Originally Posted by
FastJake
1
3. There are two ways to get a straight chainline: move the chainring, or move the hub on its axle. Moving the chainring is easy (just add more or less washers after completing #2 ^^). If you move the hub by rearranging spacers you will probably find that your rim is not centered in the frame anymore. You will then need to have your wheel re-dished. My LBS charged me $10 to do this.
As long as you replace the amount of room taken up by the cogs(and their spacers) there will never an issue of centering your wheel, its just not possible if you have the right spacer arrangement. Its a pain to do, but can be done.
To remove certain cogs from your freewheel, first step remount it back on the wheel. Then get two chainwhips(both 3/32" pitch, not track chainwhips) Put one on one of the larger cogs and hold tight. Put the other one on the smallest cog and twist counter clockwise. It will unthread. You might have to unthread the second smallest cog too. Now take a Digital Caliper and measure hyper acuratly the size of all the spacers and cogs that exist on the freewheel. That is the same amount your stack of spacers and one cog that you are going to use. It will take some reassembling and playing around to find the right chainline, but it always needs to be that thickness.