True spring rates



4 replies to this topic
  • FOX426

Posted February 19, 2002 - 10:36 PM

#1

I belive the spring rate on my stock 00426 forks to be 46kg; however, researching several suspension sites I have seen three different rates listed as stock. 46,47,48. Of course all reccommend different rates for my weight of 225lbs. Same story for shock spring. Any experts out there with the absolute facts and reccomendations? Note: race mx/225lbs/intermediate to novice level,ie: big doubles, no triples. :)

  • 98yz

Posted February 19, 2002 - 10:59 PM

#2

FOX, I would use the rates off the GP-Racing Webiste. They built the suspension on my 01 426, and it seems to be spot on. Good Luck


www.gp-racing.com

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  • DaveJ

Posted February 19, 2002 - 01:54 PM

#3

FOX426,

First of all, if your bike was built for use in Canada or the U.S., it shipped with .46 front springs and 5.4 rear. Non-progressive.

The "ideal" spring is conditional to bike weight, rider weight, and application.

Each suspension shop and rider is usually bias towards a type of application. Some do nothing but Supercross configurations, others do nothing but enduro or woods.

This is why the question of what you plan on doing with the bike is so important.

And as you may already know, many race teams are prepared to switch spring rates in accordance with the terrain they are riding. So it certainly wont hurt to have some options if you take this sport the least bit seriously.

If you want to keep it simple, determine what you do and don't like about your current ride and share that with the board. There are many here that can help determine what they did to resolve issues by configuring a sharper and more controllable machine. You'll also find that the valving plays a bigger part in the picture than you first imagined.

But at 225lbs, unless you’re using the bike to get groceries, you'll most likely need a stronger spring than what's currently in there.

Perhaps you could share some further info with us.

DaveJ

  • FOX426

Posted February 19, 2002 - 04:17 PM

#4

Thanks for replies. I race outdoor mx only. Overall the bike handles pretty well, no real complaints diving in turns etc. My biggest complaint is as I am getting faster and going bigger I have started to bottom the forks. The entire bike does wallow on flat landings. The whoops are a little harder now to stay up on top of now that I can hit them and notjust creep.Once again overall I can live with everthing except the big bottoming and wallowing. I have raised the fork oil by 5cc and am going to add 5 more, forks are flush in clamps, rear sag set at 95mm. Ihope this is the information you guys are looking for. I appreciate the input.

  • DaveJ

Posted February 19, 2002 - 10:27 PM

#5

FOX426,

This is a bit tricky.

Springs hold the bike up. Valving controls the rate at which a load is applied to the springs, and the rate at which the energy stored in a spring is released.

Therefore a bike that bottoms and wallows could be in need of either spring or hydraulic changes, or both.

How does one know the difference?

Springs, front and rear, should generally hold the bike and rider up within 25 to 30% of total travel. Since you have a limit on how much pre-load can be applied in the front, you may soon have your answer.

Valving controls wheel oscillation. In other words, if a two inch bump takes up three inches of travel, you have problems.

If you watch the AMA supercross guys on TV, you'll notice they have very little wheel movement, but not much body and bike movement. Plush but firm.

If you're not sure what your bike is doing, you may want to have someone video tape you.

To add to this madness, I'm a little concerned about these types of complaints due to the number of times I have lost compression control on my forks. Poor oil performance and mid-valve failures are usually the cause.

This makes me wonder how many other riders are out there wallowing and bottoming out with the assumption that all is well.

Perhaps if you're not intrigue by doing this yourself, you may want to seek professional assistance. Ask around for suspension shop recommendations.

Hope this helps.

DaveJ





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