# Aligning a derailleur hanger: do you really need the pricey tool?



## aBicycle (Jun 13, 2012)

Or is there a cheap way to do it?


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## SenorSerioso (Apr 22, 2011)

The tool threads in to the hanger and pushes the alignment face square against the face of the hanger. Then there's the lever arm and a reference guide showing you where it is in alignment with the wheel. 

Pretty simple tool, I think accuracy will make this one a tough one to replicate, though. Those hangers can be finicky. I'm interested to see your results if you do try it.


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## wschruba (Apr 13, 2012)

Can you do it with a homemade tool? Sure, do a search for one, there are a few floating around.

Is it worth it considering the price vs. accuracy of the professional tool? I don't think so. If you are dealing with 10 speed clusters, eyeballing it can be difficult, but not impossible. The proper tool works on any bike, and quickly at that.

If you are deadset on not spending money, shove the long end of a 5mm hex into the derailleur mounting bolt, hold it in with force, and bend. It is, at best, just as good. At worst? You damage the derailleur.


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## Slash5 (Nov 27, 2011)

Been thinking the same. Someone on here said that a normal threaded axle has the same thread as the derailleur so can use that as the pivot.
But I was in Lowes just yesterday and was looking at square tubing. The tubing was anywhere from $14 to $25 depending on steel or aluminum.
I'm sure I can find it cheaper but it's looking like building a half assed one is going to run close to the $25 mark. Wondering if it isn't worth paying the $59 for the proper one.


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## Birdman (Dec 31, 2003)

I've straightened hangers with a very large crescent wrench, but it's a real PITA. Hangers tend to bend in more than one plane, so you'll need to tweak and eyeball it several times.

The Park DAG-2 is very fast and accurate. You adjust and measure with the same tool. I just waited for a sale and bought it for less than retail. Money well spent, IMHO.

JMJ


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## bing! (Jul 8, 2010)

My local bike coop has one. Almost every major city has a bike coop. I pay 7 bucks an hour to use all their tools. 

But still, for the occasional hanger tweak, I clamp a 12 inch steel ruler on the hanger and eyeball the ruler against the cassette at 12 o'clock and 9 o'clock, peering at the ruler from above and behind the bike while its on the stand. Then I tweak with a crescent wrench. 

It normally takes 3 to 5 adjustments and no longer than 5 minutes to do the job.


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## GTscoob (Apr 27, 2009)

bing! said:


> My local bike coop has one. Almost every major city has a bike coop. I pay 7 bucks an hour to use all their tools.


This. You might even look into college bike shops and offer up a 6 pack.

You could easily make your own hanger alignment tool but I doubt the cost savings would be much compared to buying the Park Tool version.


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## JPaul (Sep 18, 2010)

I guess it depends on how often you need to re-align.

I've used the front axle approach with success with drivetrains up to 8-spd rear(remove front wheel, set QR aside, and thread the whole wheel into the derailleur hangar. Use rim for leverage and reference points -> can do a good deal of fine tuning ) . Just haven't needed to try it on a 9 or 10-spd rear in several years of riding them, so investment not worth it In my case.


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## shiggy (Dec 19, 1998)

aBicycle said:


> Or is there a cheap way to do it?


Correctly/accurately? 
No.


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## -Todd- (Jun 13, 2011)

What's the cost of a decent derailler alignment tool? 100? 125?

I find that if you need to use something like that 3-4x, it's worth the cost to own. Cheap isn't always good, but good tools always pay for themselves


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## Shark (Feb 4, 2006)

Park tool can be found under $60....I bought one, totally worth it for perfect shifting.


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## dogsridewith (Oct 31, 2012)

For by-eye--Get best view, by bike upside down, or reear-wheel-high, if on stand. Use different gears to view with cage parallel and perpendicular to chainstay.

The top of a broken/junk deraileur can give something to grip to bend the hanger.


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## car_nut (Apr 5, 2010)

I use the second wheel method described above. Easily as accurate as the Park Dag.


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## skeered1 (Jul 30, 2007)

I've mentally argued this myself since my GT Sanctions replacement hanger is $55 a pop. We all know how finicky this hangers are after a crash and how annoying it gets. Once I was chatting w/ another rider on the trailhead while he's making adjustments with his derailleur alignment tool so I had a good look. My DIY version was guna cost around $30+ w/ some work/assembly required and not nearly as neat & user-friendly as the Park Tool. So I got one shipped-free - Park Tool DAG-2 Derailleur Hanger Alignment Gauge - AAWYEAH Bikes and Bicycle Parts

You can definitely go cheap as what other folks here recommend. I've gotten lucky w/ a pair of pliers once. The Park tool is quick, easy and accurate. For me, peace of mind is priceless.


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## Slash5 (Nov 27, 2011)

Finally just ordered one. BikeWagon has 20% off so about $48.


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## ariesadel (Nov 18, 2012)

Slash5 said:


> Finally just ordered one. BikeWagon has 20% off so about $48.


I have just ordered one from BikeWagon as well. With the 20% coupon, the price was more than $10 cheaper than from Amazon.


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## ozigoo (Mar 14, 2012)

I made my own tool using a length of 50x25 densified wood, an M10x75 fine pitch bolt, 10 or so M10 washers and 2 nuts.
Drilled a 10mm hole in the wood, greased and inserted the bolt with 1 washer, stacked a bunch more washers on the other side and locked the two nuts against each other to allow it to swing on the bolt.
Could add some kind of gauge to it, but I can get the job done easily enough with a combination square.
Sorry for the lack of pictures, down to a lack of posts.


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## Metamorphic (Apr 29, 2011)

You'll be glad to have the DAG2. I think you'll find, as I did, that you'll be reaching for that tool first when there's anything even a little bit hinky with a bike's shifting; far more often than you expect. Any other playing, adjusting, tuning you might try is wasted if the hanger's tweaked. For me, checking hanger alignment has become part of the normal pre-race or pre-big-ride prep I do on the family's bikes.


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