My BMX bike chain keeps falling off when I pedal fast.?

When I go uphill I hear a cranking noise. Any suggestions on how I can fix this?

If the chain is properly tensioned (a little slack, but not loose), then it sounds to me like you may have a lot of flex in either the frame or the front sprocket. If it flexed enough under a heavy pedaling load, it's possible it could derail the chain (and chew up teeth in the process, or chew/twist the chain). Take off the sprocket and see if it lays flat. Eyeball the teeth to see if any are bent or missing. Check out the rear cog while you're at it. With the chain on the bike, put some tension on the cranks to pull the chain tight and sight down it from the rear to see if it's twisted.....keep rotating to a new section of chain until you're sure every link is in good shape. Also, if the chain is rusty you might have some stiff links that could cause it to skip and derail (proper tension will minimize that).

Another possibility is if your wheel is slipping under load, making the chain slack. If you don't already have tensioners for the axle, get some.

Get a pair of chain tensioners (those little things that bolt on the rear axel), and the noise might mean that your rear wheel is misaligned. I know it hurts to have a chain fall and hit platform pedals.
check your barrings and make sure your chain is tight if so your chain may need to be replaced they do stretch out after a lot of ridein
Then stop pedaling fast Diddy man!

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Street Bike Exercise Bike Stationary Bike Recumbent Bike Bmx Bike Kids Bike Schwinn Bike Cruiser Bike Road Bike Folding Bike

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