KDXRIDER.NET

My forks are supposedly off a '99. Inda's are the '03s.

I guess the bladder is not your conventional bladder.... simply a trapped area from what I get out of the posts on TT.

He's got the 2003 KX500. He seems to think that Ma Kaw kept up with suspension mods but I'm convinced he doesn't know for sure. Nor does he seem to care. When I've talked to him about this thread, he can't figure out what the deal is. He's owned the KDX and he's modified his to USD forks. (Not KX but YZ's!!!!) Hands down, without any arguement, there is a heap of improvement. He also just keeps reminding me, I don't crash (as much) and I'm much faster than before. (Shut up CC. I don't do well in new terrain and under pressure!)

Unfortunately, the only thing that changed about KX500 forks from 1997 to 2004 was the color. (source = buykawasaki.com)

As your personal experience shows, you are much faster / safer with the current forks. Those seem to be great reasons. I can tell from your previous posts that you love them.

I bet your friend never posted a message on the internet asking about should he drop one tooth on the front sprocket of his KX500.

Got a KDX stem on the way...from FRP. $50. Comes with the clip. Also got a bottom bearing.

I'll be able to swap the whole mess back and forth. Probably won't ever do that...but I could if'n I wanted to!

Now...about that axle and spacers.....

My KX forks are supposed to be off a '99 250. They have no bladders. Don't know if they USED to or not...they don't have the OEM KX base valve in 'em either.

Tried to measure the springs. I got 'around' 21#/in on my dandy battroom scale. Difference between .38s/.40s on that scale is just over one #/in, so it's a bit less than exact. They are straight-rate springs. No markings on them that I could see. OEM springs are progressive.

I just got a set of RaceTech .38s (whoever makes them anyway) off ebay.

Almost ready to go!

You will probably want to stiffen up that spring rate. I'm running .42's Doug's going to get stiffer Race Techs for his forks. He will be having the stock 2003 KX500 springs. Look into it and see if they are useful to you. He's probably going to just toss 'em.

I suppose the fact that a .38 spring in the OEM KDX fork is perfect doesn't mean anything on a KX fork on the same bike, ridden in the same way?

Yeah...I understand that other things effect fork action...like a too soft spring can be too harsh cuz you're in the hi-speed stack all the time (if you're setup that way).

But a .38 in one fork is different than a .38 in another fork?

Probably no reason to think there is any relationship between the two. They ARE completely different forks and all that.........

The spring holds up the weight of the bike and rider mostly, so I would say that the same rate springs on the same bike, just different forks, would be a good thing. Now, if you had .38 springs in a KDX and took those KDX forks to a lighter KX125, for example, then THAT would make a difference since the combined weight of rider and bike went down.

Yeah...I understand that other things effect fork action...like a too soft spring can be too harsh cuz you're in the hi-speed stack all the time (if you're setup that way).

Springs are position sensitive. Valving is speed sensitive.
Springs are position sensitive. Valving is speed sensitive.
Springs are position sensitive. Valving is speed sensitive.
Springs are position sensitive. Valving is speed sensitive.
Springs are position sensitive. Valving is speed sensitive.

As stated above, a .38 rate spring in different forks on the same bike should be similar. Now, if you put those .38's in skipro3's Voyager, THEN you would have major problems! Race Tech shows .50 springs as stock.

A further example is the OEM Honda XR springs. The reason they come stock with .38's or .40's is because it is a heavy bike.

I have faith that you will try more than one spring rate before it is all over.

Re: speed sensitive
Yes, they are (it is?)...and the 'speed' of any valve is going to increase with an underrated spring in use.

It's a not uncommon mistake suspension-wise to think you need a lighter (lower rated) spring when if fact what you need is a stiffer (higher rated) spring due to:

...like a too soft spring can be too harsh cuz you're in the hi-speed stack all the time (if you're setup that way).

'Speed' of course in this case being used to denote fork movement, not the bike.

Even a stiff spring won't compensate for a log, rut, rock, etc. Too stiff / too soft will show up more in the "rides too low / too high or understeers / oversteers" type of complaints. Any high speed hit is going to compress all those flexy flier low-speed shims and get on down to the high-speed shims. They all work as a team, so its not like only set works at a time or can be adjusted out specifically without having an effect on the whole stack.

That's right... if it can blow by the low speed shims..it is going to be harsh once it hits the high speed. Making someone think the spring is too heavy... but if the spring is too light to take any of the blow... It gets slowed down by the HS shims instead. OUCH!
Fortunately it is easy to check for this by the Ty-Rap around the fork method to see how far it is getting. (My seal Savers have the same effect)

I don't think the KDX forks have this complicated of a setup and is easy to tell the spring is too light by fork diving and bottoming (it just is). The KX forks on the other hand will hold up until hit hard if the springs are within -.4 of being right....