Bicycle Mechanics - Bent hanger on carbon frame

Hello,

I fell last week and bent the hanger on my carbon framed road bike. The derailleur is SRAM Rival.

I am probably going to take it to the shop and have them see what they can do, but was thinking about trying to fix it myself. Any opinions on the best way to deal with this would be very much appreciated. While I am somewhat mechanically competent, I've never done this type of work before.

I am thinking there has to be a way to bend the hanger back into shape, but I'm very concerned about cracking the frame in the process :twitchy:





Thanks!

Isn't that a replaceable hanger?
Is the damage limited to the hanger?

The hanger is torched. You can bend it back but you are just setting yourself up for failure. Metal fatigues after being bent back and forth. Just replace it and be done with it.

http://derailleurhanger.com/

Isn't that a replaceable hanger?
Is the damage limited to the hanger?

I don't know anything about hangers...so don't know if it's replaceable, but assume it is. I just don't know how to remove it, where to get a new one, and replace it. I've contacted the manufacturer, but haven't heard back yet. I assume each manufacturer has its own design.

I don't know if the derailleur is also bent, but will find out once I get a new hanger I guess.

The hanger is torched. You can bend it back but you are just setting yourself up for failure. Metal fatigues after being bent back and forth. Just replace it and be done with it.

you're probably right, I'm trying to find out where and how to get a new one now....

The hanger appears to be slightly bent. The hanger usually can withstand more than what the picture is showing. Park , Campi and other parts manfacturers make a tool that will bend the hanger back. The hanger is made from a softer material that is designed to bend and preserve the rear derailleur and the frame. Take it to your LBS and have a qualifued mechanic fix the problem. The bent hanger will effect shifting and possibly cause the derailleur to go into the spokes. Not fun. It is a job that will take just a few minutes but is necessary. While at the store you may want to ask them to order a replacement hanger. Usual cost is around $15.

Wheels Mfg. makes replaceable derailleur hangers for most frames. Go to their website and sort by manufacturer to figure out which hanger you need. You can check out their website here:
http://wheelsmfg.com/content/section/4/27/

It can be bent back, but like others have said, hangers are made out of aluminum and fatigue. Bending it back may result in a crack, meaning you'll need a new hanger any way. The only way to bend it back precesily is with a hanger realignment tool. Most shops have these and will bend the hanger back, but will probably run you $20-25 for the service, since they'll probably do a derailleur adjustment as well.

I'd just go with a new hanger. They are really easy to replace - use a 5mm hex wrench to take off the derailleur, and then a smaller hex wrench (usually a 2.5 or 3mm) to take off the hanger.

Hello,

I fell last week and bent the hanger on my carbon framed road bike. The derailleur is SRAM Rival.

I am probably going to take it to the shop and have them see what they can do, but was thinking about trying to fix it myself. Any opinions on the best way to deal with this would be very much appreciated. While I am somewhat mechanically competent, I've never done this type of work before.

I am thinking there has to be a way to bend the hanger back into shape, but I'm very concerned about cracking the frame in the process :twitchy:





Thanks!

That is an very minor bend, at best. Inspect the hanger for cracks after realigning. We do shop alignments for hangers on every tune-up. In the whole of last year we only broke one replaceable hanger, and that was only because the mechanic was being an idiot.

The whole point of replaceable hangers are so that IT bends instead of your frame, by that logic the same process used to realign will not damage your frame.

I'd just go with a new hanger. They are really easy to replace - use a 5mm hex wrench to take off the derailleur, and then a smaller hex wrench (usually a 2.5 or 3mm) to take off the hanger.

The new hanger must be checked for alignment as well. There's no point replacing a hanger when you haven't even ascertained it is broken and without even attempting to realign it.

take the replaceable hanger off first if you are going to try to bend it..
risk of fracturing your high $$ frame itself , is significant.

bike's brand dealer will have the replacement..

take the replaceable hanger off first if you are going to try to bend it..
risk of fracturing your high $$ frame itself , is significant.

bike's brand dealer will have the replacement..

