I hope someone around 200 pounds or less with a 06+450r swinger who does not jump school busses with the thing
Can tell me "do this"

[Jmoozy27]

I don't know much about revalving or redoing shock either so I just sent my stuff to him and let him figure it out. Sounds like regardless of what you want, the shock is in need of a rebuild. New seals, and internals will likely do some good along with a fresh nitro charge.

It seems you have 3 options:

1) Leave it how it is

2) Rebuild it yourself

3) Pay someone to rebuild it

Choice is yours...

[Flyingw]

https://www.schmidtyracing.com/rebuild-services-s/1848.htm

[loganm]

Tell them what you like and don't like and tell them what you want. IMO sounds like the shock is in need of a rebuild along with a softer spring.

[atc300r]

Give these guys a try.http://www.shockaholic.net/html/services.html

[barnett468]

Ok, well I certainly don't consider myself the best suspension engineer in the world but I have done a boat load of suspension engineering and can tell you that no shock builder can even begin to help you unless you supply them with a lot of info that you probably cant supply . They need things like the weight of the bike in front and rear and length of the arm and all the linkage measurements and shock travel at different elevations/intervals of wheel travel etc so they can plot a graph to determine the leverage ratio which is likely less than ideal because of all the changes . Without this info, all they can really do is make a best guess which will not produce ideal results.

I can also guarantee you with 100% certainty, that even with all the info, it is highly unlikely that the shock would turn out just the way you want the first time out . We had to test many different combos and settings at Kawi before a bike performed just the way we wanted it to . This goes for all aspects of a vehicle which is why they have R and D departments.

In your case, I would do as much testing and measuring as you can before sending the shock to anyone . I have a few things to do right now but will be back in a few hours and suggest what I think your best plan of attack might be but one of them will be to get some sag in the rear . I typically set thinks up so the suspension sags around 1/3rd with the rider on it . Another thing will be determining if it bottoms out after you get the right amount of sag in it, and whether it bottoms too often/easily or too hard.

As far as how high the rear should be, imo, the stock ride height was very good . if you raise the rear it turns quicker but becomes more unstable at higher speed . if you lower the rear, it turns slower but becomes more stable at high speed . if you were racing in the desert, you would want to sacrifice quick turning in exchange for more high speed stability . if you were riding very tight trails, you would want the opposite . my guess based on the type of riding you do is that you would prefer the stock ride height.

[barnett468]

.
Ok, I know nothing about this conversion other than one what little I found online about it, however, since I have done a fair amount of suspension engineering, I think I "may' be able to help you enough to figure a couple things out and at least point you in the right direction providing you are willing to put in some minor effort.


I just don't know what I don't like about the current set up, I don't trust that how it was or how I think it should be is rite It's like I can ride the tires off any old piece of S hit , my opinion on set up , or wants and needs of a shock are unknown to me, That coupled with the 450 swinger changing the geometry

If you don't know what you don't like about it then there is nothing so horrible about it that needs to be fixed so you could simply get the shock fixed and be done.



I want the shock good so it's safer hauling ass down rough roads , and can take a natural jump over a hill

What is unsafe about it?

What do you not like about it?

Does the rear bottom or even come close to it off of any jumps?



It has no static sag at all , this needs fixing

Does it take much force to push it down around 1"?



86 trx shock

What year is it . Race Tech says different years came with different spring rates.



06 450r swingarm

How much longer is it than the stock arm?



86 linkage w/adjustable dog bone

I have read that the atc250r and trx250r linkage will not work properly and might hit th frame . There are a few threads online offering different combinations of linkages to make it work, so t is possible that you will need to change something unless you know the parts you have will work . Some of the tests I listed below may give us some insight.



it's going to be like 300 bucks when it's all said and done for the upgraded guts and rebuild, great price for a custom shock no doubt.

If that includes, a race tech race valve and bladder and bottoming cushion and seal and bushing and spring, that's a god deal.



I hope someone around 200 pounds or less with a 06+450r swinger who does not jump school busses with the thing Can tell me "do this"

I have seen a 450r swingarm on an 86 250r but i doubt you will get lucky enough to have someone post that does.



Ok, there are a few different ways to approach this . Below is just one of them and it is the simplest way I could think of . There are a lot of steps but they are all easy . With the exception of possibly going to the hardware store, it might take you around 2 hours to do them all.

The info you obtain should help us closely narrow down spring rate, spring preload and compressed and extended shock length.

