CC - important springs Q

[limitless]

Ok I figure this would be the place to ask. I bought what was supposed to be some XR400 springs from a drn member (hondaxrguy) and figured they were the right springs. I haven't had time to mess with them so they've just been sitting around. I went to install them today and everything was going good until I decided to measure them! They were 470mm and not the 530mm I had expected!?

The manual says the stock springs measure 457mm & you say they measure 470mm right?! who's right? The springs that I removed were 470mm, but I dont know if those are stocker's or what. I'm assuming they are. Anyways, so now I have no clue if the spring is stiffer or if it is an aftermarket XR spring or an XR250 spring or what the hell is goin' on. Did this guy screw me over or what is goin' on?

**edit - Just to clear up I do not want to think this guy would screw me over. I think it is very possible that it was an honest mistake on his part, he does not seem to be the type who would purposly send the wrong stuff!! The main goal is to find out what the springs are (IE XR250).

 

[RTL]

I'd PM him and ask if maybe he sent the wrong springs...

 

[limitless]

I did not mean to flame him, he seems to be a good guy. He probably just sent the wrong springs. I know they are not stock XR400 springs (by their length). I have sent him a PM, I just want to find out if they are from an XR250 or some other bike that uses 470mm springs (IE a KX250?)

 

[KnoxKDX]

Hmmm...that is odd...what's even stranger is that the set of 400's I have are just over 20" or 508mm. They came off of a '97 and were only used for a month before the original owner changed them out. But I wonder why our numbers don't jive?

 

[limitless]

I'm not sure, but I wil go re-check my measurements (AGAIN!)

 

[CaptainObvious]

They may be out of an XR400, but are they the OEM springs out of a 400?

 

[Hondaxrguy]

Limitless, I just got your PM. I'm just as puzzled as you are. They defenatly aren't springs for my KX250. They came with the 98XR400 I bought from a friend long before I got my KX. He said they were the stock springs (in the replacement springs box). I didn't have any reason to question him about the springs as he also gave me the stock filter, plastic, shock spring, etc..... Are you sure your year KDX will work with the XR springs?

Like I said in the PM, If I made an error, I'm more than willing to refund your money. I had no intention of ripping you off one bit.

Jeremy

 

[limitless]

I don't think you would try and rip me off, after all you sent the springs before you had the money..... anyway, yes I know they will fit in my year KDX & they will fit no problem, it is the length that has me puzzled... I would just deduce it to the previous owner of my bike installing XR400 springs if it werent for all the people on here saying they are longer than 500mm. I'm not all that worried about the money. hopefully they are stiffer than the stockers, but I'll let you know what's up when I get em' tested and check out an XR400 manual.

 

[dirt bike dave]

Honda owner's manuals are usually pretty good. My CR manual has an identification chart for how to tell the stock Honda spring from the optional softer and stiffer Honda springs. Identification is based on how many coils with no gap are at each end of the spring Perhaps someone with an XR manual can check to see if there is a similar chart to help identify the springs.

 

[limitless]

I'm going to a dealer to check one of there manuals.

 

[canyncarvr]

Springs out of my kdx were 470. Springs I put in that were for an '00 XR400R measured 532.

I'm looking (see it? It's right over there <--) at an oem spring out of another '00 kdx that is 470mm.

I was just talking to a tuner today that referenced the 'longer' XR springs as being his choice for the kdx....he referred to them as 'five-thirty-something' in length.

Seems something is amiss. Something got mixed up somewhere.

Good luck!

The length (longer) of the spring is part of what makes it 'work'. I'd be looking for the 530s.

 

[limitless]

Yeah, I just hate to lose the money even though its not much. I dont want to go through the hassle and time it takes to send em' back, get the money, find new ones, talk to the person, send the money, get em shipped blah blah blah! O'well all that will have to wait awhile I guess.

 

[GreenPeace]

Good news.
The local dealer just told me the XR400 springs I ordered from Japan arrived.
I will install them before the **** crows. Bear with me, I'm so excited and you are the only guys I can share with.

 

[canyncarvr]

Put this under the heading of 'FWIW' on these springs.....

I talked to a local (kinda..within 100 miles) tuner yesterday. This guy has quite a reputation around here. He makes stuff work....real good. I've ridden one of his reworked bikes. It was quite amazing.

I got the XR spring tip from him a couple years ago.

He said the preload on the XR spring in the kdx doesn't have to be much..along the line of 2mm.

I spent some quality time with my bike last night coming up with some PVC spacers for such a preload. Making a .128" (3.25mm) spacer that's square isn't real quick.

Keep your preload pretty low.

BTW, his oil level rec is 110mm on the kdx.

