Destroyed Derailleur/Bent Twisted Hanger - I Can Fix This!

I found a free Trek dumpster bike with a broken mangled derailleur. It was ripped in half! And the derailleur hanger was twisted around almost 45 degrees. The bike was trashed, but hey, it was free! I am guessing the derailleur hit something, and the cage was torn from the body. Maybe the cage got caught in the spokes, though no spokes seemed damaged. I am just guessing. Anyway, I managed to straighten the hanger, and replaced the derailleur with a similar model. I also replaced the rusty chain. The bike will come back to life. The bike is a Trek 820.
This is the derailleur hanger alignment tool I used (Park Tool DAG 2.2):
www.amazon.com...
How To Make A Derailleur Hanger Alignment Gauge Tool:
• How To Make A Deraille...
How To Make DIY Dropout Alignment Gauge Tools:
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[@RJTheBikeGuy]

For more bike repair videos hit the subscribe button 🛑 and click the notification bell ► bit.ly/SubRJTheBikeGuy

[@bellavia5]

Just watched this again. What a score. "One man gathers what another man spills". -The Grateful Dead

[@BulletmanDoom]

Have you seen the price of Park Tolls in the UK? 😲😲😲😲!!!!!!!!

[@armandolauder6598]

don't have high tech tools like you but .. i restored alot of BMX's and 10 /18 speed bikes with other parts i find and hope parts fit other parts.. and of course .. then some idiot steels it ..why ???

[@petert3535]

@@armandolauder6598 I feel your loss bud... You should definitely check out some more of RJs videos though, he's got a lot of videos on how to help yourself out when you don't have the proper tools on your hand!

[@navi-charlotte]

ouch... so that is why replaceable hangers were invented... well, I just wish there weren't like 10 thousand types of them.

[@buckhorncortez]

The fix isn't "dangerous." It's steel and won't fatigue from straightening it out one time. Steel degrades gracefully. Before it broke, you'd see the place that was straightened work-harden first (a line would form), then it would crystalize, and finally a crack would form. It WILL NOT suddenly break off.

[@buckhorncortez]

What "damage" does it receive from the road? The hanger is at least 3/16 or 9mm in thickness. It is a low stress point on the bike as the forces (weight of the derailleur) and tension applied by the chain to that point are very small in comparison to the thickness. The modulus of elasticity of steel in 3x that of aluminum - about 30 x 10^6 ksi. Look up "Young's Modulus of Elasticity for Metals and Alloys," or reference ASME B31.1-1995. Yeah, having owned a machine shop and worked with steel, aluminum, titanium and other metals - I'm sure the repair is just fine.

[@buckhorncortez]

No, it's not "just for fun," it's called attempting to protect yourself from product liability law suits. Body-on-frame automobiles are popular with police departments specifically because the maintenance shop can straighten the steel frame - as cop cars get a lot of non-standard usage and frames get bent regularly. The frames are straightened multiple times before the car is declared unfit for service. I will guarantee that the police car frames are put under a whole lot more stress than a bike derailleur hanger.

[@RJTheBikeGuy]

@Camiboy 1p There are a ton of different flavors of replaceable hangers. Your best bet is to use google images and start looking for matching hangers. Or google the brand/model of you bike and see if you can find what hanger your bike takes.

[@dallasdandigitalproduction393]

@Yard Sale Dale Thanks for this link . Really helps me rn. Cheers

[@eruetifoster5162]

Good on you fixing this bike instead of allowing it to be thrown out. Far to often we're just disposing of items due to some minor damage.

[@rakso_ddl8677]

Erueti Foster 'minor' its not minor if you can't afford the tools to fix things like this

[@eruetifoster5162]

It's not not so much a case of being unable to afford repairing but is it worth repairing? Due to mass produced goods they're so cheap it's more expensive to repair than buy another. Maybe that's a challenge we can put to RJ The bike Guy? Can he come up with ways to repair bikes without average cyclists having to purchase specialized tools he used in this video.

[@rakso_ddl8677]

Yeh, I want to see him use some really cheap tools if any proper tools whatsoever

[@RJTheBikeGuy]

I have videos on making many tools too replace more expensive ones. Often cheaper tools can be used. Like in a recent video, I used a DeWalt Compound Miter Saw. I could have used a handheld hacksaw. It just would have been a PITA, taken longer, and given not as nice of results. But it could be done. I am showing you how to do things. If you don't have a tool, think it out. What else can you use?