If you push down on your shock with the spring off and it still has damping, the info may also at least tell us whether you need more or less damping

what exactly will the place that quoted you $350.00 do?

does that include modifying the stock valving or changing it to a race tech gold valve?

does it include a new spring?

will they modify the valving one time for free if it is not what you want the first time?

front and rear tire size?

rider weight?

a race tech gold valve will provide the best overall ride if it is set up properly, however, based on the type of riding you do, its unnecessary, so if you are on a budget, you can see if you can find a place that can modify your stock valving.


Here's Race Techs prices.

http://www.racetech.com/

CLEAN SHOCK, NEW OIL, SEAL, BUSHING & GAS .......... $160.00

BLADDER AND BOTTOMING CUSHION IF NEEDED ............. $50.00
.
BOTH THE ABOVE PLUS GOLD VALVE ..... ....................... $430.00

COST TO REVALVE GOLD, CLEAN, OIL & GAS................... $125.00

SPRING .................................................. ................. $120.00


You can also try here.

http://www.schmidtyracing.com/


0. fill your tires to the psi you use and provide tire size

1. have someone lift up on the rear grab bar until the suspension just barely tops out then measure the distance from the ground to the center of the grab bar . pt a mark on the bar to measure to.

2. have someone lift up on the handlebars until the suspension just barely tops out then measure the distance from top of the lower fork tube to the bottom of the tripple tree.

3. put the bike on a stand or milk crate

4. install shims under the bike or stand until the front and rear wheels barely touch the ground then kneel down and take a photo of the from the side that looks similar to the one on the bottom of the page.

5. distance from top of front tire to bottom side of front fender . put a mark on the bottom of the fender that you can use to measure to.

6. measure the distance from top of the lower fork tube to the bottom of the tripple tree.

7. measure the distance from ground to the mark you put on the rear grab rail.

8. distance from the top of the axle carrier/housing to the bottom of the rear fender . put a mark on the top of the housing and bottom of the fender that you can measure to.

10. distance from the ground to the top of the seat at the lowest part which will be basically straight up from the swingarm pivot bolt.

11. remove the rear shock and measure the length from the center of the mounting holes . it is probably 16".

12. measure the length of the spring

13. remove the shock spring.

14. re-measure the length of the spring.

15. measure the length of the bottoming cushion.

16. measure the length of the shock shaft with the shock fully extended.

17. compress the shock all the way to see if it is bent then release it to see if it returns by itself.

18. fully extend the shock and reinstall it without the spring.

19. put a floor jack under the rear axle carrier/housing and jack it up one inch using the marks you made to measure by.

20. measure the length of the shock shaft or the length of the shock, whichever is easier.

21. jack the rear up another inch then measure the shock

22. jack the rear up another inch and measure the shock.

23. continue this process until you run out of travel.

24. lower the rear after you are done.

25. remove the front springs.

26. get a friend to help you carefully lower the bike to the ground . be careful that the rear tires don't smash into the fender . if the tire are going t hit the fender, remove it.

27. have someone fairly heavy sit on the bike once it is lowered . this will reasonably simulate a worst case bottoming out condition.

28. measure the distance from the bottom side of the frame under the engine to the ground.

29. measure the distance from the top of the rear tires to the bottom of the fender . put a mark on the fender to measure to.

30. measure the length of the shock.

31. check to insure nothing is hitting the frame like the chain or swingarm etc.

32. take a photo of the bike from the chain side at chain level so we can hopefully see what it is doing.

33. if the distance from the bottom side of the frame under the engine to the ground was less than 1 1/2", raise the bike until this distance is 1 1/2" with the rider.

34. measure the length of the shock.

35. put the bike on the stand

36. remove the shock.

37. stand the shock upright with the shaft end on the bottom.

38. push the bottoming cushion down to insure it is seated against the cup.

39. compress the shock until the body just barely touches the bottoming cushion.

40. measure the length of the shock.

41. subtract the compressed length of the shock with the rider on the bike from this new number . this new number is the thickness of the spacer you need to install on the shock shaft under the bumper cup to have 1 1/2" of clearance between the frame and the ground when both ends bottom fully . in fact, this distance will actually be less under actual riding conditions due to tire compression and frame and swingarm flex etc.

