*Keep in mind, these are only recommended rates to get you close for weight that will work pretty well for most riders. Optimum spring rate is affected by countless variables including riding style, preference, pace, track layout and surface finish, and bike geometry and suspension setup.

Yamaha R3 (all years)
Rider Weight (not including riding gear)Fork Spring RateShock Spring Rate
<120.66 kg (stock springs)900 lb (155N)
110-140.70 kg (7.0N)900 lb (155N)
120-150.725 kg (7.25N)1000 lb (170N)
130-160.75 kg (7.5N)1000 lb (170N)
140-170.775 kg (7.75N)1050-1100 lb (185N)
155-185.80 kg (8.0N)1050-1100 lb (185N)
175-205.825 kg (8.25N)1150 lb (200N)
190-220.85 kg (8.5N)1150 lb (200N)
210-240.875 kg (8.75N)1200 lb (215N)
225-255.90 kg (9.0N)1200 lb (215N)
235-275.925 kg (9.25N)1200 lb (215N)
250-280.95 kg (9.5N)1200 lb (215N)
270-300.975 kg (9.75N)1250 lb
>2901.0 kg (10.0N)1250 lb
Kawasaki Ninja 400 (all years)
Rider Weight (not including riding gear)Fork Spring RateShock Spring Rate
<120.66 kg400 (70N)
110-140.70 kg (7.0N)425 (75N)
120-150.725 kg (7.25N)450 (80N)
130-160.75 kg (7.5N)475 (85N)
140-170.775 kg (7.75N)500 (90N)
155-185.80 kg (8.0N)525 (90N)
175-205.825 kg (8.25N)550 (95N)
190-220.85 kg (8.5N)575 (100N)
210-240.875 kg (8.75N)600 (105N)
225-255.90 kg (9.0N)625 (110N)
235-275.925 kg (9.25N)650 (115N)
250-280.95 kg (9.5N)700 (120N)
270-300.975 kg (9.75N)750 (130N)
>2901.0 kg (10.0N)750 (130N)