[@kxlucifer]

RJ The Bike Guy my state got alot of people sell them minor damage bike to the scrap yard..me personally i invest money on buying vintahe bikes from ebay and restore them for either pedals and making it a motor assist bike.

[@dominikk.3706]

More video with this bike! ;)

[@michaelfabian2401]

Definitely! Love this restore and rebuild! RJ has inspired me to thumb thru my local paper and CL looking for a project bike to rebuilt and play around with myself

[@ShirimeCid]

I rebuilt a pretty decent bike all from scrap parts following RJ's all tips. It was a bliss of a project and I'm really happy of the results. Good luck!

[@michaelfabian2401]

Nice! I've always loved riding my bike and just pissing around with them. But now I've gotten this urge to really get my hands dirty and rebuild a fork, change out some cranks and drivetrains and completely restore some lower end CL bike or something I find through the local paper. Just to learn some things about bikes and be able to provide my own service and maintenance, instead of taking it to my LBS. This will be my summer project for 2017 lol

[@johnhampson7]

While it's true that the "Park Tools" aren't cheap, the bike itself was. The tools however can be used again and again, and if you can continue to pick up cheap or even free bikes like this one, then the process is extremely cost effective. Nice one RJ keep em comin'.

[@bogdanchitu6292]

Well, cheap tools tend to wear/break a lot faster :)

[@chester371]

Bogdan Chiţu they can also damage new parts

[@nealdew71]

John Hampson No I cannot agree buying Park tools defeats the purpose unless you are a bicycle mechanic.

[@BikeItUK]

Great work and another bike saved, big thumbs up! Good advice as always all the best Andy

[@bikeboy6674]

Your videos are like therapy! It's great how you can take rejected and discarded machines, and breath new life into them. Skills!

[@yosisoyshi]

Thanks for sharing your love of bikes RJ! The quality of your videos improve each time you upload (the editing, the flow and the speaking too) I now work as a bike mechanic and watching your videos with your attention to detail has helped me improve my skills. Great find! I also love bringing old forgotten, broken bikes to life :)

[@w.m.aslam-author]

We live in a throw away society. Good to see people like yourself value and recycle such bikes.

[@jensenhealey907efi]

Just curious, does anyone think RJ could still carry on a conversation if he had to keep his hands in his pockets? :)

[@RJTheBikeGuy]

Maybe I should do my video like this: kzbin.info/www/bejne/kHzbmXxqfpqep5o

[@jensenhealey907efi]

RJ, I am just funnin' wid ya. I like your videos and always watch the new ones.

[@jeffcuevas5918]

OMG, I now know saddness.... AND how to make chilli cheese crap! 🤣

[@joejose8433]

I just got came from another website one guy said he tied up to a tree in the wind bit the derailleur out of shape. Damn that's some f***** up a piece of s***... I brought a $200 Walmart bike Mongoose in the damn thing just bent and got caught in the f****** $200 going down the drain

[@txalvrs]

RJ: *Why do I fix everything I touch?*

[@kdshome3006]

My bicycle drailure has been stucked in the tyre and its shape has been changed . Can i repair it at home ?😕

[@schlooonginator1227]

Great video. I do most of my own work on my bikes but you are on another level as far as repairs go. I wish I had all the tools you have.

[@lekhapratap1652]

Saving an old discarded boy is always a cool thing. Letting it live. There’s something very cool and satisfying about bringing discarded and old things back to their former glory. I love it!

[@selrod55]

nice job! sad thing is the kid most likely was told by a shop the bike was beyond repair.

[@tasosliratzis893]

0:31 i don't know why but everytime i see this part i laugh

[@madeiraislander]

i was just pooooffh like that!

[@vivitar45]

I hate trying to fix this problem I had some times bad luck the threads be striped and in the end end up scrapping the frame

[@usstotts]

Nice to see a bike saved. Just out of interest what do you do with the finished bike - do you have much luck selling them.

[@RJTheBikeGuy]

www.rjthebikeguy.com/faq/

[@stalszenator]

it will live again!!! I love that! People throw so much stuff away. I learned a lot from your videos and nowadays fix my bikes and my girlfriends bike myself. Thank you and keep up the good work! Just one question: is it possible to just ignore the bent deraillereur hanger and mount a derailleur on there with an adapter so it fits on the axel? Or will the bent piece of metal be in the way?

[@RJTheBikeGuy]

Just use the existing hanger if you can.

[@thebestaligirisken63]

RJ , I have a bike without rear derailleur hanger and I can only use Shimano Ty300 bracket. I want to adjust Acera but I can't . Can you help me please?

