Are there any cheap Suspension mods?


47 replies to this topic
  • Frank ZX

Posted October 07, 2007 - 02:29 PM

#21

Will someone please answer my last question.Thanks

  • BWB63

Posted October 07, 2007 - 07:22 PM

#22

You need rebound control for the track. and you don't have that; To much compression control is not good. You want to control the spring rate both ways not just compression. There is no cheap way to do this. You will give something up no matter what short cut you take.

dextron III and changing the shim stack would be the cheapest help for your weight on those forks.

  • Denn10

Posted October 09, 2007 - 10:37 AM

#23

you can ride it with the clickers full in or out you just need to do some testing when you get to track and see how you like it EVERYONES different so try a few settings and go with what you feel best with

  • walshdanielm1965

Posted October 15, 2007 - 01:25 PM

#24

Installed the Fork brace, worked great except in deep whoops. I bottomed out more than 30 times during the So-Cal MC's race this past weekend.
So if I'm correct:
1) I need to lose weight
2) stiffer springs
3) Full front end work.........

any suggestions would be greatly appreciated.....

P.S. The brace helped in the sand wash & silt bed......

  • Denn10

Posted October 15, 2007 - 02:15 PM

#25

yeah springs will help alot LOL losing weight is alot harder

  • martinfan30

Posted October 15, 2007 - 02:33 PM

#26

ya you can repl. the springs front and rear yourself if you are decent with a wrench.

  • gearloos

Posted October 15, 2007 - 04:05 PM

#27

You guys are gonna laugh but I have been setting it up myself for long time on all my bikes. I measure on a stand then I set bike up straight just touching the bar on the garage wall. I get on the bike BACKWARDS and lean over a bit to measure.
I re did it with a friend later a few times but I've always been really close already from my own. Just gotta watch out for stiction in the front end so when weight is on, kinda bounce it once or twice.
Like I said, may be wrong but worked for me.

  • Captain Midnight

Posted October 15, 2007 - 11:45 PM

#28

[COLOR="Red"][/COLOR]Cut 6" off spring, replace the 6" with PVC tubing. Switch oil to 2-1/2 to 5 weight. Set compression clickers to 6. Use flat washers on top of PVC to set pre-load. Start with 10mm. If forks bottom, raise oil level 2mm at a time untill no bottoming.

Frank, I have answered your question.

  • martinfan30

Posted October 16, 2007 - 07:33 AM

#29

Cut 6" off spring, replace the 6" with PVC tubing. Switch oil to 2-1/2 to 5 weight. Set compression clickers to 6. Use flat washers on top of PVC to set pre-load. Start with 10mm. If forks bottom, raise oil level 2mm at a time untill no bottoming.


this for your weight? what you weigh? how did this help?

  • Denn10

Posted October 17, 2007 - 10:41 AM

#30

just spend a few bucks and get the correct springs once you cut you cant go back, all it takes is one little shaving of pvc to get into your shims or the small orfices of the valving and then you gotta take apart cuz it will hamper them in use. Springs are pretty easy to change specially the rear

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  • martinfan30

Posted October 17, 2007 - 10:46 AM

#31

ya i guess that is true. just trying to be a cheap a**!:crazy:

  • Captain Midnight

Posted October 20, 2007 - 11:00 PM

#32

this for your weight? what you weigh? how did this help?


This is for Franks weight, of course.

  • BWB63

Posted October 21, 2007 - 08:36 AM

#33

I have been staying out of this one because it is for an "L" :D and I wouldn't want to be a cross poster. :crazy: No one likes a cross poster:bonk: but, sense this is about suspensions and that is what I do, I thought I would say a little something that might help:prof:

http://dirtbike.off-...l.jsp?id=332656

If you take the time to read everything in that link it should help on any adventure in cutting springs to make them stiffer.

I really think cutting 6" off the fork springs will bring your springs into serious spring bind before they could bottom out and that can cause damage. For any serious dirt riding using fluid viscosity to control the dampening of the spring is far to old school but, is still considered ok for street use and does work for light off road work.

Remember: preload of a spring only effects the first inch of spring compression. Meaning it only helps suport your weight for the first inch of travel. You only want enough fork spring preload to have the forks ride at the right fork hight when you are riding the bike. A little more preload so the front end will ride a little higher in the whoops to get the timing right but, not more spring preload to help the fork from bottoming on a hit.

