Derailleur in the cogs (not my bike)

[summerdays]

I walked to the shops yesterday and on my way home met two retired ladies looking at one of the bikes.... because it wouldn't move. I offered to help making an assumption the chain was off and that I could quickly send them on their way.

It wasn't, the chain was on the two big rings, and the derailleur was actually pulled into the rear cassette. It wasn't but budging an inch. I managed to ease it free eventually.

Trying to remember the details of the bike it had a Mixte type frame but the components looked modern but I didn't pay enough attention to it to say more than that.

Once I'd freed it the derailleur didn't seem to be vertically under the cogs so I suggested she head to the bike shop rather than out on a ride with her friend.

She said it had locked up before and her son described it as having a "hungry chain" which is a term I've never heard before.

Why have I started this thread? I'm just trying to work out the why it happened.... what is this hungry chain comment, I assume the chain was too short (even though you shouldn't be in big/big ring combo), as presumably it shouldn't be so short that it ends up in the cogs.

 

[summerdays]

[QUOTE 5046103, member: 9609"]I'm going to guess the freehub was sticking which meant when you try and freewheel the cassette keeps pulling on the chain and it pulls the hanger up and forward. You can get home when this happens if you never stop pedalling and always keep the weight on the drive, even when braking and stopping! I had to ride for 15 mile one day like this, very odd.[/QUOTE]
That sounds hard to keep pedalling always....

 

[summerdays]

I've never heard of a hungry chain, but I have heard of a thirsty one - dry and crying out for oil. Maybe she misremembered?

I didn't get very oily but it didn't strike me as rusty and not well looked after.

 

[raleighnut]

Sounds like a bent hanger caused it possibly or maybe exceeding the capacity of the rear mech.

As for the 'Hungry Chain' comment that sounds like something made up by a numpty to me, I've never heard it in 50+yrs of cycling (and fettling/building my own and others bikes)

 

[Ajax Bay]

I assume the chain was too short

If the chain is too short then the chain will not normally 'want'/be able to climb up to the largest sprocket. But if it had just managed it then maybe your assumption is dead on. Or maybe the B screw wasn't correctly adjusted and the guide pulley was contacting the largest sprocket. I'd disregard the 'hungry chain' comment - might be that with a dirty chain/chainring 'son' had experienced chain suck.

 

[summerdays]

She said she hadn't put it in big big combo, but it had jumped there. She did at least seem to know it wasn't a good combination. Hopefully she took it off to the bike shop rather than the son to sort, if he hadn't managed to fix it so far.