FRONT SUSPENSION CONVERSION:
RS250 forks: 7 lb. 10.5 oz. each
RS250 upper triple: 14.3 oz.
RS250 lower triple: 3 lb. 1.0 oz.
RS250 axle: 10.9 oz.
RS spacers; 3.1 oz.
NSR taper bearings: 3.9 oz. each
Brembo brakes 1 lb. 6.4 oz. each
RS250 rotors 2 lb.12.0 oz. each
RS250 clip ons 9.1 oz. each
NSR STOCK FRONT END:
SE/SP forks: 7 lb. 11.5 oz. each
NSR upper triple: 1 lb. 3.7 oz.
NSR lower triple: 3 lb. 3.0 oz.
NSR stock bearings: 5.4 oz.
NSR axle: 10.2 oz.
NSR spacers: 3.0 oz.
NSR calipers 2 lb. 4.0 oz. each (no pads)
NSR rotors 2 lb. 5.5 oz. each
NSR clip ons ~15.5 oz. each
The upshot is the rs forks themselves weigh almost exactly the same as the MC21 SE forks, but the whole rs front weighs approx. 2.5 pounds less - the main weight savings is in the Brembo calipers and the rs clip ons.
My 21 forks were basically stock so I can't comment on how re-worked MC21 forks would compare....but compared to stock 21 forks the rs USD jobbies have noticeably better compliance and feel. (For the money and for straight function, i.e, discounting pose value, I can believe the reworked forks is more cost-effective.) But the bigger difference with the rs front is in the braking - mondo stopping power and feel! (I run this with the Brembo radial master cylinder - had it with the stock brakes too, so that is not the difference - something in the combination of calipers or larger rotors, plus stiffer front end). Scott V. rode my bike the other day and nearly de-nutted himself first time he used the brakes. They are a one-finger deal now, but very controllable once you get calibrated to the power. Am I a good enough rider to need any of this? Not a chance! Do I like it? Yeah baby!
More than anyone cared to know, but FWIW. _________________
-Jim
'93 MC21