2006 CRF 450X Stock Fork Spring Rate

[JackAttack]

I am finding different #'s in my search for what fork springs come stock on 2006 CRF450X.

 

I believe they are .47, can anyone confirm.

 

Also, I need to go stiffer if anyone has an inexpensive place to source them.

 

Thanks

[CRF DOC]

Some references say .45 others say .47.

I've tested them and they are .47 kg/mm.

[5kcstq]

I had to go down in stiffness for my weight and sourced springs from a 250.  You can do the same and source Showa springs from any of the other bikes that use that 47mm Showa fork.  Check the R models for a stock size that's right for your weight and then source from ebay if you really want to go cheap. Factory Connection, RaceTech etc. all have charts that you can use to look up what fork and what weight springs are stock.

 

Hope that helps.

[JackAttack]

Race Tech says stock is .45

 

Eibach says stock is .46

 

Factory connection says stock is .47

 

I did not get a manual with the bike, I wonder what it says?

[FORMA MOTO]

Those are all correct, depending on what country and what year.

 

Assume .47

[MartyMOOSE]

I was told 0.45 mine measured 0.47 I also had a set of race tech 0.47's that are 10mm shorter than the std X springs so I fitted them ?  Don't forget the ICS springs.

 

 

MM

 

BTW the rear measures 5.35 not 5.5...........................

[MrRong]

Manual says .47 stock 2006 crf450x. Swapped to eibach springs .50 and 5.9

[450XJimDirt]

Occasionally i find a decent priced used pair on EBay for under $100 and sometimes as low as $65 for the pair  , if they happen to be Race Tech you will need 10mm of washers to get the correct free sag because the Race Tech springs are shorter than stock , you can get them from Race Tech (they will sell you 4 washers , 2 for each fork), they are basically real thick flat washers , they just have to be the same outer and inner diameter as the spring itself is  , i believe some Eibach springs are also shorter , but the fork spring washers will make up any difference

[MartyMOOSE]

No washers needed the x runs too much internal preload stock.

[450XJimDirt]

The Aus X might but the U.S. X definitely has longer fork springs than the Race Tech springs , i had to use 10mm of washers , and its what Race Tech recommends for the X

[Xccelerate]

As long as we're on this subject... I need to lower my '05 crf450x by at least an inch. In addition the ride is so stiff it beats the crap outta me when I hit any sort of rocky section. Also the bike refuses to go slow without bogging out even when geared down.

Since I weigh in at 180lbs and stock fork spring rate in .47kg, how much softer should I go to get a nice plush ride in rocky terrain while plodding along in first gear at 15MPH?.

[bajabinder]

On 5/7/2018 at 10:09 PM, Xccelerate said:

As long as we're on this subject... I need to lower my '05 crf450x by at least an inch. In addition the ride is so stiff it beats the crap outta me when I hit any sort of rocky section. Also the bike refuses to go slow without bogging out even when geared down.

Since I weigh in at 180lbs and stock fork spring rate in .47kg, how much softer should I go to get a nice plush ride in rocky terrain while plodding along in first gear at 15MPH?.

Have you adjusted the clickers yet?  Is your sag correct? If not, then adjust your sag first. Next: turn the clickers all the way in (don’t mess with the small high speed clicker at the top of the shock...only adjust the slow speed clickers) counting the clicks, and write those numbers down...now you can return to your current setting later if desired. These will be your stiffest suspension settings. Next: back all the clickers out as far as possible. This will be the suspensions softest settings. Take a ride with the softest settings, and FEEL how the suspension acts. Next: crank all the clickers back in all the way, and take another ride to FEEL how the suspension acts. Now you know how the range of adjustments FEEL. At this point, I like to put the clickers at their mid-settings, go for a ride, and adjust to suit my needs. There’s a ton of more detailed info on how to adjust the clickers, but this gets you started. A couple things to remember: 

if you’re not bottoming out, then soften compression clickers until you do. Then tighten clickers until you bottom out infrequently. 

If the bike is bouncing back up after suspension compression, then tighten rebound clickers until the bouncing goes away.

remember your goal here is to be “plush”, so the softest settings without unwanted bottoming or bounce/kickback is the goal. 

This should help you maximize the suspension you already have. If you can’t reach your goal, then springs and/or valving will need to be changed. Again, this is very general info, and will get you started. There’s a lot more fine tuning info available. “Softer” springs don’t guaranty a “plush” ride. At 180lbs, I’d guess you can make the stock springs work for you...if you take the time to tune your clickers. 

[Xccelerate]

Thank you Baja... for the key info you've posted here.

Yes I had the sag set properly. In fact the same suspension tech that revalved my forks for a softer ride (helped a little), also set the sag for me. I had the shock backed way out to lower the seat but got schooled on that and he jacked it back up to adjust the sag. Now it steers better but I am not a all comfortable with my head in the clouds and unable to do little more than touch tiptoes of heavy boots at a stop.

