Help with rear derailleur - is this thread bent ?
 

Hei all,

had an accident last week, which ripped apart the rear derailleur (Shimano Altus) of my mountain bike. :notamused:
Just bought another one (Shimano Alivio) and am replacing it.

But when placing the new one in place, I noticed that the little plate on the frame with the thread is leaning towards the cassette. See pic. Has this plate really been bent in the accident or is it supposed to be like this???

I'm almost sure it bent in the accident because I cannot adjust the new derailleur, but I just wanted to confirm that before I get a hammer and a wrench to try and bring it back to normal :crash:.

Thanks!!!

http://bikeforums.net/attachment.php...hmentid=300957

Yes, its bent. It should be parallel with the cogs on the cassette. Stay away from the hammer, that won't help and will probably do more damage. There is a proper tool for fixing this that threads into the hanger and your local bike shop probably has one. I have had success with using an adjustable wrench closed up tightly against the sides of the hanger and slowly bending it back. Depending on the type of material the hanger is made from, it may just snap off. In that case the frame is trashed, because it doesn't look like a replaceable hanger, unless your ok with using one of these http://problemsolversbike.com/produc...ailleur_hanger

sorry to hear your accident, for i seen that your hanger sorry is bent. and need to be fix by LBS which got special tool to straighten up. please dont use HAMMER and WRENCH is just making worse, just leave the pro to fix it.

+ 1 on having it done by someone with the right tool. If the hanger does snap off you may be able to replace the derailleur with one which has a claw-type mount. Something like the "Tourney Magarange" one on this page should work at moderate cost: http://sheldonbrown.com/harris/derailers-rear.html

EDIT: Here's another one: http://www.amazon.com/Shimano-Tourne.../dp/B003ZMH69S

Thanks for the help!
No hammer, no wrench :) I've borrowed a tool to fix it and it's now parallel.
BUT there is another problem... when the derailleur broke and bent the frame, it also messed up with the thread :(
So now the new derailleur doesn't get attached firmly because the thread is gone...
These look good for my case!! I didn't know they existed.
I'll see if I can find either one and try them out.

I really don't think the thread can be fixed...

Well, in the last case if nothing works, I guess I'll just use a strong epoxy glue on it =P

That's almost surely fixable.

Tweaking the hanger back into alignment is only a $15.00 or $20.00 job. It may be necessary to run a tap through the threads from the back side. In the worst case, the derailleur mounting hole can be drilled out and a "drop out saver" installed from the back side.

A dropout saver will solve your problem. Any decent bike shop should be able to install it for you and they can do the alignment at the same time.

http://wheelsmfg.com/dropout-saver.html

Retro Grouch beat me to it.

More new fancy things I had never heard of :) Thanks guys! One of these dropout saver would definitely solve my problem... Hopefully I can find them here.

re-tap your threads should work, or can you change your hanger?? a couple month ago i got accident and my hanger bent, i just replace it with $4 work perfectly.

No, the previous recommendation for a dropout saver is the best solution. Both the threads and the hole itself would have suffered a severe amount of distortion from the initial damage as well as rebending. I don't think it wise to depend on rethreading to provide a reliable solution in such circumstances. It might work, but is it wise to take a chance on reoccurence?