What spring do I need?

[Banditpowdercoat]

I have a 98 EC250. Prev owner was heavy kid. He had a 6.4kg-m spring. But also kept the 50Nm spring (5.09Kg-m?) which I have in now. But it's too soft. I am around 200Lbs in gear. I have about 16mm preload to get 115mm sag with me on bike in shorts, 175lbs. The spring on it now is ohlins 596-09/50-088 57mm inner diameter. Just I dont have a clue what Kg new spring to get? Will a 5.4 work? Or should it be 5.6, 5.2? Rear is harsh over logs etc, yet bottoms on large dips like the big waterbars we have here.

Little more info. 20mm preload, on the 50Nm spring nets 115 sag with me, 175Lbs on it, no gear, and 35mm static sag. Those numbers seem close to what I read is good. But the 20mm preload is double what I read on here, the GMP method of 10mm or so.

[Jacob 'Berg]

Too much pre-load on the spring is not good. The shock will not be as compliant as it requires more energy to initially compress the spring and will require more rebound damping as it is storing more energy.

I would guess that you will need a 5.4 or 5.6. Someone more knowledgeable than I may be able to determine what spring you need based on the pre-load and your sag numbers.

[nknudsen]

5.2 will be too light. On my 2000 EC250 I run a 5.4 spring and I'm 190 lbs. I would say a 5.4 would still be good for you.