42. you should then remove the shock eye and nut and take all the shock pieces to the hardware store and buy enough fender washers to equal the final number you calculated and make sure the washers are just slightly larger than the shaft and that the outside diameter is not larger than the outside diameter of the bottoming cushion cup . buy four extra washers just in case.

43. install the correct amount of washers on top of the bottoming cushion cup then reinstall the nut and shock eye and only tighten it moderately tight in case you have to take it apart again to change the amount of washers.

44. reinstall the shock and lower the bike and check the ground clearance.

45. adjust the number of washers until the ground clearance is around 1 1/4" to 1 1/4".

46. fill the forks with oil to the proper level

47. place the bike back on the stand.

48. remove the shock and tighten the nut AND put a small zip tie on the shaft and just make it tight enough so you can still move it fairly easily but not so loose it falls freely down the shaft when the shock is upright . This will be a travel gauge that will tell us how much travel you are actually using.

49. loosen the preload adjusting nuts on the shock body and rotate them until they will provide 1/4" of preload on the spring then retighten them and reinstall the spring.

50. reinstall the shock and fork springs.

51. place the bike on the ground and sit on it.

52. have someone push down on the front end once then push down on the back end once.

53. have them measure from the ground to the mark on the rear grab bar.

54. have them push down on the front again then measure the distance from the top of the fork tube to the bottom of the lower tripple clamp.

55. until you post all the information, adjust the rear spring preload until it the bike sags around 1/3 of the full travel . in other words, if the rear has 9" of travel, set it to sag 3".

56. to determine the amount of sag, subtract the bike height with the rider on it from the measurements you got from test numbers 1 and 2.

57. after setting the sag height, sit on the bike and have another person sit behind you then have someone push down on both ends and measure bot ends.

58. take it for a test ride and try to bottom it out.

59 periodically check the zip tie to see how much the shock traveled then move it back up next to the body.


https://c2.staticflickr.com/4/3765/9291071376_f3421151bb_b.jpg

[rustyhondas]

Oh fudge....GULP

200 pound rider loaded

06 450r swinger 1/4" shorter or less than 86 R swinger

I don't see any condition in which the lower sock bolt/linkage bolt
will hit the under side of the swing arm
I read that too on the web , they might of had some other combination
Of linkage

My grab bar is homemade ,not a good reference but under the seat latch is

By safe I mean that it would soak up bumpy roads good when going fast

The shock rebuild would have what is described as modern style innards

On the bike in the picture I wonder what the distance in from carrier to under seat latch is
I'm going to look in the manual if this is published

I have my homework cut out for me I recon

[barnett468]

Oh fudge....GULP

200 pound rider loaded

06 450r swinger 1/4" shorter or less than 86 R swinger

I don't see any condition in which the lower sock bolt/linkage bolt
will hit the under side of the swing arm
I read that too on the web , they might of had some other combination
Of linkage

My grab bar is homemade ,not a good reference but under the seat latch is

By safe I mean that it would soak up bumpy roads good when going fast

The shock rebuild would have what is described as modern style innards

On the bike in the picture I wonder what the distance in from carrier to under seat latch is
I'm going to look in the manual if this is published

I have my homework cut out for me I recon

ok, my computer has aprob so thisw ill brief.

if you can use a tape measure andh ave basic mechanical skills you can EASILY do the tests and will learn a lot in the process

there is no spec for the rear but i do not need one

tseat a peme asurean d havebas icm ecebr eif .

[barnett468]

Oh fudge....GULP

200 pound rider loaded

06 450r swinger 1/4" shorter or less than 86 R swinger

I don't see any condition in which the lower sock bolt/linkage bolt
will hit the under side of the swing arm
I read that too on the web , they might of had some other combination
Of linkage

My grab bar is homemade ,not a good reference but under the seat latch is

By safe I mean that it would soak up bumpy roads good when going fast

The shock rebuild would have what is described as modern style innards

On the bike in the picture I wonder what the distance in from carrier to under seat latch is
I'm going to look in the manual if this is published

I have my homework cut out for me I recon

ok, one computer back in action, the other is down for the count.

when you have time, please read thru my list . if you just take it one line at a time, it will be incredibly easy . if you just look at the length of the list, it can be a little intimidating . there is nothing overly scientific or complicated on it.

feel free to ask ANY question you want . i or others will be happy to explain anything you have a question about . there is no such thing as a dumb question.

