we'll this is my atempt to help i'm only doing this 1 time lol
first off pics dude pics would help as the rest of what im goint to say is a guess dont know the bike but i think it has a twin spar frame right?
if so forget the reservoir typ shock as they wont fit
i have a agb 29 so im only going on that but i think the bikes the same just smaller ?
just sit bike on bucket or something milk creat< undo shocl top and bottom
measure shock fron bolt hole to bolt hole
dunno there size as mines bigger id say
probly like 270mm as a guess or 280mm
what ever get size go on fleebay and buy a new 1 sheesh
trying to fix a pretty crappy shock at the best of times ,is a waste of time
buy a new 1 bolt it on and go for a ride , come backhere say cheers lads for all ya help,THEN deleat this thread