[@nameless4284]

must say that destroyed derailleur made for one of the most epic thumbnails I have ever seen! so awesome to see you breathing life back into that beautiful bike!

[@caroltaylor522]

Hi my friend was jus wondering where u purchased the new/replacement hanger that u show illustrated in this video as I’ve been looking for that same one exactly and cannot find it anywhere??? Regards cris

[@RJTheBikeGuy]

I don't remember where I got it. I may have pulled it from a damaged bike. Be aware that there are LOTS of different replaceable hangers. And many look similar. You need to find an exact match for your bike. Start googling images of derailleur hangers, and find one that matches yours. You can also do research on your brand/model of bike to see what type of hanger it takes. www.google.com/search?q=derailleur+hanger&source=lnms&tbm=isch&sa=X

[@SmileyBoy84]

Its the first time I have seen your face 😊

[@RJTheBikeGuy]

kzbin.info/www/bejne/qGrNnqipnLKaqNE

[@SmileyBoy84]

😂😂😂😂

[@ascoria980]

lmao

[@TheMetalMachinist]

I love your videos RJ. I'd like to see you upgrade cheap Wal-Mart bikes with pro parts lol

[@michaelmay9728]

Great work RJ, glad you Were able to save it, and it was the best price

[@MtDandy]

Destroyed Derailleur/Bent Twisted Hanger ...this often happens changing from 1 gear into another or maybe 2 gears too quickly while pedaling forward.

[@danmidkiff5416]

Great video! Keep them coming!

[@johnpossum556]

Nice save! I rescued a Ross so old I think it is one of the first mountain bikes ever. Nothing wrong with it at all, just age-rotted rubber. Put some wide cruiser handlebars on it, new seat, cargo carrier and milk crate and it makes for a decent grocery getter. Also high visibility puncture resistant street slicks for added safety while doing those late night grocery runs -- I never skimp on the rubber! (I'm almost wondering if it'd be worth more to some one if left original?) I'm constantly amazed at the stuff inner city folk throw away. Microwaves that work. I even got a digital soldering iron because the tip was bad. Brand new with the box. Studio quality microphone, too.

[@guillermosempron5776]

Best bike than mine :)

[@MoPoppins]

What a satisfying "rescue." I learn so much from you, RJ. You make bike repairs fun by demystifying it all and making everything an exciting ADVENTURE.! :)

[@koppekake5995]

Lol I've never fixed a bike before and yesterday I started a little project with the back gear and I'm finished soon

[@sabalisabali4952]

This happened to me today. Luckily, I was able to bend it into shape with a few pieces of wood and made it home. I know I can fix it now. Thank you for this video.

[@youtubecommentguy8871]

Glad the hanger didn't just crack and break

[@roberthsu94]

RJ the bike guy is batman He has every tool to fix the bike lol

[@popote1286]

Hi, Pascal from France at Le Mans, it's alive again, good work and also good tools. So, thanks for your video. I have a question, what to do when an aluminium part is " un-straigh" ?

[@RJTheBikeGuy]

If an aluminum part is bent, replace it.

[@lacticbumbleb207]

I have this exact problem on a Marin bike is it worth me giving this a go

[@JohnHughes2002]

You're like an animal rescue charity for injured or unloved bikes!

[@joe-vu7ce]

I just did that to a derailleur! Brought it to a bike shop Derailleur hangar threads might be unusable also!

[@joen3992]

The Trek 820 is their basic model....but it can take a shit kicking for a bike. I know people who own them for years. Commute in winter and ride on trails. Doesn't matter its steel frame. Still workable and its a nice color btw

[@Patrick94GSR]

That would make a great commuter bike with some smooth-tread road oriented tires on them, like Big Apples.

[@trekkeruss]

With a completely rusty chain, I don't bother with a chain tool. It's faster to cut it with bolt cutters, plus I don't have to worry about bending or breaking the chain tool's pin.

[@RJTheBikeGuy]

The chains get recycled for other things.

[@dkwoodworking8415]

Great job I to pick up free bikes and refurbish them. And if I have no money in to them I give them to kids that need a bike or sell them for just the price if the parts. Seeing how to use the park tools is really handy. I don't know where you got you knowledge of them but keep up the great videos thanks

[@Patstar777]

Nice save!!!

[@phieryone]

You are a master of your craft RJ. Keep the videos coming. You helped me restore my own bike, your knowledge is invaluable sir. Thank you.

[@SonukGupta-vk6uu]

can you tell me plzz which bike should i buy... or does the disc break work actually....

