clutch RDs ?

[AngryScientist]

How do these work?

what "releases" cable tension to go down the cogset?

i'm putting a plan together...

[batman1425]

Originally Posted by AngryScientist

How do these work?

what "releases" cable tension to go down the cogset?

i'm putting a plan together...

Two separate mechanisms for chain alignment vs. chain tension. The "clutch" is an extra strong spring in the cage that pulls the chain downward with more force than a standard cage would. This is distinct from the spring in the parallelogram that is responsible for the tension that facilitates gear selection. Clutch tension should be constant regardless of gear selection.

[mistermo]

I always see clutch derailleurs paired with 1x cranksets. Will they work with 2x as well?

[batman1425]

Originally Posted by mistermo

I always see clutch derailleurs paired with 1x cranksets. Will they work with 2x as well?

Yes. Common in the mountain bike world where chain slap/popping off the rings from bounces is more of a problem.

The adoption for 1x is largely due to the used of narrow-wide chainrings with out an extra chain retention device at the chainring. The Clutch keeps the tension firm which in conjunction with a narrow wide ring is typically sufficient to keep the chain on the ring.

[AngryScientist]

ok, this all sounds positive. thanks batman.

who hasnt wanted to say that at some point by the way.

thanks batman.

[Mark McM]

Originally Posted by batman1425

Two separate mechanisms for chain alignment vs. chain tension. The "clutch" is an extra strong spring in the cage that pulls the chain downward with more force than a standard cage would. This is distinct from the spring in the parallelogram that is responsible for the tension that facilitates gear selection. Clutch tension should be constant regardless of gear selection.

The clutch isn't "an extra strong spring". It is a one-way friction device. The cage retracts easily, but it takes more force (due to clutch friction) to extend it.

(This is kind of like Suntour's "Power Ratchet" shifters, but as I understand it, the derailleurs use a roller clutch rather than a toothed ratchet.)

[batman1425]

Originally Posted by Mark McM

The clutch isn't "an extra strong spring". It is a one-way friction device. The cage retracts easily, but it takes more force (due to clutch friction) to extend it.

(This is kind of like Suntour's "Power Ratchet" shifters, but as I understand it, the derailleurs use a roller clutch rather than a toothed ratchet.)

Thanks for the clarification. Follow up question for my edification - if it is just friction that inhibits movement, why have a lock out for installing/removing wheels? Seems that there is an aspect of tension involved for a lockout to be valuable.

Edit - more googling, a lockout is for reducing chain tension effectively turning the system off to facilitate wheel changes... Shimano use a band clamp with a friction contact surface to reduce movement - pulling the OFF switch drops a cam that lets the cage move freely again, Sram and the roller bearing clutch - a mech to disengage the locking bearing - same effect, free movement.

[Mark McM]

Originally Posted by batman1425

Thanks for the clarification. Follow up question for my edification - if it is just friction that inhibits movement, why have a lock out for installing/removing wheels? Seems that there is an aspect of tension involved for a lockout to be valuable.

The lockout (friction disable) makes the derailleur cage act like a 'normal' derailleur, making it easier to swap wheels and do derailleur fine-tuning adjustments.

From the Bike Rader review of the Shimano XTR Shadow Plus derailleur:

The technology behind the concept

Inside the Shadow Plus derailleur is a spring-loaded one-way ratchet gear surrounded by a band-clamp. When the Shadow Plus switch is in the off position, the derailleur reacts like any other with a spring loaded lower pulley cage. With the switch in the ‘on’ position, however, the clamp tightens, engaging the ratchet.

The gear wants to ‘ratchet’ backwards freely, but it must pull against the band-clamp, which acts as a sort of clutch to prevent the pulley cage from moving forward; it can move forward but it takes a considerable amount of force. The end result is an almost fixed lower pulley cage, which prevents the chain from slapping the chainstay or bouncing off the front chainring.

The derailleur is meant to be ridden with the switch in the ‘on’ position all the time, but the ‘off’ setting allows shifting to be initially adjusted or fine-tuned and also makes it easier to remove the rear wheel.

[batman1425]

Originally Posted by AngryScientist

i'm putting a plan together...

So what's your plan?

[commonguy001]

I've used them on both 1x and 2x drivetrains (2x was on a MTB) and love that you get no chain-slap going over rough stuff, just silent and the chain never drops. Apparently Sram has introduced V3 of their 1x clutch and I'm pretty keen to try one seeing as I have a Rival1 now that's a bit tweaked.

Overall - positive experiences running clutch derailleurs

[sandyrs]

Originally Posted by Mark McM

The lockout (friction disable) makes the derailleur cage act like a 'normal' derailleur, making it easier to swap wheels and do derailleur fine-tuning adjustments.

From the Bike Rader review of the Shimano XTR Shadow Plus derailleur:

Just to note, SRAM does not feature the ability to disable the clutch; they only have a "lockout" that secures the cage well fore of the cassette and allows you to install/remove the wheel with no tension in the chain.

[Ed-B]

Clutch is the way to go for gravel! And not just 1x drivetrains, either.

Sram GX mtb clutch derailleurs are great on gravel/cyclocross bikes with two ring cranksets. There is no chain slap over the bumpy stuff, and the long cage variant enables the fitment of big cassettes for wide ratio drivetrains.

I'm running a Sram GX long cage clutch derailleur with a 12-36 10 speed cassette on my 650B London Road, and I shift it with Campy 10 speed ergos! Works great!!

The GX derailleurs are Exact-Actuation, so they'll work with 10 and 11 speed drivetrains. These derailleurs lack a cable tension adjuster - you need to have inline or cable stop adjusters.

Shimano does not presently offer a mechanical clutch derailleur that is compatible with their road groups, you have to use a cable pull equalizer like the Wolftooth Tanpan. The Di2 mtb clutch derailleur works with road di2, however.

BTW, I just came back from riding a 650B converted Raleigh Willard 2 with an Apex 1x clutch derailleur drivetrain.

Ed.

[Tony]

Shifting takes more force on the shift lever to move the clutch derailleur. With my Shimano clutch RDs shifting is smoother, faster without the clutch engaged. I run the clutch engaged 50% of the time depending on the trail on all my 1X mtb setups, very rarely do I ever drop a chain, and never when the clutch is engaged.

[chiasticon]

Originally Posted by mistermo

Will they work with 2x as well?

not all of them will. for Sram, the Force1/Rival1 stuff won't (or isn't designed to), but some of the mountain stuff will. it's type 2 versus type 2.1 I believe...?

[batman1425]

Originally Posted by chiasticon

not all of them will. for Sram, the Force1/Rival1 stuff won't (or isn't designed to), but some of the mountain stuff will. it's type 2 versus type 2.1 I believe...?

Correct - any X-horizon equipped sram rear mech won't tolerate 2x well. I think exact actuation non-x-horizon MTB der should work though...