



Added 11/6/2016 - Photo of OEM (non-ES) rear shock showing two spring design (this is Gen1 but all others are the same concept). On the SOFT setting both springs work together, on HARD setting the top spring is locked out.
http://www.fjr1300.info/photos/html/H0023.html
Revised 12/1/2017 - Cleaned up notes, revisions and added info for SOFT and HARD settings of rear shock, essentially with a calculation to show actual spring rate when the two springs are in effect when set to SOFT. However, the Gen1/2 numbers for look very low and unreasonable, despite the formula. One does not know preload in that setting, and one would tend to think there would be at least some, or enough to boost the effective load carrying capacity. The HARD setting numbers are simply the one spring K1 in effect as the K2 is locked out.
I have now installed my RaceTech shock on my Gen3 with an 850 lb. spring, with a touch of preload, but it is right on the money for a 190-220 lb. rider, validating that the RaceTech rear shock spring recommendations are high/too stiff, thus use Penske's recommendations.