Also, make sure you do not add to much fluid to the forks to reduce them from bottoming. There is a minimum and maximum for the fluid level in the fork. Lets say the minimum is 130mm from the top and maximum is 95mm from the top. Minimum level is to make sure there is always enough fluid to have for flowing through the valve.
Maximum fluid is where the volume of air is reduced to the point that the pressure will be high enough to blow a seal. I stay away from this number. On an XR650R that number is 95mm from the top and I run 110mm for most and 105mm for a few that really need the extra bottoming resistance. Hope this helps.

  • Rman of 237

Posted October 21, 2007 - 03:21 PM

#34

Good link BWB63, I read it all the way through and it makes alot more sense.:crazy: It answered alot of my own personal questions as well.

  • Captain Midnight

Posted October 22, 2007 - 12:42 AM

#35

[quote name='BWB63']I have been staying out of this one because it is for an "L" :D and I wouldn't want to be a cross poster. :crazy: No one likes a cross poster:bonk: but, sense this is about suspensions and that is what I do, I thought I would say a little something that might help:prof:


I really think cutting 6" off the fork springs will bring your springs into serious spring bind before they could bottom out and that can cause damage.

Frank is looking for a cheap way to improve suspension. He does not want to buy springs. Shortning the springs increases spring rate. Your opinion that you cannot cut 6" off the fork spring is wrong, you can. No coil bind, no damage.

For any serious dirt riding using fluid viscosity to control the dampening of the spring is far to old school but, is still considered ok for street use and does work for light off road work.

You have to use fluid visosity to control rebound damping. There are no rebound adjusters on these forks.

Remember: preload of a spring only effects the first inch of spring compression. Meaning it only helps suport your weight for the first inch of travel. You only want enough fork spring preload to have the forks ride at the right fork hight when you are riding the bike. A little more preload so the front end will ride a little higher in the whoops to get the timing right but, not more spring preload to help the fork from bottoming on a hit.

I did not sugest using preload to keep from bottoming out. I said use washers to set preload to 10mm.

Also, make sure you do not add to much fluid to the forks to reduce them from bottoming.

You must raise the oil level to keep from bottoming out, because the spring rate may still be to light, because he does not want to buy new springs.

  • BWB63

Posted October 22, 2007 - 06:20 AM

#36

Well, Mr. Captain Midnight, this is not about you. I am not directing all this to you or at you. I have setup many, many XR600 and "L's up for dirt. I didn't say you can't use fluid viscosity to control the spring rate, I said, it was old school and we do use Dextron for XR600 forks. In the end I was not fighting Captain Midnight. Don't get you cape in a wad.......:D

Reread it without it being about you and you might learn something.:crazy:

Some of you "L" guys are so uptight it is silly.

By the way 6" off the fork springs still sound like spring bind. I would have to messure the distance between the coils and add them together and find out what the limit is to what can be safely cut off. I have no problem being wrong on this. The point is do it right so there is no damage. You should not over fill your fork with fluid to stop them from bottoming! There is a limit to how much fluid you should put in the forks. This is a fact not my opinion, it is about pressure. For sure there is no rebound control on the XR650L and XR600 and this has been talked about over and over but, going to thick on the oil and not taking the forks apart to fix compression flow is going backwards. 5wt~7wt works ok if you actualy fix the compression flow. Like I said, I did not say you should not use heavier viscosity to control the spring but, that it was old school. I was gettting to the point that that there is a better way and I guess I should spell that out. As you go raise the viscosity you seriously slow down the compression rate and it is a good idea to fix that for any serious dirt riding. Just dumping higher viscosity fluid in the forks can make the bike not fun to ride.

  • martinfan30

Posted October 22, 2007 - 09:53 AM

#37

please tell me you talk about yourself in the third person!LOL!

  • Captain Midnight

Posted October 22, 2007 - 10:41 AM

#38

I didn't say you can't use fluid viscosity to control the spring rate, I said, it was old school and we do use Dextron for XR600 forks.

Dextron is to heavy.


By the way 6" off the fork springs still sound like spring bind. I would have to messure the distance between the coils and add them together and find out what the limit is to what can be safely cut off. I have no problem being wrong on this. The point is do it right so there is no damage.

I already have checked them for coil bind. It works fine. That is why I segested it.

You should not over fill your fork with fluid to stop them from bottoming! There is a limit to how much fluid you should put in the forks. This is a fact not my opinion, it is about pressure.

I did not recomend over filling the fork with oil. I said raise the level 2mm at a time, untill bottoming stops.

For sure there is no rebound control on the XR650L and XR600 and this has been talked about over and over but, going to thick on the oil and not taking the forks apart to fix compression flow is going backwards. 5wt~7wt works ok if you actualy fix the compression flow. Like I said, I did not say you should not use heavier viscosity to control the spring but, that it was old school. I was gettting to the point that that there is a better way and I guess I should spell that out. As you go raise the viscosity you seriously slow down the compression rate and it is a good idea to fix that for any serious dirt riding. Just dumping higher viscosity fluid in the forks can make the bike not fun to ride.