[@SonukGupta-vk6uu]

bike options disc break or v break

[@nightmareinaction629]

Sonu Gupta disc brakes are way better if you buy good quality ones

[@bellavia5]

Well done RJ !!!

[@yukiakira8922]

Good job. It is a really nice bike...has potential. :)

[@LurkingCrassZero]

A Trek for FREE!? :-o

[@jimmytorpedo6690]

Great video as always RJ. Consider doing some on spiritual guidance. I envy your patience and positive attitude along with your technical skills.

[@robofatcat]

Great work as always

[@richardfabrizio8998]

Nice job RJ. I like that model Trek too. Should work out fine

[@jayybizz_]

my whole system broke yesterday. The derailer snapped and bro just like in this video. At the same time my rear wheels got locked up and tangled. I almost died 😅

[@OWK000]

I just scored a freebie late 90's, early oughts, Marin East Peak fsr full suspension bike with a bent derailluer hanger and a REALLY rusty chain. (If the chain is really rusted, the quickest way to remove is two vise grip pliers on the chain near each other and twist opposite directions). The derailluer wasn't as destroyed, but there was more rust. The Sunlite cassette was chrome coated and the rust cleaned off it nicely. There are rusty bolts all over. Unfortunately this is an aluminum bike shortly before removeable derailluer hangers, but it looks like they folded some steel into the aluminum hanger and were thinking about making it removable and I just straightened it with vise grips . . . The derailluer looks still useable. I hope. It's a nice bike. I am really stoked. Nothing like a bike resuce. May be going ebike eventually, but the wheels are in really good condition and I think I will just ride it as is for a while.

[@roythearcher]

Not a bad job! Steel can also suffer from "metal fatigue" if its bent too many times but not as bad as aliminium. It's a good idea if you can, to heat the hanger up to red heat with a torch and let it cool down naturally to Stress relieve it after but this should only be done on welded frames, (not brazed!) and if you're planning to re-paint after. A good save of a nice bike!

[@GODFATHERLO]

[[[[[[[ Great find ... That bike costs as much as a nice used car when new, and probably as much as a decent used car now after repair. Looks like she's gonna bring you a profit!!! ]]]]]]]

[@burntkat]

That bike cost about $300 new. $350 at the outside. Still a nice one, though!

[@blakebeyett6471]

Does anyone know the newer derailleur he used?

[@Desi365]

i think it's a vintage Acera X 8 speed RD. My guess.

[@rjrux5190]

my name is RJ!!!😱😱😱

[@TF856]

I bet you could have fixed that chain and that derailleur. I had a five speed bike when I was much younger and that derailleur was all the time getting mutilated and bent all up and I was always able to straighten it out and repair it. I was often surprised and amazed that it never broke off. It must have been really soft metal.

[@cschuh4695]

Nice bike, and definitely worth saving... Excellent video, as are all of your videos... Thanx, RJ...

[@jameswilson2815]

When you say I think I can fix it, I KNOW you can fix it! Your skill and knowledge of bicycles inspiring! Gotta go fix my fork now. Keep it going brother. Aloha

[@gvi341984]

How about cleaning the bearings? Truing the wheels?

[@RJTheBikeGuy]

I have videos on those things.

[@gvi341984]

More videos about this bike though since it has a very interesting story to it

[@Chrisisbiking]

you are such a bike wizard love what you do inspires me to do something like this keep it up you're amazing!!

[@DannyBoy-vg6kp]

Awesome, I hope you do more videos on this bike.

[@AntonMoquin-vg1sy]

Felt on your thumbnail. RIP And respec on your clean hands while doing chain work

[@ZER0value]

RJ loves a good Trek!

[@raymondchew8894]

Many repairable bicycles were thrown away and eventually become scraps. Especially during the pandemic, costs related to bicycles and parts are getting more expensive. How can we sustain these in long term ? You have fulfilled a mission by saving these bicycle from the graveyards. Thus help promote sustainability and lower unnecessary inflation costs !

[@robkunkel8833]

Thanks. A clear guide to trying to repair my 8 speed derailer that derailed after a fall with my 3 day old bicycle. 76 years old and my first new bike with a derailer. It went down after a minor accident avoiding a car. Damn … but good to have this video.

[@damntuff62]

top job RJ good to see those alignment tools being put to good use

[@thewanderer673]

Can you please elaborate why did it happen! It just happened with my Shimano Sora derailleur. I couldn't figure out

[@НиколаМихалев1010]

This has happedned to me.I was on te streeet ridng and sudenly my derailleur snaped in half just like tath one and i think it was the same model.So its pretty easy for this kind of thing to happen.

