2x GX 10s
Yeah, except that donât play well with bikes that have the cable exiting the end of the chain-stay like the OPEN, or the Norco Search. Hence why Bradenâs nokon piece is a good idea, assuming you have an inline adjuster somewhere.
Also the 2x GX is just not a very good dangler. Itâs the best option, but on my other bike where I can easily run a jtek, the 2x12 Gx is an entirely different beast.
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2x12 or 2x11 ?
As I understand the upper pulley on 1x is offset to track the cassette more closely. As you change chainrings, your dangler cage pivots to release or take up chain slack. The pulley is just about right on top of that pivot on 2x so it doesnât change much when you shift up front.
1x dangler works for 1x best, 2x will do both.
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Both 1x and 2x derailleurs need to have some method of keeping the upper pulley close to the cogs as you shift around from small to big cogs.
On a 2x derailleur, the parallelogram is slanted, so as the pulley cage move inward toward larger size cogs, it moves diagonally downward as well to avoid running into the cogs as they get bigger and bigger. And if you shift to a smaller cog likewise the slanted geometry helps the upper pulley stay close to the smaller cog as the derailleur moves sideways.
On a 1x derailleur the parallelogram is not slanted, so the pulley cage moves directly sideways. But the upper pulley is offset from the cage pivot. So if you rotate the pulley cage, you can also raise or lower the upper pulley and prevent it from hitting the cogs. So as you shift to a bigger cog, the chain gets âtighterâ and rotates the pulley cage which keeps the pulley from hitting the larger cog. As you shift to a smaller cog there is more slack on the chain and the cage pivots backwards and raises the upper pulley closer to the small cog.
This would not work on a 2x setup because as you shift from big ring to small ring in the front you introduce chain slack, which rotates the rear dangler cage and would put the upper pulley right into the cog (because you didnât shift the rear to a smaller cog, just the front).
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2x11.
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Slant parallelogram danglers always have the same slant no matter if the cassette is a corncob or a wide range, so the pulley path has compromises.
1x danglers the pulley moves directly relative to cog size and in theory is consistent no matter the cassette.
One advantage of 2x types is chain stay length changing with rear suspension travel has less effect on upper pulley position.
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prob this post, but I see @jimmthefly just explained it perfectly as well.
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interesting point about chain growth on full-susp bikes. I wonder if the 1x-specific derailleurs shift like poop on high-pivot designs like this: https://www.forbiddenbike.com/products/druid-xt-complete
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Thanks for explaining and referencing that older post.
It still baffles me that its worth creating an entire new 1x dangler just for the marginal gain of having the upper pulley tracking slightly closer to the cogs when 2x parallelogram danglers will still technically work. Is this because, as we have been evolving from 9-10-11-12 speed, the the indexing precision required is becoming too great for a distant 2x dangler to prevent ghost shifts?
Do you think there are there any other benefits of 1x danglers such as the clutch being more effective without the 2x parallelogram or ability to have any super wide cassettes without changing the angle of a 2x parallelogram?
Also thinking more about 1x danglers, wondering if they suffer the same issue I am having with a 2x Shimano RD-RX800 dangler. Basically when I am placing the rear wheel back in the dropout the dangler parallelogram, shifted in smallest cog, wants to push the entire wheel toward the driveside but I want to have it centered so I can get the rotor in the disc caliper slot. Basically I have to fight the dangler which is moving toward the centerline slower than I need it to go to not end up with the rotor inboard of the disc caliper. Anyone have this issue with 2x clutch danglers when they are dropping in their rear wheel? I never remember having this issue so pronounced with my other bikes/danglers.
The thing that actually drives 1x parallelogram shape is that vertical forces from big hits and bumpy trails will translate into some horizontal motion with a slanted parallelogram. A horizontal parallelogram is perpendicular to the force, so it is unaffected by bouncy roads and trails. But then you have to figure out a way to track the upper pulley to the cassette, thus the big pulley offset.
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You replace an XT dangler with the RD-RX800, right? I wrestle with the XT unless I flip my bike upside down, then the wheel drops right in.
Given the above discussion, does his chainstay-mounted dangler have any benefit by not needing to pivot around the cassette to take up chain slack? Or is it purely historical reenactment?
Oooh good point I didnât think of that.
Maybe another point in favor of low-normal danglers?
and/or Janâs desmodromic Nivex, checkmate!
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I have had this issue with my 105 11sp danglers, too. The only way Iâve found that isnât a wrestling match is using the 6th cog. YMMV.
I only get this issue with sram non-clutch derailleurs. The clutched ones have that doofer that locks it out for this task. I had forgotten what a PITA sram was until I went back to the 2x force wifli. Iâve never had this problem with non-clutched Shimano derailleurs.
The 1x specific design that Sram rolled out was a huge improvement over the 2x clutch derailleurs when people started moving to 1x as the standard for trail bikes. The 11 speed Shimano stuff that tried to straddle the line is absolutely inferior (despite what Shimano purists will say) and their fence riding was the driving factory for Sram gobbling up so much OEM spec when the dropped 1x11 and all the way through eagle until Shimano finally gave in and essentially copied what Sram was doing (even dropping their own âshadowâ design along the way) with the 1x12 XT/XTR groups that have now actually trickled back down to 10 and 11s via Deore.
When youâre dealing with a cassette with large cog bigger than 42 the 1x specific derailleurs are as mandatory to get good performance as a front derailleur is to operate a double.
What is really interesting is the 2x11 Sram trail dangler that borrows some features of the 1x stuff and slants the parallelogram making the best shifting double derailleur (with a clutch) ever made.
Anyone riding Sram 2x11 mechanical on any thing dirtier than a crit bike with a conventional cable stop on the chainstay should absolutely grab a GX 2x11 dangler and a Jtek.
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i am SO CONFUSED
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