You really cannot read. My post said use 2 1/2 to 5 weight oil. Reread my post, and you will see, that it is accurate, effective, and low cost answer to Frank's question.

The end

  • BWB63

Posted October 23, 2007 - 07:13 PM

#39

Dextron is 7.5wt and has been used for years by XR's Only, Barnum, Jimmy Sones, and many, many Baja and desert racers for the XR600R but, the compression valving is changed and that is/was my point. The older forks it was nothing more then drilling the compression port larger.

As said, before what I wrote was not in responce to what you wrote. So, it did not matter what you wrote. Reading your post has no bearing on what I wrote........my point is to make sure someone cutting springs messure and do it right. Mr. Midnight you might want to read through the whole thread and find that I had something to say about no rebound control and viscosity before you thought I was talking only about your post.

I went out into the shop and grabbed a stock 20" spring.
Well, anyways there is .425 of an inch between each coil after preload and there are 31 spaces. This means a stock spring is good for 13.18" of travel. Now the XR650L claims to have 11.6" of fork travel. (of course with boot bind and where the forks are in the clamps, this is not always true) If you cut off 5" of spring you lose 9 spaces of .425" and that is if you cut the spring off only 5" so in the end you have a finish spring that is only 6" shorter, needing a 6" spacer. That would leave you with a spring that will bottom out in less then 9". So, for you that want to blindly follow what someone writes on this forum and not prove it first might just run the chance of really not being happy but, if you do not use the bike to the point of needing the last 2.5" of travel then all would be well. The most that should be cut off and still leave very little for error would be about 2.5" or no more then what it would take to have only remove enough spring that the finish lose is only 3" needing a 3" spacer. I have cut the springs on some of the XR650R bikes so they use a 2" spacer off this group and the Yahoo group and this makes the stock .43kg/mm spring to be a little more then .46kg/mm. Now if I grabbed the wrong stock spring it still won't be that far off. As always I could be way off and that is why you should always do the math and check for yourself. So, far I have found that if I take the time to search for the true answer frist, I do ok.

I see I need to go back to my rule of not writing anything I need to write "you" in. Or respond to post that have nothing but, "I" and "you" in what is written.

To respond to your last post:

[COLOR="Red"]"Dextron is to heavy"[/COLOR]

[COLOR="Blue"]Fact DEXRON®-III/MERCON® is blended to SAE 5W-20 viscosity depending on tempature and real close to the same Old Dexron @ about 7.5wt when use in forks as hydrolic fluid and it has been use for years in all the thumpers for many, many years. You should make the compression dampening so it can flow more. (this was stated close to the beginning of this thread)[/COLOR]

[COLOR="Red"]"I already have checked them for coil bind. It works fine. That is why I segested it."[/COLOR]

[COLOR="Blue"]I do not know how you checked for coil bind but; removing 33% of a spring that only has a little over 13" of travel and still not having spring bind is majic. Telling someone they are wrong before you do the right checks is not smart. [/COLOR]

[COLOR="Red"]"I did not recomend over filling the fork with oil. I said raise the level 2mm at a time, untill bottoming stops."[/COLOR]

[COLOR="Blue"]Never said, you did but, you sure in the heck didn't let anyone know that there is a limit to how much fluid that can be put in the forks. Fact that there is a limit and if you go past that limit you could blow your seals was the info. I was trying to give. [/COLOR]

This is the part that I do not understand....
[COLOR="Red"]
"You really cannot read. My post said use 2 1/2 to 5 weight oil. Reread my post, and you will see, that it is accurate, effective, and low cost answer to Frank's question."[/COLOR]

[COLOR="Blue"]Your post had nothing to do with my answer to doing it right and not just a compromise. I'm pretty sure that the stock recommended oil 'SS-7' is a 5 weight oil. Like always if for some reason I am wrong hat would be cool to learn that the stock XR650L doesn't come with 5wt fluid.[/COLOR]

  • XR680RR

Posted October 23, 2007 - 07:30 PM

#40

B-dub, sounds like someone really got under your skin here!:crazy:

I agree there is noway you can cut that much spring without spring bind...not with the numbers you are giving.

Dexron has been used by thousands forever.....but, without drilling out the hole in the bottom inside the forks of my XR600L in the 80's it was to slow compressing.

Let the guy go everyone can see what is going on here. You should know by now not to be a cross poster............this happens to often with some of the up tight "L" guys.





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