1) I seem to recall the MC21 wheel is a direct replacement. You will lose 1/2" of ride height though, and the MC18 is a bit low to start with, so the F3 link plates are a very good idea. Not only do they raise the suspension, but they also increase the suspension's "rising rate".
2) Forks are a direct replacement. All MC18, 21, and 28 forks are 41mm. Just slide the forks in. Use the corresponding axle and spacers. If using MC28 forks, use the MC28 calipers too. Don't understand why you want to change them though, unless it's for SE/SP stuff of course!
3) Front wheels are effictively all the same from R2J onwards.
4) Yes!
5) MC21 reed assemblies will go, but you will either need to very carefully trim the MC18 manifold or fit an MC21 inlet manifold. You'll understand why as soon as you take it off!
6) Pretty much! It's pretty self apparent when you have all the bits ready to go!
_________________
Andy.
NSR-WORLD.COM
Please keep all responses to Forum posts on the Forum so that others may benefit.
Please DO NOT PM me for technical advice. My time is precious, and you will probably receive a faster response on the Forum anyway.
Check us out on Facebook! Please "like" our page!