even if your bike is stock, the frame can bottom out if you install smaller diameter tires . also, since your linkage and arm are no longer stock, no one here will have much, if any idea what effect that will have on the suspension ratio or ride height etc . from what i have seen online, three different people that have installed this arm on a atc250r or trx250r all used a different combination of parts from different bikes . well, its impossible for all 3 to be correct even though all three may "work", meaning that the suspension does go up and down and the linkage does not hit anything . Well, the the suspension on a 1948 john deere tractor also "works" .

with the info from the tests, i can plot your suspension ratio to see what it is . in fact, it is so incredibly easy to do, a 5th grader could probably do it once they were shown how . this info may or may not help us, we just won't know until we have it, but my guess, is that we can still make suggestions that will point you in the right direction without it so if you really dont want to do it, you could skip the part where you jack the axle up an inch at a time then check the shock length, however, i would not skip it, especially since you really should remove the springs to see if the frame bottoms because at that point, the bike is ready for that step.

if you want to do anything in the mean time, i would set the sag the way i describe it then put a small zip tie on the shock shaft to measure the amount of travel you are using, then test that.

go off progressively bigger jumps or go off the jump you usually go off of several times starting fairly slow then look at the zip tie then go off faster every time . once the zip tie shows that you are using the full amount of travel, stop.

if it bottoms long before you reach your maximum speed, you need a stiffer spring . if it never uses full travel, you need a lighter spring . this is taking into account that your shock has no charge in it but because of that, there is a little guess work involved but not really very much.

another option is to get a race tech gold valve installed as you want and have them guess at the setting or simply valve it the same way they would for a atc250r which is probably going to be the closest anyway, then try the bottoming test and see if you need a new spring, however, as i mentioned, no one can make it perfect the first time out unless they simply get lucky because of all the changes you made with miss matched parts.




sukl

[barnett468]

oops, also, if you put the bike on a box with the front and rear wheels just barely touching the ground and post a photo that looks just like the one i posted, i or many others here can tell if your "ride angle" is close to correct or not just by looking at it . in fact, you can even do that yourself, just look at the angle of the seat . comparing the difference by using the space between the top of the tires will only work if they are the same diameter as the originals and the bike was sitting on the ground with the same amount of sag a stock one has . also, and even though a tire may say its the same size, the actual sizes do sometimes vary a little.

[rustyhondas]

Thank you for this caliber of a response

I have not progressed down that list diligently yet

But I did give the bike some attention today

I few things I need to get out of the way first are remove the 3/4" long pvc
Spacers I put in the forks a few weeks ago when doing the seals , from playing around reading on the Internet
I did not like this tweek

Instal correct year rear plastic , be here Tuesday , been running a 84 . Its throwing off my judgement visually

Ditch the 21" mud shark tires for some 20" Ohtsu mr501s

I confirmed the shock is 16" long

Me and someone stood on the rear and nothing hits anything it should not

The stock dog bone is basically 6.75" from eye to eye and I got the adjustable one set a inch longer

I doubt that a amateur like me can tell any Ill handling from what ever that does to the ratio ,what I found messing with all of this is that the shock has a Progresive spring in it ,and after I slacked off the preload nuts all the way to the end of the threads ,
I can only get less than a 1/2" of static sag and only get 2" of "race" sag .(I hate that term)

That tells me the spring is too stiff

I'm going to put the atc shock on it and see how it feels

I will send both shocks to the builder when the time comes to rob parts and build one

[rustyhondas]

230337230338Well I got the sag back in it and the ass isn't jack up in the air like it was

The shock I was playing with turned out to have a stiff Progresive spring in it

I swapped it for the old spring and all is rite in the world again

I'm getting closer

Put Progresive fork springs and 15wt in the forks
Ditched the mud tires for some 18x11-8 duros230336

Maybe this weekend I will get it on the concrete and snap some photos to get some opinions on its stance

[oscarmayer]

if your not MX style riding or "racing" in dedicated competition, then your aggressive trail riding. Onformula1 can easily redo your shock for a fraction of the costs other's charge. some re-valving for better rebound and compression as well as spring adjustments will make a huge difference.

here is what I would tell him.
rider height
rider weight
ATC weight
length of stock swinger and then length of new swinger, there is a path needed to know spring rates for increased swinger length to ensure it rides and handles correctly.
the stock shock was never designed for any sort of performance riding in stock form. they always needed re-valving and tweaking to operate peak for each rider. it cam be the difference between gliding over some dips and bumps and bouncing across them and trying to hold in w/o crashing.

good luck.