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-   -   Crossed Chain (https://www.bikeforums.net/showthread.php?t=1188137)

fullergarrett 11-16-19 06:56 PM

Crossed Chain
 
I was placing the rear wheel back on my bike when I noticed that my chain was crossed, and in a couple spots it “looped.” Any ideas on an easy way to fix this? This isn’t the first time I’ve had this happen to a bike - my other bike is out of commission for a similar problem. Any help would be greatly appreciated.

https://cimg7.ibsrv.net/gimg/bikefor...899fb6ad7.jpeg
https://cimg8.ibsrv.net/gimg/bikefor...43a8750e1.jpeg

bobwysiwyg 11-16-19 07:36 PM

This might help..


DOS 11-16-19 07:36 PM

Take a pic of the rear derailleur.From I can see it looks its pivoted back and down so what should be the upper pulley is down. You have to pivot the body forward and up, catching the chain from the underside with the casette while pulling the wheel back toward the drop out.

DOS 11-16-19 07:40 PM


Originally Posted by bobwysiwyg (Post 21212126)

Forget what I said, do this.

zacster 11-17-19 09:04 PM

Stand it up. Get it onto the chainring in front, then take another picture and get the entire frame in. It is hard to tell what the derailleur and front look like. You can't tangle a chain if it hasn't been taken off.

fullergarrett 11-22-19 06:48 PM

Unfortunately, I still haven't been able to fix it.

I stood up the bike and followed the steps in the video. Seems like it is going to work, but I can't get enough slack on the chain to remove it off the sprockets - even when moving the rear derailleur. There appears to be a guard on the rear and front derailleurs as well.

https://cimg3.ibsrv.net/gimg/bikefor...0ab1046367.jpg
https://cimg2.ibsrv.net/gimg/bikefor...2e437df338.jpg

Rear derailleur
https://cimg4.ibsrv.net/gimg/bikefor...374608b61a.jpg

Front derailleur

zacster 11-22-19 09:18 PM

You are still upside down in those photos. Stand it upright the way it should be when riding. Put the front wheel back on and prop up the rear. Gravity is making your chain go the wrong way and gravity will fix it. That chain is rusted too, maybe just get a new one.

Miele Man 11-22-19 09:50 PM

I'd just use a chain tool to take a pin most of the way out of a link and then simply unwrap the chain and when that's done put it on a long board or surface that I know is straight and see if the chain got twisted. If the chain is twisted I'd get a new one. If the chain isn't twisted I'd put it back on but use a quick-link of some type to join it. That'd entail taking out 1/2 of a link. If it's an 8 speed chain or less then you can probably put it back together with the chain tool. I think in your case though a quick-link would be a better join.

Cheers

cobba 11-23-19 01:14 AM

As said before, take a pic of the rear derailleur that shows it attached to the frame.

A side on photo like the following would be good.

https://cimg9.ibsrv.net/gimg/bikefor...27e7a4e25f.jpg

shelbyfv 11-23-19 06:41 AM

Learn to lube the chain:thumb:

fullergarrett 11-23-19 01:08 PM

I’m about to run to my local Walmart to pick up a chain repair kit that hopefully has a chain tool in it. I’ll also pick up a new chain just in case. Unfortunately, for me, the nearest bike shop is 20-30 miles away.

I hope these pictures are more helpful.

https://cimg7.ibsrv.net/gimg/bikefor...b4806afa9.jpeg
https://cimg6.ibsrv.net/gimg/bikefor...97b76a13b.jpeg
https://cimg5.ibsrv.net/gimg/bikefor...a7e6ab2da.jpeg

DOS 11-23-19 02:21 PM

Isn’t it just a matter of opening the front loop in the chain and looping in over the crankset as demonstrated in the video?

Also, don’t buy bike stuff at Walmart.

fullergarrett 11-23-19 02:33 PM


Originally Posted by DOS (Post 21220642)
Isn’t it just a matter of opening the front loop in the chain and looping in over the crankset as demonstrated in the video?

Also, don’t buy bike stuff at Walmart.

I tried that and had no luck. Maybe I can open the chain, get it off and go from there.

I went to Walmart. Trust me - I try to avoid buying stuff (especially bike-related items) at Walmart. But the nearest bike shop is ~20 miles away and I don't have room in my car to lug my bike there. I ended up buying a new chain and a bike repair kit at Walmart. They didn't have the chain tool so I had to buy a $20 bike repair tool kit that has the one tool I need.

It still baffles me how the only bike shop here (a college town, mind you) closed a couple years ago. But then again most people usually throw their bikes away and get a new one when something as simple as a flat tire happens.

fullergarrett 11-23-19 06:38 PM

I called up a friend and he knew someone who works on bikes. We were able to get the chain problem fixed. He said it happens pretty often with him too, but it took a while for us to figure it out since it was pretty bad. He actually had to undo the original chain and put it back together. But it works fine now.

Thanks everyone for your help.

fullergarrett 12-02-19 02:20 PM

Unfortunately, it's back to being twisted up. I had to remove the rear wheel and went to put it back on and the chain managed to become all twisted up again. This time the bike was sat right-side up, it wasn't laid down on its side or (worse) upside down.

I know when my friend's friend worked on the bike, the only way we could get the chain untwisted was to actually break it off, take it off and straighten it out, put it back on and link it back together.

