How To Make A Derailleur Hanger Alignment Gauge Tool 

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You are truly a worthy successor to Sheldon Brown(RIP). Learned tons from your videos

So great RJ! Local recycler charged me $0.65 for sweet square aluminum post from a 10'x10' tent. Bolt Depot online had variety of correct bolts and drill bit you specified. local metal artist cut the square tubing, drill presseded the holes, and even sanded down the edges for my largest spend - $10. Built two tools, one for me and one to give to my local bike tool co-op; Community Cycles. All is good in the bike world.

I tried this and it worked perfectly. I couldn’t find a bolt with that thread so I used an old axle. Thanks for the idea appreciated.

Mate, this is exactly what I was looking for. I looked at buying one but the price is a little more than I was willing to pay. I also just happened to have some square bar here that I almost threw out. Brilliant idea so thanks very much for putting this up.

RJ’s videos on bicycle maintenance and repair are among the best. His solutions, easy to understand and practical, have helped solve a number of my bike issues. This video on how to make a derailleur hanger alignment gauge tool is another great help. It solved my bike derailleur hanger issue with minimal cost. Thank you RJ.

Found your video when I was looking for the thread size of hanger as I was just going to bend it but didn't want to stress the threads. But you made the tool manufacture so simple- why not be more accurate? The money I saved on the tool I used to buy a small bench drill press- something I've needed for years. So now I have a repaired bicycle, home-maid tool, and can actually drill straight holes! Thank you RJ!

Love your work, these tools that you don't need often and can make yourself are awesome

RJ is a real hero. Because of him didnt go to the bike shop anymore for the last few years, and built 4 randonneurs in the meantime. Gr of the west of Ireland

RJ’s videos on solving bicycle issues are among the best. His solutions, easy to understand and practical, have helped solved a number of my bike issues. Making an improvised derailleur hanger alignment tool is one. As I do not have the necessary tools to drill holes on metal post, I used ready cut PVC pipe following RJ’s idea. Though it’s a little cumbersome to use the improvised alignment tool I made, the hanger has been aligned anyway and gear transmission has become smooth. Thank you RJ for your simple but great idea. 👍👍👍

My weekend project. I think this will allow me to love my bike again. So many problems coming from out of alignment hangars that I have just now today learned about. I crashed this bike 16 years ago and never can I find perfection from the rear mech. Thanks, RJ I found this video super helpful, especially to see how the tool was used!

My dude, I really appreciate your videos! Making maintaining my bike easy and affordable! I really dislike how cycling has become so expensive for quality maintenance. I always rather do my own repairs/maintenance and these videos are a huge help to do the more technician skilled repairs.

Thank you so much! You made this a very simple project that worked perfectly, and saved me a few days ride time and a few bucks to boot.

Thank you so much for this video. Pretty much followed it exactly. Instead of the solid tube steel I found some "1 in. x 36 in. Zinc-Plated Punched Square Tube" at Home Depot. It comes with holes in it already and I only needed to increase the diameter of the holes a little. I used one of the levels at the store to check the tube for straightness. I recommend doing this while you're at the store. Thanks again.

Thanks RJ you just saved me $55. I was just about to order one when I decided to check youtube to see how they work. I watched your video on how to use the tool and when you mentioned you were going to do a DIY tool video I searched it up very simple and straight forward.

Nice simple alternatives thanks for those, I will be using the spare wheel idea later today and looking at making the tool later. Some vids like this one deserve the option of more than one thumbs up.

Just wanted to leave you a note thanking you for the alignment tool specs...I thought my derailleur was just a wee bit out of alignment...I built a tool following your specs just for fun (identical, in fact) and learned that my derailleur hangar was, evidently, pointing somewhere near the landing site of one of the Apollo missions. It's fixed, and the shifting is now seamless. Many thanks!

This is so awesome I'm probably going to make a couple so I can give one to a friend. Anyone with a bike that is picky about their shifting should have something like this. This is perfect for someone who would have to do this occasionally but I can still see how the sliding bar on the Park Tool version would be better for an actual bike mechanic that would do this all the time.

And on and on....you still keep them coming RJ. I really like using a measuring rule instead of installing a slide. Keeps the device simple and easier to grip and to use it as a lever to actually adjust the hanger.

Hey RJ. Thanks on this one. I just made one using a 25 mm sqaure tube. I could not get m10x1 bolt so took an old rear hub axle, cut it a milimeter above the end of the thread on the inside where the locknut could stop. Used two cones and locknuts on both ends and it works perfectly. The most important thing is this drill the holes perpendiculary. They cannot be skewed. Otherwise this tool is pointless because it won't be on the same parallel plain as the hanger when screwed in. However I found dificcult to allign my hanger. I bend it really firmly, it flexes but returns back to the original shape.

