Heavy Rider

[ian1987]

I weigh about 18 stone (115kg).

I notice my 2008 EC300 is a bit soft at the rear. Is it as simple as fitting a heavier spring?

If so which grade do I need?

[Anders]

Originally Posted by ian1987

I weigh about 18 stone (115kg).

I notice my 2008 EC300 is a bit soft at the rear. Is it as simple as fitting a heavier spring?

If so which grade do I need?

A heavier spring is certainly needed. You might also experience a need for higher rebound damping when the heavier spring is used.

As to the spring rate, I would guess somewhere above 6kg/mm.
A few days back we had this thread.
But spring rates used in the 2012 and later differ from the rates used i 2011 and earlier due to a difference in the linkage.

Please check the rate with someone more knwledgeable than me. There are some spring calculators around, e.g. Racetech. You should also do the same at the front (change the springs for heavier ones).

[Zman]

You need to also consider what type of riding you will be doing. If you are a trail rider go for a softer spring and stiffer if you are a racer.
Regardless the stock springs are too soft for your weight. From my experience the racetech calculator tends to recommend stiffer springs.