This is the conclusion and resolution to the spring issue I was having. I am posting this for future reference for other users who may be wanting to do the same upgrade but would like to replace the spring:
My other thread which goes through some of the other details of this job is linked here: https://www.svrider.com/forum/showthr...82#post2655382
I think this post is important because it will allow SV650 owners who want to upgrade their suspension to be able to change out the ZX-14 & ZX-10 shock springs easily and cheaply to better match their weight and riding style, and not have to settle with the ZX factory spring rates.
To recap the other posts I Purchased a ZX-14 shock to upgrade the suspension on my 2003 SV650. I am about 180lb before gear so I wanted to replace the spring because the ZX-14 has a 543lb spring, and for my weight I needed about a 475-500lb spring. I purchased a Hyperco 500lb spring at Christmas with the inner diameter of 2.25'', and 7'' long to replace the factory ZX-14 spring. After I purchased that spring I found out that while one end of the shock takes a 2.25''id spring, the upper end is actually smaller. This creates a problem where the spring is not held in place in the center of the shock, and could cause binding. The original ZX-14 (and ZX-10) shock spring are actually 4mm smaller on the high end to compensate.
NEIMIS helped me with finding a solution to this problem. He found out that RACETECH.com makes a custom conversion collar for putting aftermarket springs on ZX-14/10 shocks. The part number for this collar is SPSC B5855. This collar will allow ANY 2.25''id spring to perfectly fit, and the best part is that it is only $2.99!!
They mailed me the collar and I got it today and they didn't even charge my for shipping!! I put it on my ZX-14 shock and it fits perfectly. To remove the original ZX-14 spring a motorcycle spring compressor is required. There are relatively cheap, or you can just take it to a dealership. Once that spring has been removed a spring compressor is not needed to put the new 7'' spring back on. There is enough threading on the spring tensioner nuts that they can supply plenty of preload and be let out enough to fully take the spring off and replace it with another 7'' spring if you are going to the track or something. Many of the racing spring options for shocks like these are 7'' for this reason.
I hope this information helps others. I would be happy to answer any questions. Happy riding.
Anyways; here are some pics with small descriptions:
Origional silver ZX-14 shock and spring alongside the new blue 500lb 2.25id 7'' spring.
RACETECH.com custom collar for fitting any 2.25id spring on a ZX-14/ZX-10 shock.
Custom collar fitting into the top of the new spring.
New spring on ZX-14 shock fitting perfectly. (there should be a little play, but not enough for it to slip off center)
Closeup of custom collar fitting over the original threaded collar.
Me working on the bike in my apartment. I hope the banging didn't bother my neighbors! lol