Rodabod answered your question very accurately, but you asked the wrong one. You don't need a 16-tooth freewheel, just as 16-tooth cog. You may find that if you take your existing cassette apart (carefully), you'll have a good set of usable spacers (though not enough to cover the gaps left by taking out the 6 other cogs).
Rodabod answered your question very accurately, but you asked the wrong one. You don't need a 16-tooth freewheel, just as 16-tooth cog. You may find that if you take your existing cassette apart (carefully), you'll have a good set of usable spacers (though not enough to cover the gaps left by taking out the 6 other cogs).