 

[limitless]

What should the preload be with the 470mm spring? Will 9mm make a big difference? mine is at 19mm with the stock spacer

 

[Zerotact]

I have heard of oil levels from 100mm to 120mm on the kdx

 

[limitless]

I set mine at 85mm

 

[canyncarvr]

Recheck your figures on the 19mm preload with a 470mm spring. I'm not looking at what you have, but unless your stock spacers have already been cut, there's quite a bit more preload than 19mm in the oem configuration.

In any case, yes 9mm is a big change. The more you ride the more you come to expect from your suspension, the more finely tuned you will become to what it does, what effect changes have.

The tuner mentioned previous....he has adjustable preloaders on his ktm. He changes them from 1mm (desert) to 2mm (woods). Because it matters to him.

I've changed a shock clicker one click on my riding buddy's bike when he wasn't looking once. He knew immediately that something was different, and he knew what it was, too!

I had been having some problems with my shock that I couldn't click out.
When the mentioned tuner rebuilt my shock, he looked at the shim stack and said, 'Your bike is doing <1>, <2>, and <3>.' Not a question. A statement.

And what he said was an exact list of the problems I'd been having.

The point is...while 9mm preload change may not seem to be much, or may not matter to you, believe me. It matters.

If it doesn't matter to YOU, that's another issue.

When I asked this tuner about my current fork troubles, he asked what the preload was. I told him (6mm). He said...'That will make your front end <1>, <2> and <3> It needs to be about 2mm.'

Uh......yep. He nailed it again.

He's a pretty much smug smart-arsed cocky sunnuva gun. Just so happens he also knows what he's talking about. There's a name for that....something like 'Moderator's Disease' ? ;)

BTW...is there some point to the 85mm level? Making up for an underrated spring?

 

[limitless]

I have no idea what to set it at so i'm just starting there. I don't know what else to do but just start somewhere and go from there to find out what suits me best.

As far as the preload.... how do you check the preload.... heres what I did

1. measure the springs sitting in the tube (bottom of fork tube to top of spring
2. install the spacer.
3. measure form bottom of fork tube to the top of the spring
4. subtract 1 from 2

that equals 19 mm

Is this not correct? I'm not real sure but that seems right. should I goto 2mm or start with say 8mm? should I set the oil level closer to 100 or start at 85?

 

[canyncarvr]

Figuring preload doesn't involve measuring the spring at any point. But that 'figuring' part is usually intended to find out how much spacer you need to make.

With the spring in the fork (no spacer) and the cap installed on the piston rod (threaded all the way down), measure the distance (gap) between the top of the spring and the bottom of the cap with the fork fully extended.

If that gap/space (example) is 10mm, then you would need a spacer 29mm long to get a 19mm preload. You are compressing the spring 19mm.

Your method makes sense to me, though.

The 2mm preload figure is for a specific spring with a specific fork setup. It's less than is normally used.

re: '...start somewhere and go from there.'

Not a bad plan. Consideration of some of the 'norms' may save you some trial and error time. 19mm preload is on the high side. So is the 85mm oil level (given correct spring rates for the forks to start with).

Sure...start with 8mm preload. Lose some oil. Probably a good idea to do one thing at a time.

Good luck!


***edit***
BTW..doing some guessing, I get this:

My spring @ 532mm gives me 3.5mm gap. A 62mm shorter spring (470mm) along with an oem spacer of 87mm (a guess..about 3.5" I think the tubes are) would give you a 21.5mm preload with the shorter spring and the oem tube.

So, your 19mm measurement is probably good. That 3.5" part seems a bit on the short side though.........

 

[limitless]

cool, Im gonna ride tomorrow and see how everthything goes and do some experimenting with it. Thanks for all the great info.

 

[canyncarvr]

BTW (because I brought it up earlier).......

The change in handling going from 8mm to 2mm preload was minimal. Changing the clickers from 8 to 5 made a huge difference! I've had the clickers in and out before trying to sort out the front-end, so maybe it was a combination of the two adjustments that had a positive result.

No more 'crabbing' in downhill ruts, sidehill tracks greatly reduced if not eliminated the 'white knuckle' effect, on uphills I can much more easily pick whatever track I want. It used to be difficult to change.

A huge difference in handling for a few clicks of a screw!

Good luck with your scoot.

 

[limitless]

I went to KY for a ride and the forks were STIFF. There were alot of sharp ditches they look like V everytime I would hit the bottom it felt terrible the forks would move only a couple of inches. It wore me out quick. I adjusted the clickers down to 4 from like 12 (with help from CAL) and that helped a lot.
It still feels a bit rough, so I think removing some oil is nesecary (SP). There is a race next weekend though, so I think I'll just back the clickers out to like 1 or so until I have a chance to remove some oil. How much oil should I take out? I dont have a way to measure it when the forks are on the bike so I was thinking of taking out 5cc's each. Can I do this without taking the forks off? I think I can but Ill have to take off the bars....What a pain.

thanks for the help

 

[limitless]

BTW how many MM is 5 cc's?

 

[Zerotact]

5cc = 25mm2