Why does my bike chain keep skipping?

[Dexter49]

I have a Vertical BMX bike. My problem started small. Usually when I started from a stop or put a lot of pressure on the pedals going uphill, my chain skipped or something to that effect. Now it gets to the point where I barely ever get anywhere pedaling. What's happening? I've tried moving the back wheel further back, but that doesn't seem to do a whole lot. Any other suggestions as to what the problem might be and how I fix it?

 

[dabac]

Stretched chain and/or what's called sprocket and chainring in the regular bike world. In BMX-speak often called driver and sprocket. Do a search for "measure chain wear" and see what you come up with. Sheldonbrown.com has pics on how to identify worn sprockets and chainwheels. Once you've figured out what, it'll have to be replaced. These parts wear together to fit together. Start with a new chain. If you still get skipping, replace the thing at the rear. If you still get skipping , replace the front.

 

[alfeng]

OR, it is possible that the pawl(s) in the Freewheel is/(are) sticking ...

• Lubing is problematical ... a temporary "fix" is to try to seep some silicon spray lubricant into the mechanism to un-gum the grease ...

THAT would be a temporary fix ... BUT, it's easier to just plan on buying a replacement Freewheel which will typically be less than $20. FWIW. I recommend ACS CLAW Freewheels ... they are available for use with standard 1/8" chains or 3/32" "Road" chains. check www.Danscomp.com if your local LBS doesn't carry BMX "stuff" OR to use as a reference ...