Hi this is Jeff with The Two Wheeler Dealer.
Today I’m going to demonstrate how to fix a bike chain that has fallen off. And on this
particular bike the chain has fallen off on the rear cog as well as the front chain ring.
First place to start would be to just loop it back over that rear cog like so. And then
you’re going to start on the top of the front chair ring and just place the chain back on
the teeth while slowly peddling forward and it should seat itself back on. Now at this
point check the chain tension. Make sure it’s not too loose. This may have been the cause
of it falling off in the first place. If it is all loose and floppy you then need to re-tension
the chain by loosening the rear wheel and sliding it back in the drop outs to give that
chain a little more tension. Do this with two 15 millimeter wrenches. Do this on both
sides. At this point the wheel should be free to pull back in the drop outs. Pull it back
until the chain has good tension on it while centering the wheel between the drop outs
of the frame making sure it’s straight. And then snug those bolts back down making sure
that the wheel hasn’t slid while you tighten it and it still maintains the proper chain
tension. And that’s how you fix a chain that has fallen off.