This is 100% wrong.

He's going to take it off... and align it to what? The sky?

Have you even ever *done* a hanger alignment before?

The new hanger must be checked for alignment as well. There's no point replacing a hanger when you haven't even ascertained it is broken and without even attempting to realign it.

Agreed. My only point was that the OP seems to have an interest in doing the work himself, and in that sense it would be more cost effective to go with a new hanger.

The last time I bent one I took it off and layed on the garage floor and whacked it with a hammer. It was good enough for my cheap second hand 8-speed bike. If I had a bike as nice as yours though
I don't think I could live until I had done what these guys are telling you and that is put a new one on.

I fortunately stay away from Carbon frames . so a popcorn moment..

[NB Ive been working on bikes for 50 years, 'Professionally' thru a big chunk of the 80's, early 90's]

the hanger started off flat.

with a flat steel surface and a hammer it can be flattened again.

[want no marks? , a metalsmith's suggestion: polish both surfaces]

then you get the dropout alignment tool from your bike shop pro tool kit..

Campag tool R, part of their complete tool set 3380, for 30 years..
and tweak the replaceable hanger ..

It is also a tool supplied by other makers Shimano, Park, etc.
as indexing needs that parallel plane alignment.

If there is not much mis alignment the bike shop alignment tool will be sufficient.
Yup new part will need shop alignment too .. not a home kludge job.

The hanger bracket isn't expensive enough to order online, shipping will eat you up. You can go to any bike store and they will order you one though it's best to go the dealer who carries the bike brand. Buy the bracket, put it on with a hex wrench, if it shifts ok through all the gears, you are fine. If it doesn't, bring it to any bike shop and they will align it to the wheel with an alignment tool.

Thanks VERY much to all the replies.

I found a replacement hanger for $20 which I ordered and will try to install and align myself. I'll try to straighten the old one and keep for a spare. I'm hoping I didn't also bend derailleur and will check that out once I take it off for the repair.

thanks again to everyone!

once it's on , if the indexing isn't crisp, out of luck and serendipity ,

I'd still have the LBS do the checking with the hanger alignment tool,

with it, it's a quick job. good luck :thumb:

Agreed. My only point was that the OP seems to have an interest in doing the work himself, and in that sense it would be more cost effective to go with a new hanger.

a new hanger needs alignment too

even if you did bend the derailleur you can ususally bend those back into place by hand. i would buy a new hanger though, it's a 5 min job to replace it yourself.

Now that you have a replacement hanger coming - spend a few extra $ and get the original hanger straightened (preferable by using the proper tool and a good mechanic). When the new hanger arrives get it checked as well. That way you will have a ready-to-go replacement hanger. I have come across a pretty high percentage of new bikes with not aligned hangers and new replacement hangers that are not straight. Standard procedure on new bikes and new hangers -- put the hanger alignment tool on it , check it out and make it right.

For home repair when you don't have the tool you can use another rear wheel that is in good shape (true).
Remove the der. and thread the extra wheel axle into the hanger. The rear axle is normally the same thread gauge (10X1mm). Use the wheel as a lever to bend the hanger until the wheels are parallel. This is how the tool works.

They are on the bike to save your derailleur.

I had a hanger break on me a few months ago, Nowhere locally stocked the one I needed, and quoted $50AU to order it in so I ended up ordering 4 of them online from 2 seperate places, eBay (Israel manufacturer) and http://wheelsmfg.com, one arrived in 2 weeks, the other in 4 weeks, $25 each, so $100 all up including postage. Now I have a spare with me whenever I ride (so next time I don't have to walk 10km in mud), plus a few more at home.

sorry, dupe

Make sure to ask the price of the alignment my LBS wanted $50 for an alignment, no mention of derailuer adjustment. I doubt that an adjustment was included since I was building up an old frame and I didn't have the shifter cable on the bike yet. I purchased the alignment tool for about $50 and have used it 4-5 times already.