Great video, thanks. I made the tool this afternoon, straightened the hanger and fixed my shifting problem. Note: I used it on a replaceable aluminum hanger, not a steel frame bike with an integrated hanger. I assume there a limited number of times you can do this without damaging the hanger, but I didn't have much to loose since I'd need a new hanger anyhow. It was only out a couple millimeters.

Thanks Rj, great as always. I bought the real tool a while back based on your glowing reviews and found only one bike in my fleet of family bikes was close to true. I would've totally tried tool make one like this. clever sir!

Just made one and it’s spectacular! I used a 3/8th drill bit and it was perfect. Thanks for the idea

Thank you, thank you, thank you for this video! I made one based off of this, and have used it on 3 bikes so far, fixing bad shifting issues on all of them.

Necessity is the mother of invention, as they say. So simple, and SO much cheaper than buying the ready made tool. Well done!

Thanks for making this video. I have rear derailleur alignment issues, and I am pretty sure it is a bent hanger. I'll try this out some time in the next week.

A simple solution to a simple problem. It's accurate enough for me to see what my problem was, it's fixed now. I would have either bought an expensive tool or put it into a shop, this was way more satisfying. Thanks. And I have a tool I am happy to lend out too.

I suspected my hanger was out of alignment (though I don't remember it being knocked from new) so I made a tool similar to this. it was out by a mile but the tool did the trick. Absolutely Brilliant! Thanks.

Great job R.J. I just got a new ebike Alite 500 from Luna Cycles, and now I'll have an inexpensive way, to keep my derailleur aligned. Thank you!

Man Derailleur hanger is so huge problem and your vids are exactly what I looked for. Thank you so much for this!

Thank you so much RJ. I made one today and saved myself over £80 UK on buying a Park Tools one. At the moment, I'm using an old 10mm QR wheel axle (with cones, spacers and stuff) but I'll get a proper bolt with nuts and washers.

I've always eye balled it to get the hanger straight but is perfect. Thanks RJ

Just made my own version from materials laying around my workshop. Couldn’t find a 50mm bolt so I used an old derailleur screw. It meant I couldn’t move the arm all the way to the 12 o’clock position as the QR screw was in the way due to the shorter length of the screw, but I could get it as far as 10 o’clock which was sufficient to measure the vertical alignment. My gears are now shifting perfectly after an accident which bent the hanger quite seriously. Thanks for the video, it was exactly what I was searching for ⭐️⭐️⭐️⭐️⭐️

I have all the tools to make one this morning. I have ordered the Park Tool DAG-2.2. But Wiggle is very slow in shipping even though it said "express shipping". So thank you for this video as this will get me back on the road. My gear shifting is not too bad, but it could be better. This homemade tool will 1000% help me this morning.

made mine today exactly like that, works like magic thank you for your time to make this awesome video

The best wonderfull tool i haven t seen ever in youtube thanks a million for your video. From morocco

That's a great hack RJ appreciate all your videos, I bought a used 2009 Gary Fisher and used a lot of your videos to tune her up, she rides a lot smoother than when I bought her thanks.

I did this tonight with a rear wheel quick release axle and hardware and a piece of square steel tube from an old mailbox. It works and it's easy!

Thanks for giving me great inspiration!! I just needed to adjust my hanger.

Hey Bike Guy this is a great tool to make for exact checking and bending the hangers. Slower in use the the Park tool but easy to make and for the one or two times in the year i need it - just great. I will make on on the weekend and after a little Overengineering i'll be happy with it. Thank you for the inspiration, for saving money and most of all for giving me a reason to start the old welding machine again to fabricate a tool.

awesome video, I made 2 of them and painted them cast iron grey. The hardest part was putting the rear derailleur back on. I couldn't get it to thread into the hanger. I ended up having to back out the stop screw all way and then thread it in. after I tightened it, I turned the stop screw until half of the threads were in. It already shifts better and I haven't reindexed it.

Thank you for the great video! My son and I are headed to Lowes to get our supplies.

So far, the best bike maintenance channel. Best regards!

Ok, ex bike shop mechanic from the 80's-90's here and I just put on a new Ultegra 10-speed R Derailleur, new Ultegra chain, cleaned the cassette cogs, cleaned the Ultegra shifters, and rerouted the cables. After adjustment the bike shifts like crap and is really sensitive and touchy. The hanger alignment looks a little off and I was just about to buy a tool and ran across this video. I'll have to make one of these. Great info!

Excelente herramienta. Great tool...

I made it using steel tube...working perfectly for my bicycles....thanks a lot.😊👍

I was just considering making a tool like this. Great timing. I think it is advantageous to have a bit of play in the hole so that if the axis is not perpendicular to the face plane, it doesn't matter. Thanks

It works great. I'm getting my 80s Dawes Galaxy ready for a summer of touring. It's running true and I saved myself £60. Thanks

Simple yet effective. RJ the Bike Guy does it again.

