[Ryu James]

cdis,
i was going to suggest that you get a larger spur instead of just trying to make it work with a larger pinion. just take what your ideal gearing is and divide the 2 numbers to get the gear ratio. for example 15/48 is ratio of 3.2 so if you need to go to 50t spur then figure what pinion will get you close to the same ratio and your setup will be very close to what you wanted in the first place. eg. a 16/50 ratio is 3.12. just go up in spur size and this will require a larger pinion also and the result will be a mesh that works with your current spacer. if you already have a 54t spur on then i dont know what to tell you. i havent seen mod1 gears much larger than that.....although i am sure you could find one somewhere.