Front end too soft

[CAL-kawi]

Hello fellow kdxers,
It's been a while since I've posted here, but I'm trying to help another kdx rider set up his 97 220 with stronger fork springs. He really doesn't enjoy riding with the mushy front, not to mention it's downright dangerous on my local goat trails. They're tight, steep, with a lot of drops over big Douglas fir roots, and the risk of going over the bars on a steep boulder-strewn downhill is very real!
It's slow trail work, and he's not into the complexity of a KX front end, so at his 170 lbs I'm thinking .38 or .40 springs would suffice. Question is where to find them. Normally I order from Fortnine in Canada, or RMATV in the US. Neither have the .38 xr400 springs, wich I understand are discontinued, or the .40 post '98 xr400 springs. Bikebandit also shows no availability.
My local Honda shop said they couldn't get any xr400 springs anymore.
Has anyone successfully ordered Honda XR springs recently? And if so where?
Or are there any other options for a .40 kg springs that anyone knows of?

[kdxsully]

I use .44 springs from RaceTech. They have a calculator for your year bike and the weight of the rider to see what you need.

[CAL-kawi]

That sounds pretty stiff for woods work. How do they feel? Your riding weight must be higher than his?

[kdxsully]

I'm like 210 pounds without gear, so yeah.

[CAL-kawi]

There's quite a void between the stock .35 springs and the .44 that race tech still carries.

I'm seeing a place called Revzilla that shows availability of the '98 and later xr springs, not sure if they really have them. Anyone ever ordered from them?

[rungrandpa]

I used DRZ 350 springs that were .40. I don't remember the details, but you can double check the diameter and the length compared to KDX. I weigh 195 lbs with gear.
I bought from Ebay.

[CAL-kawi]

Thanks, hadn't considered the dr350. According to racetech stock forks are 43mm and rated at .38kg (although racetech seems to make errors sometimes on stock spring weights). So might work if I can find some. Do you recall roughly what you needed in the way of a spacer? In other words, was the length in the right ballpark?
Also, I'm guessing they feel better but still borderline on the soft side?

[kdxsully]

Thanks, hadn't considered the dr350. According to racetech stock forks are 43mm and rated at .38kg (although racetech seems to make errors sometimes on stock spring weights). So might work if I can find some. Do you recall roughly what you needed in the way of a spacer? In other words, was the length in the right ballpark?
Also, I'm guessing they feel better but still borderline on the soft side?

Gosh, I can't remember how I calculated my spacer. I think there's a formula somewhere or something.. I do remember that my new spacer was about half the length of the stock one. I'm still rebuilding my top end, so I haven't even gotten to break them in. They might respond a lot different later, but right now they feel pretty stiff. It feels uneven with my shock right now.

EDIT: also, my springs are the "alternative" ones. They listed two different spring "models" (?) for mine. I got mine on craigslist for a steal, full disclosure.

[KDXGarage]

From RMATVMC (DANG!!)

51401-KCY-761 SPRING, FR. FORK $63.95 $49.88 Not Shipping

1996 - 1997 XR400R is .38. 1998 - 2004 is .40.

Is your friend 170 in full riding gear with all extra parts, tools, water backpack, etc.? Does he have a bunch of guards on the bike (skid plate, pipe guard, fork / disc guard, etc.)?

I am thinking .38 is not enough even if he is 170 decked out.

Call Race Tech to ask about FRSP 3750K. It has a .40 spring, then another spring to make it .43 and another to make it .46, if memory serves me correctly. Ask if it will fit.

If not, I may have some .40's 3647 in the fork spring hoard.

[SS109]

I'm seeing a place called Revzilla that shows availability of the '98 and later xr springs, not sure if they really have them. Anyone ever ordered from them?

For furure reference, Revzilla is where I buy all my street gear. They are the RMATV of street bike parts and gear.

[CAL-kawi]

Thanks for all the replies everyone.
So, I don't recall much in the way of extras on his bike other than hand guards, and his PC pipe is lighter than the stocker. He's probably a little under 170, but in the 170-180 range geared up. .40 you think then? It's mostly slow technical trail work around here.
Interesting thought using multiple springs, so what you're saying is if I call race tech, they'll piece together whatever they have to come up with something to get us close?

[rungrandpa]

Thanks, hadn't considered the dr350. According to racetech stock forks are 43mm and rated at .38kg (although racetech seems to make errors sometimes on stock spring weights). So might work if I can find some. Do you recall roughly what you needed in the way of a spacer? In other words, was the length in the right ballpark?
Also, I'm guessing they feel better but still borderline on the soft side?

I experimented, ended up with 3" to 4" spacers. I swapped in KX 500 forks but at regular riding speeds the stock forks worked pretty good, especially for climbing rough hills. Fast desert work the KX forks took big hits better.

[KDXGarage]

Does he wear flip flops, tank top and no helmet or is he fully suited up? :-) My stuff weighs 15 pounds before chest / back protector. Another member on here has 26 pounds of stuff he wears.

Either way, I would not suggest .38. .40 should be better.

The 3750 kit comes with two normal springs and two sets of shorter springs. If one uses just the long springs, it is .40. If the softer extra spring is used, it is .43. If the stiffer extra spring is used, then it is .46.

"I DO NOT KNOW" if they will fit and work in 1989 - 1992 / 1995+ fork tubes. I don't see how they could market them for 1986 - 1988 43 mm tubes and they not fit the newer ones, but please call and ask their tech support. The length might not be enough.

Cannon Racecraft makes custom springs. They are over $170. Another member here bought some a couple of months ago. I helped him put them in. They were very nice looking.

[CAL-kawi]

Ha ha you nailed our riding gear! Well not quite, but most of our riding is right from my house, so we ride light. Also, when you're fighting your way up steep goat trails in first and second gear, you've got to keep cool, trials style. Point taken though, he's probably 180 geared up.
Have never experimented with a two spring setup, presumably the .40 with the short .43 would come in very close to the .40 overall spring rate.
Thanks for the options everyone, will try to line something up and will report back on results.

[KDXGarage]

I never ran the 3750 kit. With "just" the long spring, it might actually be .46, then the others soften the total rate. Be sure to call and ask them. I think I got that mixed up earlier.

[Slick_Nick]

I’ve got some 0.42’s laying around if you’re interested.

[Twinsig]

Nick, do you still have those 42s?

[Twinsig]

Updated here.
viewtopic.php?f=104&t=23762