Hi! The chain on my mother's mountain bike fell off the large gear and slipped inbetween the frame and the gears. Actually, it's stuck, and I can't get it out! What i need to do is remove the gears so I can free the chain.

Already I have used those 6-sided screw tool to remove a bolt. But still the crank arm and gears do not come off? What do I need to do to remove the gears? Note-the bike does not pedal because the chain is stuck.

Attached are photos of the stuck chain, the gears, and the bolt. Please help me save this bike!

P.S. Don't bother to tell me to take it to a shop. I'm into learning and collecting tools.

Do you have access to an oxy-acetylene torch, or some plastic explosive?

You need a crank arm remover. There are 2 different types of removers. If you have a square spindle you will need Park Tool CCP-22 and if you have a splined spindle you will need Park Tool CCP-44.

the park tools website ( https://www.parktool.com ) will provide you with
lots of the info your looking for and will need.

good job on looking to learn it yourself!

also... making your post subject-line relevant to your post will help others with similar issues
find this and learn for themselves.

If the chain slides, you can disconnect the chain with a chain tool (or use the quick-link if there's one) and slide it through.

^ I agree if you break the chain then you can give the chain a slight twist or rotate crank and I think it will come out, or just remove crank arms

I reckon I could get that chain out without tools.

Chains are tricky buggers; there's a real technique to dealing with them when they get tangled. I wouldn't be surprised if that chain eventually comes out easier than you think...

I'd take a jockey wheel out of the rear derailleur or split the chain if it has a quick link first, just to make life easier. I'd put a glove on my right hand and pull on the lower length of chain (with the bike upside down, paying careful attention to the direction I'm pulling), while using my left hand to pull on the other end to get it out of that trap while a helper slowly turns the crank.

By the way, I'm enjoying the irony of those tangs causing the problem they're meant to prevent... maybe you could just bend them out of the way with some longnosed vicegrips.

Why as I matter of facxt I do have access to the former. Were you going somewhere with this?

Thanks, I saw that website before while searching how to remove a crank arm. Haha, I accidently wrote "!" as my subject header and couldn't change it! I'm amazed I already got 6 posts though!

Probably Mythbusters...

I don't often do this but I'm going to say "Bike Shop".

They'll be able to get the chain out and readjust the front derailleur so that it doesn't happen again in probably less time than you've spent reading this thread.

I agree that a good bike shop might be the easiest way to get this done... but it will be cheaper to buy the $10 crank puller tool and carefully adjust the shifting yourself to make sure it doesn't happen again.

I would have to agree with the bike shop recommendation at least this time.

If you don't even know what to call a socket wrench you need to take the bike to a shop so they can do a proper adjustment and check the chain for damage. And it's not necessarily cheaper to do it yourself if you do it wrong. In my opinion it would be best to have them give the bike a "tune-up" - basic lubrication and adjustment of gears, brakes, etc. That way your mom will have a safe, properly operating bike and you will have a good base from which to start and some time to learn

If you insist on skipping the shop then start learning by reading about bicycle parts and repair and watching videos online and limit posting individual problems until you understand more of the procedures and terminology. It can be difficult to learn 2nd hand, though, so check to see if a shop, bike co-op or knowledgeable friend can show you the basics. If you do post here, first read check the resources at the head of this forum (READ THIS, Sheldon links).

Remember - no matter what you study something will be left out that you will face eventually. Bike repair, like anything that involves a system of interrelated parts, is not memorizing what to do, but understanding how things relate to and affect each other, so that when you meet new situations you can analyze and solve them. Because a bicycle involves parts performing different functions connected both to a central core and to each other, at angles that affect their interaction, are exposed to the elements and impact, and also interact with the human body, bicycle maintenance can be both one of the most challenging and rewarding activities you can do.

P.S. DO NOT attempt to remove the crank with anything but a crank extractor and make sure you use it properly or you will have an expensive problem.

Wow, all these replies but no one mentiones the funky Thread title... If other people have a similar problem they could find it if the thread has a decent title.

PS: Sorry, to not answer your question, but the '!' tricked me into reading, hehe!

Post #9.

I will reiterate my feeling that this job does not require a shop, even for someone new, and especially for someone with the will to learn bike mechanics.

Whoops, didn't read that post that well... Sorry!

i would just spend $5 and get a link remover and take the chain off if i could not pull it out with a set of pliers.

This might be a simple way to do it, but could wind up weakening the chain so would not be my first choice.

Yes, even on chains of an older design, I'm still loathe to reconnect a link. OP- get a reusable quick-link.