bike chain keeps popping off from the sprockets?

I'm a little confused. They sold you two chains for one bike at the same time? Why?

Is the chain coming off the front chain rings? If so your chain may be fine and you simply need derailleur adjustments. A chain problem is rarely the cause of dropping a chain off the chain rings. A bent thooth could be the problem as well. Didn't a shop employee test ride your bike? That should have shown them what the real issue is. I suggest you try a bike shop other than the 2 you have dealt with. It's the shop's responsibility to listen to the customer and test the repair to verify the problem is fixed.

I'm not quite sure what your saying but I gave it a shot.

It's definitely the derailleur. The derailerur and/or the cable needs to be adjusted. What's probably happening is that when you shift gears, the deraileur is not aligning the chain on the sprockets right, so it's "between gears" and the chain jumps off the sprockets.

It's kind of like the clutch not engaging fully on a car, and not being able to shift into certain gears.

I had this problem with a lot of my bikes.

You need to get the deraileur adjusted, probably by tigtening or loosening the shift cables so that it will align the chain right when you shift gears.

I don't know why those other answers were voted thumbs down...they were good answers. Sometimes I think people just come and randomly click thumbs down on answers because they think it's funny.

There are a lot of contributing factors to your problem, and they all need to be looked at by a competent bicycle mechanic.

1. The condition and the length of your chain.

2. Do you have the right chain for your bike? They come in different widths depending on how many gears you have.

3. The condition of your chain rings and the cogs on your rear wheel.

4. Are your derailleurs working correctly, and are they in adjustment?

5. Are your shifters working correctly, and are they matched to the gears on your bike?

6. Are your cranks loose?

7. Is your rear wheel mounted straight in the bicycle's frame?

8. Is the frame bent?

9. Are you shifting correctly? What are you doing when the chain comes off?

Find another bike shop if you can. I don't know why no one has gotten to the bottom of your problem yet, but it's really not that complicated. Mechanics in general, tend to be cold and impersonal, and they have a way of intimidating people who know very little about mechanical things. Don't be intimidated. It's ok to not know as much as they do. Mechanics also tend to only hear and understand the technical language regarding the products they're working on. Be persistent until you're satisfied they understand what you are saying. Have them ride the bike so they can see the problem for themselves. Have them watch you ride the bike so they can see if there's something you're doing wrong.

Good luck.

I would find another shop or have a friend that knows something about a bike take look at it. First off they should not have sold you two chains in the first place. Second the first shop should have cut the chain to the correct length. What do you mean by ticketing the chain ? If you replaced the chain did you cut it to the correct length.

Anyway, I would go to another shop and explain to them what happened.

As you know when you shift gears there is a devise that moves the chain to the next gear. When you shift, shift one gear at a time. If it continues to do this, you might have better luck going to a completely different bike shop and ask them to give you a complete tune-up and start over with a new chain. Be sure to keep your chain clean and oiled.

I generally re attach the chain myself. But when it happens every time, a tune-up may be in order. Get another guy to do it though.

losen up your back tire and pull on it and then tighten it up every time it get lose but only losen it up to where it moves back but wont pell back forward

you need to adjust rear and front derailleur.