Unfortunately it's hard to recommend a specific weight I'm using a 40 lbs or 50 lbs at the moment can't remember, different variators and setups/belts require a bit of tuning weight wise. If you run a spring in conjunction with a damper, I suggest going with a lighter damper weight and use the spring for the tension and the damper, to well dampen. I've noticed the ER3 has tendency to like a spring and a damper and with a variotop I was able to just run the damper only, it's really strange. I just recently put a modified ER3 back on my bike and completed a fair amount of other work and will soon be switching from just a damper over to a spring and damper. Hopefully that helps with making decisions.