But it seems like it doesn't matter how careful I am - when I remove the rear wheel, the chain always manages to twist itself up like a pretzel. Could there be an explanation for why it keeps doing this. Anything to prevent it from happening in the future?

RubeRad 12-02-19 03:36 PM

I've had that happen as well. It's like a 'blacksmith puzzle' -- the chain got that way without being taken apart, so there is guaranteed a way to get it back without taking it apart.

When I take a rear wheel off, I first shift to the smallest cog because then I know which cog to put it back on, and that's the easiest cog to do it with. Undo the QR, grab the RD by the pulley and pull it way back as far as possible, then take the wheel out. Holding the RD and having the chain somewhat stretched out, it is under control at this point. Let the RD go back to its neutral position, and watch the chain as you do it that it doesn't get kinked. It might help keep it untangled if you put the chain on the big ring in the front. It might also help if you have like a chair or something nearby with a stick or a screwdriver sticking off the edge, holding the top (upsidedown bottom) half of the chain up in the air until you're ready to put the wheel back in.

Also that's a great video up there in post 2, should make everything clear. When you have the bike upside down, don't let the chain fall off the crankset and over the pedal, and don't let top (upsidedown bottom) of the chain fall down past the derailleur

fullergarrett 12-02-19 04:29 PM


Originally Posted by RubeRad (Post 21230688)
I've had that happen as well. It's like a 'blacksmith puzzle' -- the chain got that way without being taken apart, so there is guaranteed a way to get it back without taking it apart.

When I take a rear wheel off, I first shift to the smallest cog because then I know which cog to put it back on, and that's the easiest cog to do it with. Undo the QR, grab the RD by the pulley and pull it way back as far as possible, then take the wheel out. Holding the RD and having the chain somewhat stretched out, it is under control at this point. Let the RD go back to its neutral position, and watch the chain as you do it that it doesn't get kinked. It might help keep it untangled if you put the chain on the big ring in the front. It might also help if you have like a chair or something nearby with a stick or a screwdriver sticking off the edge, holding the top (upsidedown bottom) half of the chain up in the air until you're ready to put the wheel back in.

Also that's a great video up there in post 2, should make everything clear. When you have the bike upside down, don't let the chain fall off the crankset and over the pedal, and don't let top (upsidedown bottom) of the chain fall down past the derailleur

When taking the rear wheel off the bike, I typically shift it into the highest gear (smallest cog) on the rear derailleur before removing. I didn't have this issue until lately, when it seems like it does it every time I remove that rear wheel.

I tried doing what was shown in the video, and had no luck. Last time we ended up having to remove one of the links and remove the chain, straighten it out and put it back together. This chain doesn't have a master link, so I'm afraid to remove one of the links in case it doesn't want to go back together. But on the other hand, it's already broken - I don't think I can make things worse. :lol:

RubeRad 12-02-19 04:37 PM

If you maintain tension on the chain when you remove the wheel, and focus on placing the chain in a stable position before turning your attention to the wheel, hopefully it can stay in place.

Also, you might want to consider propping the bike upright so the chain can't sag and loop (make sure the top part of the chain can't fall off the crankset and fall below the lower part). Of course a bike stand lets you keep the bike upright the whole time (although I always feel like I need the bike on the ground and gravity assistance when aligning the wheel and tightening the QR)

tomtomtom123 12-02-19 05:20 PM

You don't need to break the chain. It cannot "knot" itself when it's a closed loop and passing through the rear derailleur, so you simply have to unfurl the loops. The video posted earlier is the best explanation of why it happens and how to undo it, and if you watch it a few more times, it should be easy to follow. Just do what the video says, and 1) try moving the loops out as far apart as possible, 2) flip the chain around the pulley/jockey wheels of the rear derailleur since it's the easiest reference point that cannot be messed up because the chain cannot twist when it's passing through the derailleur, and then continue running the chain along the chainstay from the RD until you loop it around the chainring. When it gets over the chainring, the chain should have already unfurled itself.

Do exactly what the video does starting at 1 minute and 54 seconds. The video shows what happens when the bike is upside down, but if your bike is right side up, it's exactly the same process, except you're going to be flipping the chain over the top of the chainstay instead of under the chainstay.
youtu.be/6iuLauaK0Ao?t=114
Copy the text above and paste it into your browser so that it goes directly to 1:54, or 114 seconds into the video. He says "knot", but it's not technically a knot. It's just a loop.

tomtomtom123 12-02-19 05:52 PM

Here, I marked some of your photos. The problem is that you're wrapping the wrong side of the chain and wrong direction onto your cassette. The chain coming out of the upper pulley/jockey wheel (the wheel at the center point of the pivot) wraps around the cassette. The chain coming out of the lower pulley/jockey wheel (the wheel at the very end/tip of the cage that swings) runs along the underside of the chainstay towards the chainrings. And you should not be running/pulling the chain to fix the loop, but instead you should unfurl the loops while keeping the chain stationary.
https://cimg3.ibsrv.net/gimg/bikefor...df134ac884.jpg
https://cimg4.ibsrv.net/gimg/bikefor...5f9a42c60d.jpg
https://cimg7.ibsrv.net/gimg/bikefor...b6c30faa76.jpg
https://cimg9.ibsrv.net/gimg/bikefor...d0360bc358.jpg


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