I'm one of the rare folks who isn't displeased with the stock rear shocks. But with the mileage on my 2011 RGU at 42k I'm wondering at what point do you replace the shocks? I know you change fork oil and seals at 50k, but I haven't been able to find anything anywhere in print suggesting when to replace the shocks. What say you? When would you replace your rear shocks if you were happy with ride quality but want to be safe?