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Issue with SRAM Red rear derailleur adjustment

19239 Views 25 Replies 15 Participants Last post by  protocol_droid
Just wanted to share my experience as of recent when putting together my bike with SRAM Red and the issues i had with the adjustment of the rear derailleur.
I was unable to get the red rear derailler to shift to 11t on the cogset, despite the adjuster being all the way out and not restricting the outwards movement.

Note: on the bike a Dura -Ace 7800 rear derailler functioned flawlessly.

Without going into too much details, it appears as if the Sram red derailleur does not have the range of motion as the DA 7800.
The issue was resolved by installing a washer between the derailleur and the Hanger.
Shifting is now flawless.
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Strange -- first I've read about it...Did you swap the cassette as well? Did you accidentally put two cassette spacers behind the cassette?

Asad
more info please...

I've built up at least a dozen bikes with Red and I have never experienced this issue.

Frame make, model, size?

Wheelset make, model?

cassette make, model, size?
Spectrum said:
Without going into too much details, it appears as if the Sram red derailleur does not have the range of motion as the DA 7800.
The issue was resolved by installing a washer between the derailleur and the Hanger.
Shifting is now flawless.
If it is now shifting flawlessly how can it not have the "range of motion" as any other derailleur? Either it covers the range and shifts or it doesn't. The washer would have 'fixed' some other problem with your bike/setup like a bent hanger.
The Hanger is perfectly straight, i had this checked at the bike shop.
Cassette has no spacers since the SRAM cassette does not require a spacer.
The wheel are Reynolds Assault.
We also tried a Mavic rear wheel with a Dura ace cassette and the result was similar.
From what i can see, since it's a Titanium frame, the hanger is noticeably thinner than the Aluminum hangers, so this may have contributed to the derailleur being in a more inward position. With the washer, everything is working flawlessly.
Okay, first let me apologize for the picture quality. I took these today with my phone, which actually has a 5mp camera, but it doesn't work so good for close shots.

The problem is that with the "H" limit screw turned as loose as it can go the inner parallelogram link of the RD contacts a silver screw on the knuckle that contains the spring for the pulley cage.

I just happened to come across this today working on a bike but I have indeed seen it before. This has been an issue with SRAM mtb RD's before and I've seen it a few times on their road RD's. Mainly the RED RD.

The profile of the head of the screw on the knuckle looks to be a bit too large. Maybe SRAM made a running change and used another screw from a different supplier, but I'm only guessing.

These were shots from a SRAM RED RD on a Cervelo R5 with a RED cassette and Fulcrum Racing 5 wheels. All components including frame are brand new out of the box.
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j.king, thanks for the tip. I'll will definitely look into this since i had the H limit screw all the way out. I would love to eliminate the washer :)
@j.king.
Unfortunately that screw is all is all the way in and it seem the contact is directly on the body. So i guess I'm stuck with using the washer, which as a matter of fact promotes better mobility on the derailleur. Thanks for you help.
The deraileur body is designed to be a certain distance from the lowest cog of the cassette. This can be impacted as you've noted by the thickness of the dropout / deraileur hanger. From what you've described the deraileur is too close to the cassette forcing it to operate at one extreme of it's range of motion. If you where to losen or remove (don't do this) the low adjustment screw I would imagine the deraileur would shift clean into the spokes causing all kinds of expensive damage to the deraileur, wheel, and possibly the frame.

The washer you've added seems to have done the trick to get the deraileur body in the correct starting position for your bike. If it works and there are enough threads in the hanger I wouldn't sweat it and just ride it and love the Sram shifting. :)
@j.king.
Unfortunately that screw is all is all the way in and it seem the contact is directly on the body. So i guess I'm stuck with using the washer, which as a matter of fact promotes better mobility on the derailleur. Thanks for you help.
Did you try to see if maybe you could use a different style screw, maybe one with a more dome shaped head? That screw is pretty flat at the top and I'm wondering if something more round would help.