[@bobby3704]

my hanger is off and needs to be adjust .. can you come over and bring you park tool with you . .. Please . I'm in the west coast Los Angeles area. i'll be in the garage come on in .

[@jontaylor4511]

i'm working on one where half the derailleur is missing, it's probably not worth me trying to make a rear plate and find wheels for it, will probably just put on another acera or cheap sunrace. that seems a later model of the trek 820, better specs than mine.

[@camfg8908]

Great job. You should fix all the rusty and broken bikes that are laying around here throughout year. It's sad to see them like that.

[@shmu_el]

a few yoear s ago I put something that looked like oil but it was not (probably DOT) and it worked great for a week and then the chain was pretty much in the same condition as this one and almost broke my jockey wheels. So I suppose something like this happened here because the bike's in a great condition but the chain looks like it's older than life...

[@markkouros6628]

Great job lives to rude another day survive the onslaught of time , my derailleur actually snapped where it bolts onto the bike , broke a spook too .. Good day , keep going..

[@cowboybuddhaful]

Great repair, having the same issue but no fancy alignment tool :(

[@_gajewski3626]

I have the same problem with badly bent frame integrated derailleur hanger in a cheap Bianchi bicycle I bought. This video gave me hope that it can be repaired.

[@mikeoniones667]

Ah I can fix anything throw money at it... I wanted to know how to fix it poor boy stile using broke stuff.

[@TheGeffry]

Give this man a cookie! Before I've found RJ's videos, I took my road bike to the mechanic with every small issue, now there are only a few things I can't do on my own, mainly because of the lack of tools.

[@jeepsblackpowderandlights4305]

This happened to my brand new bike.. i spent 300$ at walmart.. was a awsome looking bike. First sit on the seat i stepped on the pedals and the thing just bent like cheese... no idea why

[@trimmerman1]

I never find anything that good at dumpsters. Usually sad knockoffs instead.

[@dippster357]

Hey, RJ I'm hoping you can help me i have a mountain bike that i replaced the hand gear shifter on the right-hand side i have both Shimano gear shifter and derailleur i tried both the high & low screws and the derailleur barrow and nothing seems to move my derailleur to switch gears, whatever i do it remains in the smallest cog, i checked to see if it was the cable, but the cable tightens and loosens so it's not that, have you ever had this problem? i can't afford to take it to a bike shop and i worked on this for a month and still it won't shift! please reply!! i need help!

[@ryanschaefer1209]

This is useful just to see how to use a Derailleur Hanger Alignment Gauge. The bike project is pretty cool too.

[@bruce5799]

I wouldn't of dumped that bike,just a little know how and a few used working parts and the bike can be used again.

[@mariozermeno2649]

nice rescue!

[@jif8802]

Nice Find...

[@ciancullen3153]

Nice video!!

[@mikespringer7894]

sweet find

[@dirtybauer7022]

Once the initial molecules of the metal has been broken that metal is no longer structurally sound. I used to break metal in a fab shop.

[@tonyfrewin4822]

It’s great saving a dump bike. That will be a good bike for someone.

[@JesusChavez-gt4qt]

I learn something new everyday! The bike world is truly amazing!

[@jakecole7447]

So why is there a steel deraileur hanger ? isnt it always aluminium for reasons to save the derailer ? (Which wouldve been a smart move in this case lol.)

[@MsJessejackson]

Either get in the frame or get out of the frame. But to see you detached arms waving around like mad is really distracting.

[@Jackiemk007]

The same thing happened to my bike... can I just leave the derailer off?

[@joen3992]

Finally a video I can show friends that proves that if your RD hanger is out of aliment, then your RD will never shift right. Thanks RJ.....Also, the Trek 820 was the last bike they made until 2015 that was made of steel. Cheap, solid and if taken care of right, runs for years and years....

[@_exdenz_233]

My whole hanger snapped because it was aluminum, any way to fix this?

[@chuckwalla2967]

If my bike doesn't have a derailleur hanger, can I add one and still keep the same derailleur?

[@Saddletramp1200]

GREAT JOB! sure would be nice if I could find a TREK bike for free.

[@slifer0081]

My brand new 315 euro bike's gears just COMPLETELY twisted and broke off after I switched gears. Not even close to what you have shown. I do not understand how.

[@RJTheBikeGuy]

Ouch.

[@TonyVeart]

Good video which I enjoyed. Looking forward to see how this bike turns out.