iamLefty

Will be replacing the dropout of my bike. A few questions.

1. Do i need to grease the threads of the dropout screws and the rd? And do i need to grease the upper part of the dropout as well?

2. How tight should the screws and the rd be? First time doing this so i am very careful.

Russ Roth

The screws sometimes have a litle blue loctite on them, I've never bothered greasing them, same with the rear der bolt and have never had a problem with things coming undone at a later date. The screws usually use a 2.5 or 3mm allen wrench, so make them snug but don't use a lot of force. No idea the actual amount but with the 2.5mm wrench especially you can see the wrench on a longer t-handle start to lightly twist, that's more than tight enough.

iamLefty

Oh that’s loctite? Yeah, the screws have them. Had a real hard time finding a replacement dropout for my caad8. Almost bought a china made one. Got no t-handle but i got long bondhus hex wrenches. Hey, thanks! I wanna be extra sure before i proceed.

It’s easier to do this with chain removed, right? My shimano chain does not have a quick link. I didn’t bother to put one since i just clean the chain while on the bike. Got a couple spare links here.

maddog34

there is no need to remove the chain from the bike... just take the wheel off the bike and take the chain off the chainrings onto the bottom bracket. Place a rag around the bottom bracket if the paint is in great shape to prevent scratches. the Derailleur will now have no tension on it from the chain.
Remember to engage the Derailleur stop/B-screw with the Der. Hanger stop. i mention this because someone was trying to mount an expensive derailleur WITHOUT considering those stop tabs a few days ago A bent B-screw will be the result of NOT paying attention to things.. or even a ruined Derailleur. you may know about the B-screw... the next reader may not.....

https://image.ibb.co/g3kfJQ/IMG_5339.png

iamLefty

I’ll remember that. Thanks!

dedhed

Good reason to buy a couple spares.Might have better luck if you called it a "derailleur hanger" which is what it is called. Best practice is to get it aligned after installation.

SJX426 

Yup. The hanger attaches to the drop out.

Kontact 

Keep in mind that the screws aren't structural - they are there to locate the hanger - your axle and quick release are what really hold it is place. Do all you alignment checks with the wheel in place.

Barry2 

Just to add a little detail to the comment above.

Replaceable derailleur hangers are made of aluminum for two reasons.
1. If you hit the rear derailleur (crash or drop bike) the hanger will bend and not the frame.
2. You can bend the hanger using a “Hanger Alignment Tool” to adjust and ensure the rear derailleur is aligned with the wheel.

New hangers are not pre-aligned and should be aligned at the time they are installed to the frame.
You can’t eyeball this, tolerance is only ~3mm at the wheel rim.
Failure to align the hanger can result in poor shifting that you just can’t adjust out.


All the best

Barry

iamLefty

The hanger on the bike was straightened with an alignment tool 2 yrs ago in a bike shop. Bike fell due to strong wind. It’s always at the back of my mind to replace it when i find one, for peace of mind. I was always worried it might just snap. The bike shifts ok, but the hanger is not perfectly straight. Anyway, i found a replacement a few days ago and bought it.

Not familiar with new hangers. Hopefully this is not one of those new hangers
you mentioned since i don’t have an alignment tool. This is a Union GH-192. I’m hoping i just need to install it without any need to align it.

iamLefty

Here’s the hanger on my bike and the one i bought.

Barry2 

Align it, don’t align it, your choice. (BTW it’s all hangers that should be aligned)
But at least now if you have shifting issues, I hope you won’t buy a new derailleur.

Barry

iamLefty

Dang. I thought i just need to put the new hanger, then the rd and wheels, do some tune up and that’s it. Didn’t know i need to do alignment check. How do i align this though, would i need an alignment tool? Don’t have one. Btw the screws are bolted from the inside of the frame.

dedhed

"Eyecromiter" is usually "good enough" up to about 7 speed. Beyond that the tool is pretty much required.

dedhed

Google derailleur alignment gauge. there are cheaper and homemade solutions as well, like a wheel

​​​​​​https://www.parktool.com/en-us/produ...nt-gauge-dag-3

Barry2 

If I turned up at my local bike store with the derailleur removed and needing the alignment only, they charged me ($20 cash in the beer fund I suspect) and did it on the spot while I waited.
If you needed the derailleur adjusted as well, then they wanted to keep the bike.

I now own the tool and check/align hangers for me and my buddies. Cost is usually IPA or coffee.
My 11 speed and 12 speed bikes just need to topple over on their righthand side to require a realignment.
The tool has more than paid for itself.

Barry

BTW - As with all tools there are cheaper options than the name brands, for infrequent use these will likely be fine.

iamLefty

I paid the bike mechanic around $10 when i had my hanger aligned. It’s cheaper here, most shops just charge $1 for a tune up. I’ll probably end up bringing the bike to him again.

Anyway, i’ll go check out some alignment tools first. Is this easy to learn?

Barry2 

Yes it's easy to do.
Just go really SLOW and don't over bend the hanger.
Being aluminum they will only take so much bending.

Barry

smd4

Assuming you mean "easy," then yes. Watch a couple YouTube videos. You'll thank yourself in the end for learning how to do it yourself.

Don't let specialized tools scare you. That's why they were designed--to make jobs easier, not more complicated.

iamLefty

If i see a decently priced one, i just might buy it and learn this thing.

Barry2 

Cheap tools abound


In my posts above there are clickable links (text is pale blue and underlined) did you miss them?

Barry

iamLefty

I’m a bit new to this, why i’m both excited and a bit scared to cause some damage. I usually just bring the bike to a mechanic. But now i wanted to learn on my own, make this a new hobby. I’ll see if i can find a decently priced alignment tool.

iamLefty

Just saw them. I’ll check ‘em out.

icemilkcoffee 

Come on. Just how often does a brand new hanger need to be bent and aligned? Just slap it on and go.

smd4

He can probably just re-align the hanger that's currently on the bike.