How to detach Shimano derailleur from hanger

[vitataxman]

I have a Trek Navigator 50 with a Shimano Tourney derailleur (shown in photo). I would like to repair the derailleur hanger which appears to be slightly bent. All the videos/tutorials I can find show simply unscrewing a 10mm bolt to detach the derailleur from the hanger. There does not appear to be any obvious way to access the bolt which holds my derailleur to the hanger. The plastic cover of the derailleur is not removable as far as I can tell. I can remove the hanger+derailleur assembly from the bike frame (have not done this yet) and then maybe figure a way to detach the derailleur from the hanger; is that the proper way to proceed? Hope I'm not missing something obvious.

 

[fritz katzenjammer]

It’s the exposed bolt at the top of the derailleur. It takes an M5 Allen key.

the black bracket is part of the derailleur, the bit you want to assure is straight is the silver part it is attached to.

 

[vitataxman]

Attaching another photo. The black bracket bolts on to what appears to be the frame of the bike. Is that something that can be safely bent?

 

[fossyant]

You've potentially got two bent bits, the 'silver' hanger and the top metal bit of that Mech. You can bend them back, but I'd suspect it's the black bit on the top of the mech that's bent - usually metal on these Tourneys.

 

[Ajax Bay]

Shimano Tourney derailleur. . . to repair . . . slightly bent.

There does not appear to be any obvious way to access the bolt which holds my derailleur to the hanger. I can remove the hanger+derailleur assembly from the bike frame (have not done this yet) and then maybe figure a way to detach the derailleur from the hanger; is that the proper way to proceed?

This is a steel frame and there is no separate hanger!
Remove wheel.
Remove RD
Straighten “frame-integrated” rear derailleur hanger in situ and steel will take the bend (whereas bending (back) a separate aluminium hanger is a temporary measure only.
(A rear axle is the same thread and diameter btw and I use a broken one if this needs doing (steel frame).)

 

[T4tomo]

This is a steel frame and there is no separate hanger!
Remove wheel.
Remove RD
Straighten “frame-integrated” rear derailleur hanger in situ and steel will take the bend (whereas bending (back) a separate aluminium hanger is a temporary measure only.
(A rear axle is the same thread and diameter btw and I use a broken one if this needs doing (steel frame).)

the issue with that is that if the integrated hanger is lined up straight (which it probably already is now btw) but the top bit of the mech is bent, the indexing will still be all to cock.

it might be agricultural, but maybe the OP is best off just bending the tourney mech back until it looks straight and seeing if that works (or gte a new tourney rear mech to fit to the straight integrated hanger.

a hanger aligning tool is useless in this scenario as its the mech that is bent (probably)

 

[raleighnut]

That looks to me like a mech with integral hanger (built in) so not 2 separate components.

 

[Ajax Bay]

 

[All uphill]

View attachment 751881

Available new for around £8.

I'd get the hanger straightened and stick on a new rd.

 

[figbat]

You need to verify if the frame part is bent, or the black part of the derailleur. My money is on the derailleur which can either be bent back (I have done this successfuly with kids' bikes) or replaced.

 

[vitataxman]

Yes, the frame does not appear to be bent. What advice do you have for how to safely bend the integrated hanger on the derailleur? I can clamp the free end in a vice, but there is not much remaining hanger area grab on, and I'm nervous about using the derailleur itself to apply torque.

 

[Ajax Bay]

What advice do you have for how to safely bend the integrated hanger on the derailleur?

Buy a new one. V inexpensive.
That first element of the RD is not an "integrated hanger" - that's the dangly bit which is part of the steel dropout.
Trying to bend that (black bit) will likely damage its link to the rest of the RD (because so difficult to secure to get enough purchase with very short leverage).
Also difficult to know, after some bend is achieved, whether it's "right" without refitting etc etc. Y patience (and expertise) MV.
https://www.decathlon.co.uk/p/rear-derailleur-6-7-speed-shimano-tourney-ty300/_/R-p-X8523798 £12
https://www.ebay.co.uk/itm/234478459494? £7 (free P&P)
Not specific recommendations.
Maybe @All uphill can give a better link.

 

[vitataxman]

Makes sense. My first instinct is to try and fix, but as you point out, the replacement is inexpensive, and the bend/fit/test iterative process would likely be frustrating and inaccurate. Thanks to all for the advice.

 

[figbat]

Buy a new one, keep the old one and have a go at fixing it. If you do you have a spare for when the new one gets trashed!

I recall I have just tweaked them by eye on the bike; they bend pretty easily.