I am only 5mins in and already this right here is the best derailleur replacement and tuning guide on youtube . I love the angle of the fly wheels under the cassette and dialing in high and low screws . Incredible !! thank you !!!

I never thought to pre-index the rear derailleur before fitting the chain but it worked like a dream without any barrel adjuster adjustment afterwards. Crisp changes and no rattles whatsoever. And this is a 20+ year old SRAM derailleur! It took maybe 20 minutes. Brilliant. Thanks

Best tutorial I've seen on this. Installing a GX groupset today. Thanks a ton.

Wow this was better the the park tool guys.

This is without a doubt, the best video on this subject.

Thanks mate - I can always count on your videos to be complete and very 'real-life' practical!

Perfect! This is all the info i needed, thanks! WAY more articulate and detailed than other, more highly viewed, videos that glossed over critical information.

So brilliant getting the info across to the ordinary people in biking, thank you 😊

I got the GX derailleur and just waiting for the GX shifter and chain to come in the mail. When I get it I'll be sure to watch this guide again during the install. Thank you!

Well done sir. I finally understand what is going on back there. Thanks!!!

BRILLIANT VIDEO! The best one I've watched on the matter and after close to 50 I finally got to see exactly what you were doing.

Thank you! Fitted a new derailleur to my bike this evening following your instructions inc. indexing the gears with the chain off... Works a treat!

Excellent instructional video! I looked at several and yours was the only one I consider complete with cautionary notes on areas that cause problems. Thanks very much!

Great this. Thanks for taking the time.

Just followed your video, thank you so much!!

Thanks! Helped me out a ton

Hi just to say a great guide at the right speed of info as well. Good to hear a West country accent (ex Bristol now in New Zealand) cheers

Found this video really useful, replaced rear mech with ease today following this.. Many thanks

Really helpful and well explained Especially the bit about the rotation of the cam around the B screw.That's easy to miss if you don't know about it.Big thanks.

Great ! Makes this adjustment so much easier !

Best video I have seen on this install yet. Kudos and great work.

Great video helped me fit my derailleur nicely even though after taking note of your comment about not pulling the cable too tight when doing it up I still managed to make just that mistake all sorted now thanks for the help

You turned what would of been a headache into a quick and easy job. Thanks!

Your videos are spot on mate. So helpful, detailed and dont talk on about anything but whats needed. Thank you, made reinstalling my sram nx easy.

Quality video, thanks. Been trying to understand stand this fully and now I do. Cheers

Thanks! Worked perfect following your guide steps installing a new GX derailleur!

best video on this by a very long way - very clear visuals and the easiest way to do it, thank you very much, well worth a donation which I will be making.

Such a thorough guide you have shown. Cheers.

Thanks man! As always, great instructions, and my new GX Eagle Lunar (520%) shifts smooth as butter :)

My GX derailer is here, im just waiting for my Powerlink, upgrading the SX derailer on my Marlin 8... I've watch this video from start to finish about 5 times and I have almost memorised your steps! Thank you. Can't wait to do it, the Local bike store wanted to charge me $80 bucks to do it. Now i save some money and learn how to do things myself :)

You're amazing!! Thank you for such a thoughtful and thorough vid. Exactly what I and people like me need!

Thanks a lot for making this video. The instructions are great and really helpful!

Brilliantly in depth video. Thanks for this as I found it very helpful.

Perfect. Well explained. Cheers from Finland

Brilliant video. Very clear and made it easy for me to change my mech.

I must say this is super informative! Thank you sir.

thank you for this clear guide.

Good video. Before nipping up the cable on the derailleur, you should mention to turn the barrel adjuster out a bit for fine cable tensioning.

Thank you so much for this tutorial not even sram is this good.

thx, just got a gx rear mech, gone from 11 to 12, and did not realise the cable needs threading through the guide after the pulley at 7:50 so thanks. my cable kept jumping off the guide and could not work out why.

Thank you for this

You explained it really well, thank you

Exactly what I was looking for, thank you.

