yes ive got a honda rs 125 shock for my 21sp,you will need years 1998 onwards.the shock dosnt need revalving but needs to be resprung because of the weight diference in the bikes,maxton did mine and set it up to my weight for £70.i got the shock from breadline racing who i used to get my rs parts from,cost £90 and is brand new 
the only thing is you will have to run a tyga subframe and seat or an rsw like mine hope thats useful mate 
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ive seen more tarts than mr kipling