I have a spring for a 21 which I was informed is HRC.
There are no markings that are obvious to me. Without taking the original shock off the bike and the spring from the shock to compare; is there a way to tell?
I was told maybe the diameter of the steel could be different. I realise there are 2 or 3 different spring weights; to tell the difference?
If any body has any info, I would appreciate it. Just gathering info at the moment; miles away from my bikes.

On a different subject, I just bought a complete HRC jet kit for a 21. I went all tingly. Is this normal, because that never happened on any of my wedding days.