Fork Spring with different length

[fengluzon]

Hi.

I have a Yamaha WR250F 2005 and i bought for him a set of fork spring at the rate of 0.48KG and in length of 463mm.

Than i have replaced my forks with a YZ250F 2006 SSS fork and the spring rate is 0.44KG in length of 454mm.

Can i use one of the 0.48KG fork spring which is 8mm longer than the YZ fork spring, and insert it into the fork?

Can it damage the internal parts of the fork?

I need to get to 0.46KG.

Thank you very much.

 

 

[numroe]

Regarding possible damage: If the diameter of the coil is the same, then I suppose that question is about possible coil binding upon full compression when the spring wire lays down against itself. There is probably some formula for that, using the wire diameter and the number of coil winds per length, etc. Without the formula or the specs for the long spring, I'd look at the short and long springs on the bench and compare number of turns for the same distance. If the long spring has less turns per length, then it should safely compress enough.

In my experience with different coil springs and preloads in my SSS fork on my YZ250 and KX450F, I believe that 9mm of preload is a lot for that fork design, and probably too much if seeking best performance. In stock KYB SS fork setup they have zero preload or maybe some free play. Maybe someone else can confirm or deny that.

I found that the preload adjustment has a large effect on the feel from the fork near full extension when contacting the ground or rebounding. A big preload change might also require a specific rebound damping setting. The whole preload thing is however (in my amateur/enthusiast opinion) a personal preference setting, so you might find it's OK for you.

Probably someone sells shorter spring seats for the SSS 48mm fork. I guess that, since the SSS springs are I think the shortest main coil springs in any fork.

[mog]

You can machine down the spring seats

[fengluzon]

Thank you mog, but i'm not sure how to clear the ends of the spring which need to be cut.

I tried to find some info in the net, but couldn't find one.

I have tried to find 0.46KG fork spring in 454mm but it's not easy.

Thank you.

[mog]

No the spring seats , they are easy to cut , not the springs

[fengluzon]

No the spring seats , they are easy to cut , not the springs

Sorry, now i understand.

Thank you. I will try to do that.

Thank you mog.