i had a bit of a revelation as i was putting a new cog on my big ugly pink bike; i realized that you can install and remove cogs without the aid of a chainwhip. i tried the
rotafix method and it worked brilliantly. just make sure to put a rag between your frame and the chain to avoid the scratchies. i love when i can find low tech fixes that might come in handy during road-side emergencies. never mind trying to find a 1/8" chainwhip...
anyone else ever tr this?