Sram red rear derailleur issues

Discuss light weight issues concerning road bikes & parts.
NiFTY
Posts: 1061
Joined: Sat May 26, 2012 11:26 pm

by NiFTY

Cheers frankie, thought so. This is the third one I have toasted now. 1st one destroyed a lightweight, 2nd I caught just in time - would have toasted a rear wheel next ride. This one is a red 22 style one and thought that issue was resolved, and it has always been a bit off from new - hence my post. Have bought another today. I think its the constant cage movement with my q rings that is the reason I kill them so quickly.
Evo 5.02kg SL3 6.77 Slice RS 8.89 viewtopic.php?f=10&t=110579" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;

by Weenie


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Gearjunkie
Posts: 756
Joined: Tue Feb 19, 2008 5:17 am
Location: NZ

by Gearjunkie

Yes the axle that connects the pulley cage to the rest of the derailleur wears out. It is alloy and wears on one side but can't be rotated (or at least not easily) to use the unworn side. It also can't be replace since it is permanently fixed to the outer cage. Once it becomes worn, the pulley cage no longer moves in parallel with the rest of the derailleur, causing shifting issues. I have a collection of 4 worn Red rear derailleurs.

However there are now some solutions on Fleabay that replace the whole cage assembly including the troublesome axle (not just the inner cage). I haven't tried one yet, they aren't too expensive (compared to a new derailleur) but the axle looks to be made of carbon, so not sure how well that would last.

Cheers
GJ

alcatraz
Posts: 727
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

Has anyone managed to fix this so called "worn axle" problem? Pictures?

I got that spring tension gap too on my first generation red derailleur. Shifting is ok but I notice the weakest point in adjusting it is getting the 2nd and 9th gear to index correctly.

Seems to me the derailleur, in it's current condition, is expecting a slightly wider cassette than there actually is. (Upper pulley is a bit off to the side of the cog).

So should that gap be completely gone?

Also how straight does your bottom pulley align compared to the upper one? Seems to me that the hanger is designed in a way to allow the lower pulley to angle the chain inward when the derailleur is carrying more chain slack. Reduce the slack by shifting big ring or lower gear and the lower pully seems more straight, but still offset the upper one slightly. On my previous bike it's not like this.

I have very little chain rub in the 9th sprocket which I though is a cool feature but I'm still wondering what is right. Don't see any sram red 10s first gen derailleurs on the streets to compare.

/a

boots2000
Posts: 1423
Joined: Mon Oct 15, 2007 9:28 pm

by boots2000

I found 10 speed SRAM Red to be the most finicky of all SRAM groups.
Mine never stayed in adjustment, external and internal routed bikes.
Also- With a Tarmac, the frame itself was an issue.
It needed a spacer washer between the rear derailleur and frame to help the rear shift properly.
The front der?- it does not sit properly on the front derailleur hanger.
Mine worked a million times better when I substituted a Dura-Ace 7800 front derailleur.

However, Shimano released 9000 and I changed and never looked back to SRAM for a road group.

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Gearjunkie
Posts: 756
Joined: Tue Feb 19, 2008 5:17 am
Location: NZ

by Gearjunkie

Alcatraz, there is some gap (even with a new derailleur) but it gets wider with wear and creates an angle as the spring is put under tension.

You can see it when you rotate the pulley cage (putting the spring under tension). The gap will remain constant on a new derailleur but enlarge and distort on a derailleur with a worn axle.

As for the front derailleur, don't bother with DA 7800. The new Sram Red Yaw FD is far superior to both the original Sram Red FD and DA 7800.

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