Obliterated derailleur bracket

[anonymous-user]

Hi all

Just a quick random question. I was riding my 'new' mountain bike earlier. As I was slowing down to navigate a junction I shifted up a few gears on the rear derailleur and there was a huge bang and all sorts of bits of chain and gears flailing about.

I got off and checked the bike and found that the rear derailleur bracket was sheared clean in half.

Now, is this just something that happens, or has something else gone really wrong? I have never had this happen before, although I am not a hardcore cyclist. I don't want to pop a new one on and have the same thing happen again. It is an alloy bracket - am I better going to steel, of would a stronger bracket have just moved the damage somewhere else.

So, any ideas? Chain jumping and getting caught in the spokes? or just one of those things?

Thanks

Lewis

[Mr E]

The hanger should be replaceable; they are designed to fail rather than ruin the frame.

Last time I did one it resulted in a new hanger, a new chain, a new derailleur and a new middle ring.

[anonymous-user]

Indeed it is - well there are loads on ebay etc, I just need to take the bits of the old one off so I can figure out which specific one I need.

I did wonder if it was a deliberate weak link, as it is really quite skinny in the spot it broke.

Thanks

[bertieg]

as said, its a deliberate weak link. the trouble is, there is hundreds of different shapes. make sure you get the right one!

btw, normally called a mech hanger

[Rob_T]

On page 121 of the 'what bike bits have you just bought thread I said:

also bought a spare rear mech hanger kit. having just come back from a mtb holiday where a friend of mine broke his and didn't have a spare, i learnt a lesson that it is just worth carrying one round with you just in case.... it's as important as spare tubes and some missing links! fellow bikers be warned and take heed!!!!

[Mr E]

Skodasupercar said:

I did wonder if it was a deliberate weak link, as it is really quite skinny in the spot it broke.

Thanks

Buy two. Carry the spare. Doing this will ensure you never need it....

[anonymous-user]

Mr E said:

Buy two. Carry the spare. Doing this will ensure you never need it....

Too true! That would ensure that I never break one again.

[BOBTEE]

Check the derailleur is adjusted properly when it's all back together, maybe as you changed gear it got caught up in the spokes of your back wheel.

[amancalledrob]

BOBTEE said:

Check the derailleur is adjusted properly when it's all back together, maybe as you changed gear it got caught up in the spokes of your back wheel.

Yep, should be two screws to adjust the upper and lower limits of movement.

I had a similar thing happen to me once when I rode over a Sainsbury's carrier bag. It made me quite angry

[anonymous-user]

Just an update - Halfords stocked a replacement for £6.99 so very happy.

I checked the derailleur and it was a little bent, but bent away from the spokes and it doesn't look like it could have made contact with them. It seems reasonably adjusted, so still not really sure what happened.

Still, I will have my 8 mile ride to work tomorrow (on this bike for the first time) to try and break it again

[bertieg]

make sure you straighten the mech out if its bent. it'll likely never be the same again, but riding with it bent will not do anything any good