I have now fitted a 800lb spring ( was 550lb) on my 200mm i2i shock and I makes it very nearly acceptable for my needs ( but not quite
) but I think it will still be far to weak for any form of road riding. So now Im on plan C
the stroke on my shock is around 3cm'ish and im using about 2cm'ish so I think im going to look for a 165mm i2i decent shock and move the shock mounting points to keep the same ride height and Im hopeing that the 2cm'ish travel will be enough without bottoming out. It is very easy to get springs for this length of shock upto 1200lb buy buying a very cheap tacky shock just for the spring. I am running out of plans now but I do have one more plan D which is to have 2 shocks a longer stroke ( with the 800lb spring ) in parallel with a shorter one with a stiffer spring but to have some form of free travel on the shorter one. This may be perfect for my use as it will make the suspension very tunable for what I want and it will still be lighter than a proper motorcycle mono shock.
Edit: I have been looking for a oil over coil short ( 165mm ) shock and now im not totally sure if the the cheapo shock springs will fit over the shock body.. I need to do a bit of reasearch before I decide
Have anyone reading this got a coil over oil 165mm i2i shock that can give me the shock body dia from, this would be a great help.