Newsflash bike broken

[macp]

Lovely morning enjoying my ride in when suddenly about half a mile from work there was a snap and brief locking of the back wheel wtf !!

On looking down I discovered the derailleur hanger had snapped. Seems like it has not taken out any spokes or caused damage to the frame.

Thats the cycling news for today

 

[Globalti]

Has it been bent and straightened? They are made from very brittle crystalline alloy and designed to snap sacrificially to save the frame. The alloy work-hardens if you try to bend it and will snap.

 

[macp]

Has it been bent and straightened? They are made from very brittle crystalline alloy and designed to snap sacrificially to save the frame. The alloy work-hardens if you try to bend it and will snap.

Certainly not by me and I dont remember it looking like it had been tampered with when I cleaned it Sunday. Wife says the muck was holding it together and then I cleaned it

Anyway its going into the LBS later today and I will take the car for a day or two. Should have placed this in mundane news

 

[Globalti]

It's a 5 minute job to replace it yourself if you can get the right hanger. Buy two and keep one for spare.

 

[macp]

Its done all fixed but now im wondering if I caused it. I tend to ride on the big ring and im usually on the first two cogs at the back when moving off from standstill. Could this have been the cause ?

 

[Globalti]

No, unless the chain is really stretched tight when you are in those gears. Equally likely the bike got laid down or fell over on its right side, damaging the hanger. How was the shifting before it snapped?

Big - big is not recommended because you are forcing the chain to change direction abruptly, twice, which will wear the chain very fast. It's called cross-chaining and it's a mark of lack of mechanical sympathy with the way gears work.

 

[macp]

Thinking about it I had an altercation with a bin and the bike fell onto its right side but there seemed no damage and the shifting seemed fine. Regarding mechanical sympathy thus the question regarding whether I was likely to be causing any problems. I take issue with your comment regarding mechanical sympathy as generally I am very sympathetic to my bikes mechanicals and do most jobs myself. I was aware of certain positions of the chain in relation to the cogs that may cause undue stress again hence the question. I dont see the problem with asking a question in order to learn.