Rear Derailleur Hanger Replacement

[BobbyJones]

First time replacing one on my Vamoots.

Other than grease contact points and 40-50 ft lbs of torque for the bolt does anyone know of anything else I should know?

Thanks in advance.

[Cicli]

40-50 lb/ft?
Sounds like alot bit much.

Check the alignment. They are not always perfect.

[BobbyJones]

Whoops! lb/in - 5-6nm or so!

Thanks.

40-50 lb/ft?
Sounds like alot bit much.

Check the alignment. They are not always perfect.

[Peter P.]

Always have a spare derailleur hanger in your parts box.

[Rebel_Biker]

First time replacing one on my Vamoots.

Other than grease contact points and 40-50 ft lbs of torque for the bolt does anyone know of anything else I should know?

Thanks in advance.

A couple of extra screws is smart to have as well. I have broken some at well under the torque spec.

[ultraman6970]

Just tight that enough so it feels tight and the hanger is not moving. You really don't want to mess those threads up. Sometimes the torque specs for some screws and bolts are way off IMO.

[lhuerta]

...yes, the alignment of a new der hanger MUST always be checked upon installation, with wheel installed and with proper tool.

[BobbyJones]

Thanks all for input.

Lesson learned. I did order an extra hanger and bolt from Moots after the incident. So I'm covered for next time. After all these years I suppose it was bound to happen. I just thought it would happen in a crash, not from a hit and run bush.

Waiting for specialized parts is all the more reason to have a quiver of bikes to choose from!

Lou- I do most of my own wrenching but don't have alignment tools. I figured I'd install and if something was off THEN i'd go pro with it. Install went fine, maybe its the new chain (or a fresh start all together) but after a test ride everything feels better and quieter than before.

[Jaq]

Check to see if there's a local bike co-op near where you live. They might have an alignment tool. A couple years back, I sorta blew out my rear der and twisted the hangar. Did some looking and thinking and found a co- op called Bikerowave that had the tools. 7 dollars an hour for stand time and everything was jake. The nice part was that after that, I ended up volunteering there for about a year.

[lhuerta]

Lou- I do most of my own wrenching but don't have alignment tools. I figured I'd install and if something was off THEN i'd go pro with it. Install went fine, maybe its the new chain (or a fresh start all together) but after a test ride everything feels better and quieter than before.

Bobby, you will absolutely need the tool. There is no such thing as a hanger that does not need to b aligned upon installation regardless of whether ur dropouts r perfectly aligned....the correct tool is an essenential piece for ur toolbox. Remember that after u install a new hanger and clamp ur wheel ur dropouts will slightly move....it is this slight movement, unique to every bike, that a hanger manufacturer cannot account for when they produce a hanger, thus the reason that every new hanger must be aligned to match the frame it is installed on. Think of this as a great excuse to buy a new tool.

[oldpotatoe]

Bobby, you will absolutely need the tool. There is no such thing as a hanger that does not need to b aligned upon installation regardless of whether ur dropouts r perfectly aligned....the correct tool is an essenential piece for ur toolbox. Remember that after u install a new hanger and clamp ur wheel ur dropouts will slightly move....it is this slight movement, unique to every bike, that a hanger manufacturer cannot account for when they produce a hanger, thus the reason that every new hanger must be aligned to match the frame it is installed on. Think of this as a great excuse to buy a new tool.

I agree..the Park one is fine..$40-$60 new..lasts forever but all der hangers need tweaks now and again.

[Rebel_Biker]

I agree..the Park one is fine..$40-$60 new..lasts forever but all der hangers need tweaks now and again.

Not going to disagree with OP often. My park RD alignment is really cheap. I would score a used campy one online. The quality of the campy tool is so much better.

In fact, I will sell a like new Parks tool for $45/shipped if anyone is interested.

[oldpotatoe]

Not going to disagree with OP often. My park RD alignment is really cheap. I would score a used campy one online. The quality of the campy tool is so much better.

I have both..the problem with the Campagnolo one is lack of measuring arm..yes, you can use a ruler but Park one is much easier to use. The pivot on the Campagnolo one is much tighter, built better, but the park is easier to use/measure.

[JStonebarger]

I'll second (third?) the recommendation to stock up on replacement hangers, especially if the bike is unusual or older. Hangers are not standardized at all, and can be quite finicky.

I scored a NOS Guerciotti cross frame for my partner a few years ago. She loves it enough to ride it hard. Finding a hanger to fit that was impossible. Thank you, Dremel!

[lhuerta]

The Park DAG tool definite has a bit of slop, but the slop that exists is the same at every point in the rotation, so as long as u r gently pressing against arm during the rotation the measurement will b the same. The lack of horizontal measurement gauge makes achieving precision a bit trickier, making the Park tool an easier to use tool. It is seldom that I would disparage a Campagnolo tool (yes, I know, sacrilege) but in this case the R-tool may have run its course as there r better options available.

[Limonade]

Is the point of the alignment tool to adjust the frame? or the hanger itself? I thought the intent of the removable hanger was that it failed before the frame was damaged/bent. Sounds like the tool is to adjust the hanger, but can the aluminum hangers take much tweaking without weakening them?

Also, not to get too off topic, but why is it that some Ti builders choose to use a replaceable hanger and others just build it in? I had just assumed all ti or steel frames didn't have replaceable hangers. When i first read the thread i thought, replaceable hanger on ti?

[JStonebarger]

You're right that the hanger should bend before the frame. It should also bend before the derailleur.

The tool aligns the hanger, bending it as need be, to hold the derailleur in line with the rear wheel (and hopefully the frame).

[BobbyJones]

Devils Advocate time.

If the purpose of checking alignment and adjusting if necessary is to make sure the RD works properly, BUT the RD already works great, why bother?

I could understand if it was a dropout issue that can have a long term effect on axle / bearings, but if it ain't broke why fix it?

Or am I doing some less obvious long term damage?

You guys definitely know more about wrenching than me, but in 25+ years of riding geared bikes i've never had a derailleur not function properly due to unprovoked hangar misalignment.

[Mark McM]

In addition to poor shifting, there is another concern regarding a mis-aligned hanger: If the hanger is bent inward, the rear derailleur cage may contact the spokes (even if the limit stops are set correctly). Even if the derailleur seems to shift properly, you should check the cage/spoke clearance. If clearance is too small, you may want to check the hanger alignment.