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Bent derailleur hanger (claw adapter), maybe derailleur - AGAIN

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Bent derailleur hanger (claw adapter), maybe derailleur - AGAIN

Old 06-14-19, 03:17 PM
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Viich
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Bent derailleur hanger (claw adapter), maybe derailleur - AGAIN

Hi, just looking to bounce some ideas.

I have Shimano 1056 on my 88 Bianchi Strada, spread the rear from 126 to 130 to use modern wheels. Use an FSA 48-38 chainset, and 1056 8sp indexed rear dt shifters.

Yesterday on my way home, the chain dropped on a front shift, and all the sudden the rd was pulled almost into the wheel. I scootered the rest of the way home. I have been contemplating switching to an IGH on that bike anyway, but that's the second derailleur to get pulled around on that bike.

Any thoughts as to what might cause this?

Thanks.
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Old 06-14-19, 08:17 PM
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Chain suck up the rings' underside? Chain had a "wave" in it from the front drop off that traveled to the rear's cage and unshipped over the inner cage plate and caught on the spokes?

How worn are the rings and chain? Andy
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Old 06-15-19, 06:06 AM
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Originally Posted by Andrew R Stewart View Post
Chain suck up the rings' underside? Chain had a "wave" in it from the front drop off that traveled to the rear's cage and unshipped over the inner cage plate and caught on the spokes?

How worn are the rings and chain? Andy
Chain is probably ready for replacement, I'll measure. Rings should be OK, but I'll take a look a fire up a picture.
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Old 06-15-19, 10:05 AM
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Please measure the chain with a ruler, not one of those useless (IMO) chain checkers, so that you are not misled.
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Old 06-15-19, 12:03 PM
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Originally Posted by dsbrantjr View Post
Please measure the chain with a ruler, not one of those useless (IMO) chain checkers, so that you are not misled.
Always do. Chain was well into needing replacement - at 11 1/8


Chain Measurement


Derailleur


Derailleur

I think the derailleur should be fine - My outer ring though, looks to be done. Note to self to check chain more often.
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Old 06-15-19, 04:16 PM
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a new hanger must be aligned..

if 0 on ruler is on a pin center on the far end the chain is done

new chain pin centers are 1/2" and in 12" it would fall on the 12" line,,

'stretch' is sum of wear totaled over that length..

And clean that grimy derailleur...






....
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Old 06-15-19, 04:59 PM
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Old 06-16-19, 05:13 PM
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Originally Posted by fietsbob View Post
a new hanger must be aligned..

if 0 on ruler is on a pin center on the far end the chain is done

new chain pin centers are 1/2" and in 12" it would fall on the 12" line,,

'stretch' is sum of wear totaled over that length..

And clean that grimy derailleur...






....
That bike is now home to a sturmey 3sp, which I was thinking about doing before this broke. The freehub wheels never fit properly anyway.
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