Front fork springs ??

[css_elfers]

I did a search of the forum and really didn't find what I was looking for. My next project is the front suspension. I would like some input ,only serious replys or from people who know or have done this before. I'm not sending my forks off somewhere or looking to spend $400. I see some people have used xr400 springs and some people use regular spring. I weigh around 190 with all gear on. So I need to know what size springs, oil, spacers, ect. As usual thanks for all yawls help.

ELF

 

[rethnal]

.40 to.42 XR400 springs (you can use XR600 springs also) Spacers depend on the length of the springs, you will need anywhere from 3mm to 10mm of preload depending on how stiff you want them. They all are different in SOME way. Oil should be 5WT for good action, although some (including me) use Mobil 1 ATF. This should give you ballpark figures. This is the cheapest way you can go and get a good setup. Should only cost you around $40 to do if you shop smart.

 

[motorider200]

I'm running xr400 springs in my bike and love them. As far as the xr vs regular length spring goes which would you rather have in your forks spring or spacer? I made spacers out of pvc pipe i don't remember the exact length they were prabably around a 1/2".

 

[wanaride]

Look in the FAQ section, there is a link to a good description on how to change your fork springs and oil. The manual helps too, but I found the FAQ section to be particularly helpful. You don't need the "special tool" they mention in the manual...a combination wrench will work to hold the spring compressed. When you get it apart you will see what I mean.

I think my non-XR springs from Fredette were on the order of $60, plus about $10 for two quarts of Golden Spectro 5wt fork oil.

 

[Zerotact]

I have a set of XR forks springs sitting in my shelf. I went ahead and sent my bikes forks off to MX-tech, Jerimy did a great job, and everyone who rides my bike comments on how unlike a kdx it feels.

 

[rethnal]

You still got those things? :laugh:

 

[css_elfers]

Ok so I need spacers with the xr 400 springs, what about factory springs? Would I need spacers if I got bigger springs made for a kdx?

ELF

 

[billc]

XR400 spring info

I have XR400 springs from Ron Ayers in my KDX.Made pvc 11mm(7/16") spacers w/ Golden Spectro oil.Like it alot,best thing I have done to my bike.I searched this forum for all the info to do the job,it's all here if you look...

 

[rethnal]

No matter what springs you buy.... you will need spacers. An will more than likely have to make them. It's as easy as cutting PVC!

 

[css_elfers]

What size dia. pvc do i need? and whats the best size spring kdx and xr 400??

ELF

 

[wanaride]

When I asked Jeff Fredette about the preload spacers while installing new springs (non-XR), he said to not worry about it and go with the stock spacers.

Of course, maybe he sensed my newbie status and figured I better keep it simple...even so, my bike does handle better with the new stiffer springs.

 

[css_elfers]

Zerotact, you looking to sell the xr springs? might be cheaper if I go buy them with shipping and all. So if I go with a 42 size xr spring I can always losein it up some with the compresion setting if they are to tight right?

ELF

 

[matt-itude]

Im so glad you guys are talking about this. I just got my new springs for my 03 kdx. I bought 44s from race tech and have them half way installed. i stopped because it would appear that the factory under filled my forks atleast 10mm is this normal? i mesured it about three times and came up with just over 110mm each time. the manual says 85 to 100 does this sound right to everybody? they havent leaked a drop and my bike only has 500 miles on it. the race tech springs also came with a length of aluminum tube to cut spacers out of and pretty good instructions. as for the earlier question it would appear that this is the exact same kit used for a 400 xr by looking at the instructions.

 

[matt-itude]

the springs basically affect ride hight or sag. the adjustments as far as comp. and rebound would be ride as far as soft and hard. however as previously mentioned that ride hight affects stuff a fair amount at times. im hoping the new springs for me will keep the forks from packing down on me (im 225 ibs)
the problem is when i would pound down a rough road the forks would pack down then bottom on fairly small rocks and bumps. since kdxs havent got the rebound adj i have to go with thinner oil or stiffer springs to make it rebound quicker. since so far i am happy with the valving or firmness of the compression i dont want to change oils so i have to chainge springs. not to mention with the front sagged down with me on it it effects steering geometry.

 

[JasonWho]

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[JasonWho]

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[rethnal]

Durn good explaination there JW!

 

[matt-itude]

yeh the springs were a no brainer because i could stop on the trail and look down. my forks looked half way compressed just sitting there. then i would pull the front brake and up on the handle bars. guess what they were about half way compressed. as far as how much oil i lost i pulled the springs out very slowly as to not loose any because it was after the shop was closed and i had no 5w susp. oil. so im shure that wasnt helping my bottoming problem either.(i mean the low oil level) Im leaving in the next few to go get some oil.

 

[JasonWho]

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[css_elfers]

Thats what I'm talking about!! Jason thanks for your explanation, I like the in depth of your post. I used to ride alot when I was younger and my brother-in-law was sponsored by honda (3 wheelers) but have been outta the sport until about a year ago. I do try to do most of my own work and never before have I ever done anything with the front forks, so all the info I can get is extremely helpful. Maybe if I leave my phone number or vis-versa I could go over all my questions? Anyway thank you all for the impute, it has already expanded my understanding of the front forks 100%.

ELF

 

[rethnal]

JW... I forgot what schedule PVC to use, I think it was 40 but can't seem to remember. Also, wasn't it 1 1/2" ID pipe?

I just found it... Schedule 40 PVC and 1" :yeehaw:

 

[Rhodester]

I think you mean schedule 40 and 3/4 inch. 3/4 inch is almost 1 1/8 inch outside diameter.

 

[JasonWho]

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[rethnal]

When I say I found it... I mean I found a piece that I used and I don't (or haven't) done any plumbing recently! :) It is 1" I.D Schedule 40 PVC.

 

[matt-itude]

ok guys the tubbing i received with my springs is 1.25 inch aluminum marked 6016 t6. the factory spacers are about 1 .5 inches in diameter and heres something else i learned the aftermarket springs i got(racetech) are only 2mm longer free length than the factory ones and when i set the spacers up for the new ones to the specified 7mm of pre load the new spacers are almost 40mm shorter. so there was some 38mm of preload on the factory springs. oh and when i got really seriouse about the fork oil level i learned that when i was mesuring the oil in my earlier post i didnt allow the damper rod to drop all the way down so my messurments were bogus. with the rods down it apears to be right in the middle of the range (about 90mm). so make shure if your checking the oil level the damper rod is bottomed.