single speed mtb chain slipping

crazyfell38

hey i am new here and i was just wondering if anyone can help me out with the problem of my chain keeps slipping when i pedal a little bit hard. I took my bike to lbs and they said that my chain was fine and the sprockets were near new if any one can help me out that would be much appreciated. http://i.stack.imgur.com/F4Gt2.jpg http://i.stack.imgur.com/ynded.jpg

StinkinHippy

Are you sure it's the chain slipping on the cog and not the cog slipping on the freehub?

This is assuming of course that you've checked chain tension and set the wheels right in the dropouts?

crazyfell38

its defiantly the chain beacuse half of the time the chain pops off the rear sprocket and yes the chain line is straight and the gt ruckus which is my bike doesn't have drop outs

The Rookie

Chain looks stretched, you can see the teeth at the top of the chainring pulling on it and at the bottom there is a visible gap, whether that is definately or defiantly I'm not sure.

Of course your bike has dropouts, it's where the wheel goes, it doesn't have horizontal or sliding ones at the rear but vertical ones.

cycleclinic

For a single speed sprocket with tall teeth it would take monumental wear for it to slip. Lack of chain tension is the likely culprit. Had a customers bike do this on the ratio he gave me so I swapped the 16T sprocket for a 17T. This increase chain wrap needed by 1/4" in other words it pulled the tensioner more and the chain tension increased and it no longer slipped under power.

redvee

Run the chain over the chain tensioner instead of under it so that the chain wraps around the sprocket more.