Hi phantom, if you want a nimble and good handling bike, leave the standard suspension on an mc21 and get it sorted by a suspension specialist and it will feel much better and handle better than any modified mc21 with u/side down forks and single sided swing arms, how do I know?, iv'e rode both at trackdays for the last ten years and a well sorted standard mc21 is sublime. Good luck with your efforts.
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Proud Father of , 05 ktm 400exc supermoto 2018 honda crf rx supermoto