Just replaced my GX rear mech how easy was that thanks dude 🙌🙌

thanks man! Good work!

Thanks, just fitting it now.

Love your video made the how to do this actually do able with far less adjustment later needed. Thanks!

Great video. Thanks 👍😊

Thank you very much for going into this level of detail, this is incredibly helpful. While I will probably let my local bike shop install a new SRAM derailleur on my daily driver just to get it up & running as quickly as possible, I will most likely eventually build a bike from scratch with a SRAM NX drivetrain, and I will be revisiting this video often.

Very good vid sir!!!! 😎

Nice and clean guide 💪🏽

Very helpful thank you

Thank you, brilliant instructions ❤

my god i cant thank you enough for this vid life save man

Great video man, thank you

Really great video sir. Thanks so much!

great video...thank you.

best in depth video

Thanks for you sir

Well, just realized GX 12 speed model doesn't use a bolt, it is riveted instead, but the hole looks like a 2,5 allen bolt 😅. I just drilled it and replaced it with a Leonardy Factory kit that includes pulley and bolt, as there are no Sram spare parts for this model. Thanks for saving me a lot of money!!!

Very helpful. Much better than the one from sram. Thank you

good video, thank you

thank you👍🏼

Thank you!

This is what I have on my bike. Works fine.

Thanks a lot

Hi, great video and well explained. Pls can you also suggest what type of pulley's (jockey wheels) one should get to fit the Sram GX derailleur if you were to replace them?

Thanks for the video! I'm facing a lot of issues wit GX rear derailleur. Shifting became hard after some time. I can see the cable pulley on the derailleur doesn't move smooth. I can see there is an spare part avaiable for X01, XX1, but not for GX. Do you know if the cable pulley can be removed? I tried to unscrew the bolt but it was impossible

Thanks for the video! Is there a DIY way to avoid using the red B-gap tool? thanks!

Great video. But did not work at me. When I fixed the wire, I couldn’t shift in to the first/bigest gear. I needed to push derailleur to the bigest gear and then tight the wire. And also need to adjust the wire on the shifter. Your video helps really a lot to understand how to set the derailleur.

Good video I thought you were supposed to do b tension in second largest cog at sag.

Great video! Really helpful, love all your stuff. I could probalby build a space ship with the instructional videos that exist on you tube. 🙂

Very thorough, Thank you, very much! There is also a white plastic tool that come with the kit, sort of like the red one you used to true the gap between chain and cassette. Do you know what the white one is for and how do you use it?

Locking feature is really cool.

I've just removed my derailleur to check the hanger alignment. Before removing it, I noticed that the B screw was pushing against the hanger, and NOT the little tab on the derailleur. The screw has actually caused marring of the hanger, and my hanger is actually just an extension of the frame - it's not separate. (steel frame). Am I to understand that the tab should be INBETWEEN the hanger, and the end of the B screw, such that the end of the screw rests on the tab? Is that the only purpose of the tab - to protect the hanger? Seems a bit odd.

Thanks so much!

Mate, so I'm trying to run a SRAM GX 2.1 10-speed rear mech with a SRAM-Red 10 speed road shift lever. I can't seem to sort out the shifting around the 3rd and 4th cog (starting from the lockring) area on the cassette. It either won't shift up - and when I adjust it shift up - then it won't shift down. Any tips ? Cheers !

Did you have to remove shock or deflate sag for chain fitting and b screw adjustment?

Subbed and paid you a tenner (USD). On adjusting the B screw do you still need to do so with the frame in sag position? I didn’t see you make mention of this but wanted to check. Cheers.

My cage rams into the cogs when I release the cage lock. What did I do wrong?

Was wondering how come you did not show how you determine the length of the chain. I am assuming you had to cut the chain to size. Or no?

Whete u get chain protection

I put a gx derailleur onto a sx cassette and I have grinding noise when I backpedal and my chain came off once.. my bike shop told me I need a gx cassette to solve the grinding