Otherwise I'd head to a local shop and see if you can get it warrantied by SRAM. As far as I know there is nothing that says their RD's only work with certain bikes. Seems like a design flaw or a sourcing flaw as far as that screw is concerned.

Keep us posted on what happens.
j.king -- I think he's saying the screw is screwed all the way in and so isn't interfering, it's actually the two parts of the body of the derailleur.

Asad
j.king -- I think he's saying the screw is screwed all the way in and so isn't interfering, it's actually the two parts of the body of the derailleur.

Asad
Yes, you are correct. I misread his last post. Sorry.
Thanks guys. The washer did the trick. I will be posting a Pic soon.
Fixed!! Thanks J.King

So the issue was finally resolved without the use of the washer. I had to get to the bottom of this nagging little issue and i guess i refused to accept that the washer was the final solution.
I finally removed the derailleur, and although the screw was all the way in, the head of the screw was protruding and was coming into contact with the parallelogram. I backed out the screw a few turns and proceeded to grind the head with a flat file.
The result... i was able to get a few millimeters more outward movement which was exactly what was needed. Now i shift into the lower cog flawlessly without the use of the washer.
This is definitely a design flaw by SRAM.
Thank you everyone
Awesome! Glad you were able to fix it. I'd contact SRAM if you can. I wonder if they are aware of the issue. I've seen similar issues on some of their other derailleurs, mainly mountain bike derailleurs, I wonder if it's a design problem with their parallelogram. I know in this case it's that screw that gets in the way but I'm still curious how this went through quality control without being caught.

Once again, glad to hear you got it fixed.
Had this same issue with a 2012 SRAM Red rear derailleur on a Lynskey frame. The screw head in the pic in the previous post was not interfering and I could not get the chain to run smooth on the smallest cog. It would stay on the cog but keep jumping up and down against the next cog. I see no way to adjust the derailleur out any further. The titanium hanger is half the thickness of an aluminum one and appears to be the issue. I put a small fiber washer between the derailleur and hanger and it seems to shifting perfect now.
Had this same issue with a 2012 SRAM Red rear derailleur on a Lynskey frame. The screw head in the pic in the previous post was not interfering and I could not get the chain to run smooth on the smallest cog. It would stay on the cog but keep jumping up and down against the next cog. I see no way to adjust the derailleur out any further. The titanium hanger is half the thickness of an aluminum one and appears to be the issue. I put a small fiber washer between the derailleur and hanger and it seems to shifting perfect now.
Wow, I think this is the exact issue I was having on my new Ti frame. I have the high limit adjusted as far as it will go. Most of the skipping is gone but it's not perfect. How thick of a washer did you use? I think I'll have to try this, maybe it'll make the drivetrain perfect.
I'm sure this probably isn't the solution to any of your problems but I'll pass it on anyway. When I put my 11/28 back on my back up bike I had a problem with skipping on the 11t. Found out I installed the lock ring off my 12/25 cassette. Lock ring was too big and chain was riding on it and not fully engaging the teeth on the cog.
Is this the same problem that Lennard Zinn mentioned on Velonews yesterday?

Technical FAQ with Lennard Zinn: Cyclometer on
Q. Dear Lennard,

In your recent column on the SL3 frame, if it is indeed a Roubaix, there is a 0.5mm spacer that needs to be installed between the derailleur and its hanger. Otherwise, try as you will, it will not shift right. It ships with the Ultegra bike and we have used it with success.

—Brad

A. Dear Brad,

I asked Nic Sims, the global marketing manager for Specialized Bicycles, about this. He told me: “There was a kit that is available from the customer service department that would rectify shifting problems with Roubaixes. The shim was a small piece that was used for SRAM only, and it pushed the derailleur over so that it would shift down into the 11 better.”

But if I understand you correctly, apparently it came with both in SRAM and Shimano bikes in some cases.

Adding space between the derailleur and the hanger increases the spring tension and essentially makes a derailleur pull harder on the cable.

― Lennard
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