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I've been reading up on Sram's CX1 1x11 cyclocross-specific group. It hinges on two technologies to minimize the potential for dropped-chains/chainslap. The CX1 clutch rear-derailleur keeps the chain in tension, while the wide-narrow single chainring resists lateral movement.

I am curious if there's any possibility to leverage the benefit of the clutch rear derailleur for chain stability, but still use a standard double-ring crankset?

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This does not work in the specific case of a Sram CX1 rear derailleur, or the case of any other X-Horizon™ mechanisms.

I purchased the CX1 derailleur and attempted with a 46/39 front chainring combo. The CX1 RD allows the front shift to occur, but has no tolerance for changes in chain length (e.g. front shifting).

The change in chainring size impacts the upper-pulley distance from the cassette cogs. Adjusting the B-limit for one chainring size results in a bad configuration with another chainring size.

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Yep, I've been using such setup for an year now, on my MTB (2x10).

See the "Technologies" tab on SRAM's page for X9 RD Type 2.

The equivalent technology by Shimano is called Shadow+ (note the +). When purchasing an RD, on can notice, that the price difference between having or not having the relevant technology is relatively small compared to the price of the RD.


On the other hand, I believe that the unique technology in SRAM's 1x11 grouppie is the shape of the chainring teeth. It is claimed to make the use of a chain guide unnecessary.

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    More manufacturers than SRAM make "narrow-wide" chainrings. With a clutch mech they are like black magic for keeping chains on. I rode a week in the alps this summer and with a Zee mech and Works Components chainring, didn't drop the chain once. – atlaz Sep 3 '14 at 13:14
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You wanted to mod a system that depends in part on the use of wide-narrow chains and chainrings.

Wide-narrow chain and chainrings are not compatible with front derailleurs. Assuming you have wide-narrow chainrings, when you front shift the narrow-wide chain may not find the right width tooth on the chainring and will either slip or derail. At best it works slightly crappily, at worst it’ll skip and derail like crazy. So you’d need to change both your chainrings and chains out for a regular fixed widths.

However, I assume you replaced your chainrings and chain to standard width when you added the front derailleur so this is relatively moot.

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