Was I supplied with an incorrectly sprung rear shock?

[chamelion]

Hi there,
 
Purchased a K-Tech Razor R rear shock from a well known company in Italy. I supplied them with the following information:
 
(Without gear)
106kg - Rider
59kg-72kg - Pillions
40kg luggage
 
And if I recall I specified 75% solo riding, 20% pillion and 5% solo+luggage/pillion+luggage
 
The spring that was supplied reads as a 100nm spring. From memory it says "150-100-**" (** = I can't remember)
 
I got my wife to hop on the back and the sag is huge. All most as much as the stock shock. Which defeats half of the purpose of the purchase in the first place if I'm to be honest. There is some preload available left that I can use, but not a lot.
 
Should I suck it up and buy a replacement spring? If so, what weight?
 
Thanks in advance.
 
ps: I've got some k-tech cartridges coming on tuesday too. I really do hope they've got something around the 1kg/mm in them and not 0.8 or something. >.<

[chamelion]

Anyone? I've been searching high and low online and I think I should have perhaps been supplied with a 115nm spring instead of 100nm.

[xlxr]

I weight 270 lbs in gear, and ride solo only. I have a 625 lb spring on Ohlins shock.  But there are reports for guys a little lighter than me with heavier spring.
 
Check rider sag, if you cannot get correct rider sag without shock topping out with bike weight only, your spring is too soft. You can also put a string around shock shaft to see how much travel it is using with different loads. If you bottom out the shock with max preload at max weight, you will need a heavier spring.
 
In order to get the shock spring to work with solo and two up weight, you generally need a spring on the heavy side for solo weight with minimum preload. Then be able to increase preload for two up weight, but still be on the soft side for two up weight.
 
You also have to consider dampening. Adding compression dampening can help compensate for a too weak spring rate. Too much high speed compression damping can also cause a stiff ride even through spring is too soft.