It has taken all the fun outta riding as I'm so damn busy making sure I place the front wheel where need be so as to not risk a stall in the slow rocky terrain we encounter everywhere here in central AZ.  Sucks cuz I cant put a foot down in a turn and a stall means I'm going down for lack of footing... ridiculous trying to ride like that.

I will try doing what you suggest with the clickers but the fact remains... if and when I stop anywhere for whatever reason the ground is still way outta reach unless I jump over to one side and pray for good footing. And doing that pulls my other foot off the peg so there's no getting back aboard and I'm stuck. No fun and I'm seeing no way out other than to lower it.

Edited May 10, 2018 by Xccelerate

[CRF DOC]

14 hours ago, Xccelerate said:

Thank you Baja... for the key info you've posted here.

Yes I had the sag set properly. In fact the same suspension tech that revalved my forks for a softer ride (helped a little), also set the sag for me. I had the shock backed way out to lower the seat but got schooled on that and he jacked it back up to adjust the sag. Now it steers better but I am not a all comfortable with my head in the clouds and unable to do little more than touch tiptoes of heavy boots at a stop.

It has taken all the fun outta riding as I'm so damn busy making sure I place the front wheel where need be so as to not risk a stall in the slow rocky terrain we encounter everywhere here in central AZ.  Sucks cuz I cant put a foot down in a turn and a stall means I'm going down for lack of footing... ridiculous trying to ride like that.

I will try doing what you suggest with the clickers but the fact remains... if and when I stop anywhere for whatever reason the ground is still way outta reach unless I jump over to one side and pray for good footing. And doing that pulls my other foot off the peg so there's no getting back aboard and I'm stuck. No fun and I'm seeing no way out other than to lower it.

Why not send in your suspenders to a suspension guy to have them revalved and lowered?? When done right it's all internal and can be lowered up to about 3 1/2"... adds a ton to your confidence...

[bajabinder]

Or...shave the seat and run a lower profile rear tire. The DOC is of course, suggesting the proper way to lower it. 

[Sumoman]

im 5’9” (250# tho) and i was considering lowering my suspension but instead bought Seat Concepts low version (which is 1” lower), which with my riding boots gave me enough to not shorten my suspension. so far it hasnt been a problem

*side note- i did have my suspension completely resprung and revalved and geezus what a difference on the trail - worth every bit of the $800

edit: i kept the stock ride height to maintain full ground clearance

Edited May 10, 2018 by Sumoman

[Xccelerate]

On 5/9/2014 at 7:27 PM, 450XJimDirt said:

Occasionally i find a decent priced used pair on EBay for under $100 and sometimes as low as $65 for the pair  , if they happen to be Race Tech you will need 10mm of washers to get the correct free sag because the Race Tech springs are shorter than stock , you can get them from Race Tech (they will sell you 4 washers , 2 for each fork), they are basically real thick flat washers , they just have to be the same outer and inner diameter as the spring itself is  , i believe some Eibach springs are also shorter , but the fork spring washers will make up any difference

So are you telling me that the Race Tech shocks will lower my bike? ... YES!

 

[mlatour]

No matter if they are physically a shorter, all springs require some preload.

If the forks were designed for a minimum of 5mm of preload,

having 10mm shorter springs will rattle and bind each time the forks unload and go to full extension.

Not enough spring preload, especially on a heavy 4-stroke will make the forks dive while braking or deceleration (engine braking).

 

The risks of a shorter shock spring is going into coil bind before the end of the stroke.

Race sag / free sag numbers (preload) must also be within the ballpark no matter the spring's length.

 

Shorter suspension is achieved by spacers that limit full extension of travel,

shorter springs (or relocated perches) are then used to match the new range of travel.

Edited May 13, 2018 by mlatour

[Sumoman]

have you considered the kouba lowering link? i think i remember them coming in 2 or 3 different sizes. they do the trick but the guy who did my suspension recommended not to go with a kouba unless necessary. he mentioned something along the lines of it messing with the overall geometry of the bike or something to that effect. 

Edited May 13, 2018 by Sumoman

[mlatour]

Myself have a Kouba CRF2 link on my CRF250X (about 1/2" drop)

there is a CRF3 which lowers the rear even more but from experience on my YZ (Yamalink)

that's too drastic and really affects geometry and especially the swingarm/linkage/shock leverage ratio.

 

1/2" drop at rear (Kouba link)

1/2" drop at the front (from sliding the forks up in the clamps)

 and a 1" or so lower seat foam (Durelle)

makes for a noticeable drop in seat height while keeping the steering geometry and suspension travel close to stock specs.

Edited May 13, 2018 by mlatour