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My chain fell out while switching the gears and now it is stuck between the chainring and the frame. (I'm not a native speaker nor a bicycle expert, the terms may be wrong)

I tried to unscrew the bolts on the crank arm to remove the crank arm and the chain ring, but it didn't move after removing the bolt. How do I remove it or is there even a better option to get the chain out there?

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Update: I managed to wiggle the chain free with some force and it looked like the limit of the derailleur was not set correctly. In the picture you see like it looked before adjusting. enter image description here

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  • Usually I just gently pry it out in this situation.
    – Daniel R Hicks
    May 20, 2020 at 20:34
  • I did that just last week when I shifted the front derailleur too far inside at the same time as I shifted the rear derailleur by two cogs. I fixed the problem by finding a stick and putting it onto the chain, and then stepping on the stick.
    – rclocher3
    May 20, 2020 at 20:44
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    With a crank puller this is a 2 minute job (and another 5 to put the chain rings back on). Crank pullers are a few dollars, but $15 will get you a quality tool. Get you local bike shop to do it with theirs if you don;t want to buy one.
    – mattnz
    May 21, 2020 at 4:29
  • This where 2-piece cranksets are good. In an emergency 100 km from home you can still take them out and back with an Allen key. And a chain catcher would prevent the accident. Just thoughts for your next upgrades. The chain catcher is much cheaper than a crankset although easier to install on braze-on FDs.
    – Vladimir F Героям слава
    May 21, 2020 at 8:09
  • @Vladimir F That is really only applicable to pinch bolt systems like HT2, and even then you may run into trouble removing the preload cap without tools. Good luck removing DUB or any other self-extracting type system with your typical multitool.
    – MaplePanda
    Mar 30, 2021 at 5:43

3 Answers 3

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I've managed that before more often than I'd like to admit.

Normally you can wiggle the chain free, though it does take some force and may damage paint. Pull some slack in the chain by moving the derailleur forwards, or it will pull back on the chain you are trying to free up.

You've tried removing the middle and outer chainrings, but I think not the little chainring which is the one pinching the chain against the frame. This has four bolts of its own holding it on, accessible on the inboard side of the small ring. You can remove these one at a time while the crank is still fitted. It should give enough play to release the chain. I would try this first but if you can't rotate the crank to access enough of the bolts then it might not work.

So that gives option 2, removing the crank. To remove the whole crank needs a tool called a cotterless crank puller, cranks won't come off on their own just by taking the bolt out. Very searchable online for instructions. With the right tool available you'd probably just do this first anyway.

Remember to do all the bolts up tightly again. It's a good opportunity to clean them and add a little grease to all the threads.

If the chain likes to fall off the inner chain ring it needs looking at. maybe a tooth is bent, or the chainring is worn, or the limit screw on the derailleur is not set properly.

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  • Thank you for your answer. I'll try to remove the inner chainring tomorrow, but I'm not sure if that is currently possible, because i can't even turn the crank fully around. The chain stucks at bolts of the inner chainring while turning. Maybe remove some of those bolts is enough
    – andii1997
    May 20, 2020 at 20:43
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    You may remove the right crank entirely but you need a special tool for that, a crank puller. But no matter which way you free the chain re-adjust the limit screws of the front derailleur to avoid similar accidents in the future. On youtube you'll find videos how to do it.
    – Carel
    May 20, 2020 at 20:52
  • If you can’t undo the bolts on the little chainring, breaking the chain is much easier than removing the crank. If your chain has a quick link, it’s very easy. If not, you need a chain tool, which is less expensive and more useful to own than a crank puller.
    – Andrew
    May 20, 2020 at 21:14
  • @andii1997 good point, it's worth a try but otherwise onto pulling the crank.
    – Swifty
    May 21, 2020 at 7:22
  • @Andrew I fear the stuck piece would still stay where it is.
    – Vladimir F Героям слава
    May 21, 2020 at 8:11
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Happened to me a couple times. It depends on your frame and the gap between the bottom bracket and the chainring, but usually it can be fixed without removing the whole crank arm and chainring.

What I usually do is pull the chain downwards from below and the rear part of the frame and gradually try to make my way forwards until the chain gets freed. It sometimes require to play a bit with the cranks, slightly turning them to use the leverage they provide to move the chain.

Because the chain often gets obstructed by chainring bolts and some lateral pressure applies (chain gets bent sideways), the process is tedious and difficult.

The bottom line is that you will need latex gloves or a good wash and that you should certainly be prepared to do it again if your front derailleur is not adjusted well.

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I kept having this problem after I changed to a new crank set. The new crank had a larger gap between the smallest chainring and the bottom bracket. I fixed the problem using a plastic wheelbarrow bushing that I cut to fit between the crank and the frame. It works great to keep the chain out of that little space.

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    You should edit your answer to share a picture!
    – rclocher3
    Mar 30, 2021 at 2:09

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