I have .90 RaceTech springs and the stock spacers needed to be cut about an inch IIRC. Easy way to do it: have front end lifted off of ground with forks fully extended. Place spacers and caps with preload adjusters fully wound out and see how far you must compress the stack to get them to thread in. Stock spacers were WAY out needing a really hard effort to compress and get threads started...which is no good. Cut spacer until maybe 1/4" needs to be compressed to get the threads started and this will be about right. If you can't get your sag set properly...either cut more of the spacer or add washers to suit. Not hard and no real measuring needed....if you can compress the spring a bit to get the cap on it's going to be really close.