After my rear shock
https://zeromanual.com/index.php/Unofficial_Service_Manual#Rear_Shock failed on my 2013 S, and I couldn't find a reasonable replacement; I went to the internet!
It took me 4 shocks to find 2 that almost fit, and I'm still looking for a good 5th final one.
Substitutions
2013-2014S - The Yamaha R3 has the same length rear shock, but the spring is too wide; it doesn't fit.
2013-2014S - Fastace Rear Shock BDA-51AR/58-AR has a weaker spring, and is rotated 90 degrees; it doesn't fit.
2013-2014S - Wotefusi 260mm Central Air Shock Absorber Universal Fit - fits when mounted upside down. Need to cut/grind down the bushing.
2013-2014S - TDPRO 260mm 10.2 Almost fits; the area on top of the spring is just slightly too large. I had a welder make a mounting bracket, but now the rear of the motorcycle sits up higher. See the attached pictures.
Next thing to perfect the rear suspension -
Option A: put a lowering bracket on it to get it closer to stock.
Option B: Find a shock that's ~ 1 inch shorter (~9.2 inches) with similar spring characteristics. A lot of what I see in that range is either 1200lbs or 400lbs when a 500lb-960lb would probably be optimal.