Er before you take to your bike with hammers, you could just take off the derailleur and pick the cog with the best chainline (which will probably be a decent gear for single-speeding with anyway. Cheapest (free) and quickest option.
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Er before you take to your bike with hammers, you could just take off the derailleur and pick the cog with the best chainline (which will probably be a decent gear for single-speeding with anyway. Cheapest (free) and quickest option.