Bent Derailleur Hanger ??

dee4life2005

I was out on a cadence workout ride last night and when in 39-25 I could hear a faint "ping, ping, ping" noise from the back wheel, but it went away when I shifted to 39-23, or if I shift to 52-25 (not that I ride cross chained like this). I immediately thought that something was up with the derailleur so shifted out the problem gear combo sharpish. It turned out to be because the derailleur cage was lightly brushing the spokes !! *edit - it's a triple chainset and I haven't tried 30-25, but I'd imagine this may make the derailleur cage brush the spokes even more *

As the limit screws have never been touched since they were correctly set, and that the bike has never fallen on the derialleur side, that this means that the derialleur hanger is likely to be slightly bent - doesn't look it from a quick glance.

If it's only slightly bent, am I lightly to have any problems if I remove it and gently persuade it back to being straight or should I just get a new hanger ?

ju5t1n

The easiest way to tell if it’s bent is to remove it and lay it on something flat. A good whack with a mallet can flatten it out. If that doesn’t work they’re not expensive to replace… http://gearmechhanger.com/

Monty Dog

If the hanger is replaceable, check the retainer screws are tight - it's quite common for them to come loose due to vibration.

dee4life2005

It is a replaceable hanger, so I took it off the bike. Checking against a flat surface I was able to tell it was bent, by about 2mm. Luckily a mate that has the same brand of bike has the same hanger and I was able to borrow his (new) spare. All sorted now.

markos1963

ju5t1n wrote:

The easiest way to tell if it’s bent is to remove it and lay it on something flat. A good whack with a mallet can flatten it out. If that doesn’t work they’re not expensive to replace… http://gearmechhanger.com/

I would never try to bend a hanger. Most are aluminium and a wack would create a weak spot. This could lead to a failure and a potential frame breakage. As you have said they a pretty cheap so err on the side of safety and replace.

dee4life2005

Bought a new one, and kept the old one. I did gently persuade the bent one back in to shape but it has been reserved for the emergency repair kit, as i wouldn't necessarily trust it full time on the bike especially as it's aluminium. For the size of the part £15 does seem a bit steep though .. But in the scheme of things better that than the frame i suppose.