Chain skips

[Jim916]

I need to get my old mountain bike working properly since someone decided that my mountain bike and my wife's road bike would look better in their garage. I left the garage door open friday night and we woke up with 2 bikes missing. The road bike they walked to the back of the garage and removed it from the wall.

Anyways back to my question: When I sit and peddle it works fine, but when I stand up and peddle harder the chain will skip once in a while. I have almost hurt myself severely when the happens.

What will cause this? It has done this since it was brand new.

[Pickelfarmer]

I'd say either rear tire alignment to your front sprokets or your gear shifter is not lined up with your sprokets. Good luck.

[Ralph Wiggum]

Have you ever replaced the chain? I had a bike that I replaced the chain on, then it started exhibiting the same symptom. I took it in and they measured the gears versus the chain. Turns out over time, the chain and gears wear down a bit. With the new chain, the worn tooth spacing didn't quite match the new chain. A new set of gears solved the problem.

[Nate McVey]

I'm with Ralph, sounds like the teeth on your front sprocket are worn down and the links are skipping when you pedal hard. Best thing to do is take it in and have a bike tech look at it, otherwise buy a new front sprocket and change it out yourself.

[Pickelfarmer]

Yeah that's a good point. If this is an older bike then that could very well be the case. good call.

[yakfisher]

It is possible that it is a combination of all of these. If it is an older bike you probably do need a new chain you could have also broken a tooth on the rear cassette. I did this once and experienced skipping when applying heavy pressure to the cranks. It could also be that you just need a tune up. I would recommend taking to a bike shop and have them take a look at it, unless you are confident in your skills as a bike mechanic.