Fork Springs

I plan on purchasing some fork springs for my offroad/ trails 06 YZ250. The MX tech spring calculator calls for .45kg springs for my weight (210 lbs. with all gear on). My question is that .45kg are hard to find and .46kg are the next size. How much would one size bigger in spring rate affect the suspension ride? Would it be to stiff for offroad/ trails?

I ride fast B harescramble level btw.

ok im no expert so dont take this too heart. but you have 2 options

1. reduce amount of oil you put in. that softens it up a bit

2. use the clickers on your forks (rebound, comp) and mess with em til you get the right feel.

you may also want to post in the suspension forum. youll get better results

.01 won't be that big of a difference. That's why springs come in .02 increments. If you really want .45, you can put a .44 in one leg and a .46 in the other.

Put in .44kg springs and see where your static and rider sag is. Better yet before you buy any springs, see where your sag numbers are. I bet money that your stock springs are fine for offroad. If your static sag is between 35mm & 45mm and rider sag is 75-80mm then you don't need springs.


I'll check my static & rider sag and see what I come up with. I'll post them later. I was thinking a little stiffer spring would help keep the front higher up and be more plush, but again it could go the other way.

A .46kg/mm spring is about 2.2% stiffer than the .45kg/mm spring.

2.2% of your riding weight is about 4.6lbs.

The water in a 70oz Camel back weighs about 4.6lbs.

Would you want to change springs if you decided to wear or not wear a Camel Back?

I wouldn't worry about it!



The stock spring rate is .43, so I'm with Dwight, I don't think going to a .44 will offer much change. And the stock spring may work for you. I think one of the manufactures makes odd number rates, but I can't remember which one. So, you may find a .45. I have the same bike and I weigh about 205 lbs in the bare. I think I am about 230-235 lbs in gear with full camel bak and tools. I also have an over size tank. I picked up some .47 on eb** from a yz450. I haven't installed them yet, but I'm hoping the .47 will be the ticket for me.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now