Hello! i have klein attitude race 2002 year. I want change my xt 770 cranks, wich converted to 1x9, to more lighweight cranks. What can you reccomend me? I found xtr 970 wich lighter 80 gramms? and new 12 speed Sram dub standart cranks wich is more light than xtr 970, but can they run with 9 speed cassete? maybe change to 11 speed chain? and the difference with chainline, i have 50, sram dub have 49 is it ok?