KTM Shock spring question

[Yamadad]

I have a 01 400 SX with a stock shock spring. I know they come in different spring weights. I suspect it is the heaviest, but can't find any markings on the spring. The coils are about 13mm thick.

Can anyone tell me which weight spring I've got based on this measurement?

(The reason I ask is I can't get more than 85 mm of sag due to the heavy spring.)

 

[cliwar]

I don't think you can tell the spring rate from the wire diameter used to make the spring. The spring rate has more to do with the differences in the heat treatment process applied during manufacture.

If you check you user manual, It may well tell you what rider weight the stock bike is set up for and what spring is fitted as standard. If your weight is similar to the "stock rider" weight and you can't get enough sag, you probably have a heavier than stock spring fitted. In which case, you want to buy a new spring similar to the one fitted as standard.

Hope this helps.

 

[elf]

There are dozens of spring rates available for ktms, Yours is way too stiff. With the right spring for your weight you can get 150mm sag easy. click on the mx-tech i-con on the side of this page and use the spring generator to find out what spring you need for your weight and riding conditions.

I know for a straight rate spring there is a formula to find the rate, but yours is a progressive.
You can also send the spring to mx-tech and they can test it to see what the spring rate is.