What is the best size cog for a 42t chain wheel?

Question

i have a freewheel road bike and i have a 42t chain wheel and a 16t cog but when i ride i get a slip sometimes but i cant figure out why the cog appears to be wearing down but is it because i should have more or less teeth

Answer 1

if it worked well at one point and is now skipping it is either worn out or something isnt together right.  make sure your wheel is seated in the dropouts and running straight in the stays.  from there it may be time for a new chain and sprocket.  these are wear items and need replaced from time to time.  chains stretch and cogs wear from grit getting into the works.  

Answer 2

If you have a 42 and 16 then that is the best combination already.  Only thing i heard from a friend of a friend  to look out for is having the chain  too long,but i heard also it's easy to fix, just subtract 2 links from the chain and the slipping should vanish like magic.

Answer 3

If u r sliping then maybe u should ride a smaller chainwheel, maybe a 10 or a 12. This will give ur ride a much tighter feel...

Answer 4

Sounds like you need to replace the sprockets and chain.  The chain stretched and wore out the sprockets.