The original equipment, 10-speed, SRAM Rival rear derailleur on my Musashi is becoming increasingly harder to shift with the bike's X7 trigger shifter. Has 9,579 miles on it, so it's probably time to replace it. Really like the easy-shifting X7 derailler on my Baron, so I'm considering replacing the Rival derailleur with an X7. Found out today that SRAM offers a Type 2 X7 derailleur (http://www.sram.com/sram/mountain/products/sram-x7-type-2-10-speed-rear-deraille ur) that has a clutching mechanism to control chain slap. Since the long spans of chain on recumbents bounce around, was thinking this Type 2 derailleur might control bounce, and save a watt or two.
 
Anybody out there have any experience with SRAM's X series clutching derailleurs?

Quote from Action Lad on Nov 11^th, 2013, 11:30pm:

 
Installed my Baron's X7 derailleur on my Musashi, and still have shifting problems. The shifter cable is not binding in its housing, so there must be a problem with the shifter. I'm still going to order a Type 2 derailleur, along with a new shifter, just to try one out.  

Quote from MrOverdressed on Nov 13^th, 2013, 4:49am:

 
OK, I'll do that. Decided to step up a grade and ordered an X9 shifter and X9, Type 2, derailleur last night.  

Quote from catroad254 on Nov 13^th, 2013, 10:03am:

 
Yeah, a clutching derailleur might eliminate that occasional clunking in your Aero's driveline.
 
As opposed to Shimano's clutching derailleur, the clutch in the SRAM derailleur's idler wheel is not adjustable. Since it's calibrated for a bouncing mountain bike chain, the question is: will it be fully effective when used on a recumbent that has a 2-1/2 times, plus, longer chain?

What size would fit on the Musashi? short, medium, long?

Quote from jayg on Nov 12^th, 2013, 12:13pm:

 
Took the cover off the Musashi's X7 trigger shifter. Expected an explosion, and springs flying everywhere, but it didn't happen. Was surprised to find steel, not plastic, gears inside. There was grease inside, but not very much. I packed the gears with a white Teflon grease, put the cover back on, and installed the shifter back on the bike. Also, oiled the pivot points on the Rival derailler. Rode the bike today. Shifting is now a lot easier and the shifter/derailleur combo is indexing perfectly, like it used to. Fifteen cents of grease and oil fixed the problem. I'm expecting to receive a $180 package, tomorrow, containing a new X9 trigger shifter and a Type 2 X9 derailleur.

Installed a 2014 10-speed X9 trigger shifter and a medium cage, Type 2 X9 derailleur on my Carbent, instead of the Musashi, replacing an X9 shifter and long cage XO derailleur. Tested the new combo by putting  44 miles on the Carbent on Tuesday’s Clown ride.
 
The shifter is a new design (zero loss). When combined with the Type 2 derailleur it provided short  throw, perfectly-indexed up and down shifts on the flats and downhill. Downshifts were clean and easy when powering up hills. Up shifting was faster and not clunky, like the X9 shifter/X0 derailleur combo is (Probably due to the shorter cage on the X9). Performance was about the same as the X7 trigger shifter/Rival mid-cage derailleur combo on my Musashi, except powered, uphill down shifts were a little cleaner.
 
The X9 mid cage derailleur has a different geometry and 3/8” shorter cage than the Rival mid cage, accordingly it has less chainwrap capacity. I could cross chain from the 48T big ring to the 32T cog, but couldn’t shift to a cog smaller than 22T when in the 24T granny chainring. So, chainwrap capacity of the X9 derailleur is approximately 34T. Chainwrap capacity of the Rival is in excess of 39T. Would need a mid cage Rival or long cage X9 to enable cross chaining further towards the smaller cogs. Don’t foresee a need to do that, so the mid cage X9 is fine for my purposes.
 
The X9 clutching derailleur still allows the return chain to bounce a little between the idler and cassette (Per Bob M), but I’m thinking it would prevent the chain from jumping off the idler, if I happened to hit a pot hole.
 
The cable ramp on the X9 derailleur is the same as on the rest of  the X-Series derailleurs. Not the greatest design in my opinion, because the derailleur cable shreds prematurely at the ramp’s sharp edge. I had a fairly new cable installed on the Carbent, before I removed the X0 derailleur. Noticed the cable was already starting to shred when I removed the derailleur.
 
The new cage lock feature on the X9 makes wheel removal and chain breaking easy.
 
 

 
Chain on 48T big ring and 32T cassette cog.
 
 

 
Chain on 24T granny and 22T cassette cog.
 
 

 
Cage lock engaged for wheel removal or chain breaking.