Great video and what a great project. I just learned about this problem and about this tool. I could get one, but I'd rather build 2 or 3 of something for less than the price of one item. It's always nice to have an extra, a backup or to make one that is a different size, length, weight, color or of different materials or has more or fewer features. Now if I find a bike that shifts poorly, I'll know to check for a misaligned hanger and I can even fix it myself.

you demonstrate an uncanny imagination and creativity ( translation: awesome dude)

Love it, have all the materials in our shop. As luck would have it I was given a bike with a bent hanger a rew days ago....thanks

Thanks for that! It's just what I need. I'll make one tomorrow! Also. many thanks for all the knowledge you've passed on to me over the years, it's been invaluable. Vic in the South of England.

Hello RJ i have been able to make most of the tools you have made thank you for this one i have saved a bunch of money love your videos.

Just awesome! Willl make one and try to finally fix my Deore deraileur to work decently. It really suck. Brand new on a brad new bike but never worked properly. The 6-year Acera on my Rockhopper in the other hand, is still just perfect, even after lots of sand, mud, rocks and dust. And the bike never went to a shop for any maintenance.

Muy ingeniosos todos tus inventos!!! Muy instructivos y educativos!!!Saludos desde Argentina.

Great video, I like it. Just made your headset removal tool for a khs 1996 Montana descente renovation.

Great videos, right to the point, I learnd so mutch watching them. Thank you. Greetings, Mirko

Brilliant, well done and thanks for this nice tool to make...was just about to buy one...but made my own...works perfectly...

Pure joy to watch - thank you!

Awesome video! Gonna make one of these for my bike. Don't need it yet but will be great to hsve when I do need it. Thanks!

Made it, used it, brilliant. Thanks RJ!

Great video man! A must to have tool for any mountain biker

I made it. It was a little lose but I pulled it to the same tension when measuring. But for fixing a commuter bike it worked great! Thanks!!!

Im totally making this tommorow.Thank you dude.

Many thanks from Mexico. This will keep me riding . bike mechanics here like to take jobs and keep your bike for days.

love these DIY tools. Thanks RJ

wonderful tool

instead of a ruler I use a set square on my home made device it saves you having to read the measurements, always enjoy your videos RJ so keep them coming

Thanks for the tips!! What a great little way to save some cash and be more self sufficient!

Thank you for this. I needed one a few days ago for my friends bike but I just took off the hanger and put it in a vise and hit it straight with a rubber mallet. I got lucky because now his bike shifts very smoothly and all I did was eyeball the straightness

thanks RJ, nice and simple, please make more tools

Very very clever my man. Thank you.

very nice, kind of useful tool.i will mke my own like this. thanks for this!

You are the man RJ. I'm making one today. Cheers man.

Great love it might have a go at that myself

Very helpful. Thanks for the easy step by step.

Well made bit of kit enjoyed seeing you make it, great video thank you

2021 I used the other method it worked ok but needs more tuning but the shifting id ok for now, Thanks.

DERAILLEUR HANGER ALIGNMENT GAUGE TOOL NICE THANKS I HAVE A CAMPY TOOL CABINET BUT I WAS ENTERTAINED

Fab fab fab...no nonsense just great stuff, making one tomorrow....

Thank you. Very helpful, love your work.

Ohh wow that's very useful tip & hack. Thanks RJ

I like your work Thanks for the tip

Very good as usual, thanks for sharing. I think with little more time you can improve the other end of the tool.

Thanks "Master"... Always learning from your vídeos.

That's what I need. I have been thinking about making one of these.

RJ. I made the tool...tool worked great. Thanks

Genius! I'll be making this for my upcoming road bike teardown and rebuild this winter. One thing I might do differently is add nylon washers between the metal washers and the steel tube on each side. That should make it be able to turn a little easier.

Thanks Man, you just saved me 60-80$. Love your channel!

That is fantastic. Thank you.

Great work, easy and professional

Great video! I am making one of these...!

another great idea. I will be making on of these. you have some great videos. Thanks.

Made one today - excellent, as usual.

You a genius RJ !

Excellent video. I can't wait to make my own alignment tool.

So I've made one of these using cabinet rail stock, works about the same as the old Park DAG 2 (supposedly the 2.2 has less play and a better head for thru axles). I found that adding wavy washers took out some of the play in the system but not all. I might try to get a friend to weld a plate on the rail to make it stiffer.

Just great RJ! The ridiculous asking price this simple tool from parktools(& others)was keeping me off the bike,and very frustrated.... U R a godsend !!

Thanks for the tutorial RJ. I'm going to spec out a bolt with a shank... it probably doesn't gain you much in accuracy, but the contact of bolt threads - to - drilled hole will open up the hole sooner (in theory anyways).