Sorry…I should have actually done the math for the (probably majority) audience that is unfamiliar with the concept of heart rate reserve (HRR). I’m trying to walk the line between patronizing and informing. 
Let’s say peak cycling heart rate is 185. Let’s say resting heart rate is 48. HRR is 185-48 or 137. 95% of HRR is 137*0.95 = ~130. So if you want to be pretty sure your in that 90%+ VO2max training zone target a heart rate of 48+130 = 178.